2288 lines
98 KiB
Java
2288 lines
98 KiB
Java
/*
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* Copyright (c) 1994, 2019, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.lang;
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import java.io.BufferedInputStream;
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import java.io.BufferedOutputStream;
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import java.io.Console;
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import java.io.FileDescriptor;
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import java.io.FileInputStream;
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import java.io.FileOutputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import java.io.PrintStream;
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import java.io.UnsupportedEncodingException;
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import java.lang.annotation.Annotation;
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import java.lang.module.ModuleDescriptor;
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import java.lang.reflect.Constructor;
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import java.lang.reflect.Executable;
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import java.lang.reflect.Method;
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import java.lang.reflect.Modifier;
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import java.net.URI;
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import java.nio.charset.CharacterCodingException;
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import java.security.AccessControlContext;
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import java.security.ProtectionDomain;
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import java.security.AccessController;
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import java.security.PrivilegedAction;
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import java.nio.channels.Channel;
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import java.nio.channels.spi.SelectorProvider;
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import java.nio.charset.Charset;
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import java.util.Iterator;
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import java.util.List;
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import java.util.Map;
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import java.util.Objects;
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import java.util.Properties;
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import java.util.PropertyPermission;
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import java.util.ResourceBundle;
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import java.util.function.Supplier;
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import java.util.concurrent.ConcurrentHashMap;
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import java.util.stream.Stream;
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import jdk.internal.util.StaticProperty;
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import jdk.internal.module.ModuleBootstrap;
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import jdk.internal.module.ServicesCatalog;
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import jdk.internal.reflect.CallerSensitive;
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import jdk.internal.reflect.Reflection;
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import jdk.internal.HotSpotIntrinsicCandidate;
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import jdk.internal.access.JavaLangAccess;
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import jdk.internal.access.SharedSecrets;
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import jdk.internal.misc.VM;
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import jdk.internal.logger.LoggerFinderLoader;
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import jdk.internal.logger.LazyLoggers;
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import jdk.internal.logger.LocalizedLoggerWrapper;
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import jdk.internal.util.SystemProps;
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import jdk.internal.vm.annotation.Stable;
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import sun.nio.fs.DefaultFileSystemProvider;
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import sun.reflect.annotation.AnnotationType;
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import sun.nio.ch.Interruptible;
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import sun.security.util.SecurityConstants;
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/**
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* The {@code System} class contains several useful class fields
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* and methods. It cannot be instantiated.
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*
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* Among the facilities provided by the {@code System} class
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* are standard input, standard output, and error output streams;
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* access to externally defined properties and environment
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* variables; a means of loading files and libraries; and a utility
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* method for quickly copying a portion of an array.
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*
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* @since 1.0
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*/
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public final class System {
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/* Register the natives via the static initializer.
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*
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* The VM will invoke the initPhase1 method to complete the initialization
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* of this class separate from <clinit>.
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*/
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private static native void registerNatives();
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static {
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registerNatives();
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}
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/** Don't let anyone instantiate this class */
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private System() {
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}
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/**
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* The "standard" input stream. This stream is already
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* open and ready to supply input data. Typically this stream
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* corresponds to keyboard input or another input source specified by
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* the host environment or user.
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*/
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public static final InputStream in = null;
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/**
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* The "standard" output stream. This stream is already
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* open and ready to accept output data. Typically this stream
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* corresponds to display output or another output destination
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* specified by the host environment or user.
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* <p>
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* For simple stand-alone Java applications, a typical way to write
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* a line of output data is:
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* <blockquote><pre>
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* System.out.println(data)
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* </pre></blockquote>
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* <p>
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* See the {@code println} methods in class {@code PrintStream}.
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*
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* @see java.io.PrintStream#println()
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* @see java.io.PrintStream#println(boolean)
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* @see java.io.PrintStream#println(char)
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* @see java.io.PrintStream#println(char[])
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* @see java.io.PrintStream#println(double)
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* @see java.io.PrintStream#println(float)
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* @see java.io.PrintStream#println(int)
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* @see java.io.PrintStream#println(long)
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* @see java.io.PrintStream#println(java.lang.Object)
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* @see java.io.PrintStream#println(java.lang.String)
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*/
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public static final PrintStream out = null;
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/**
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* The "standard" error output stream. This stream is already
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* open and ready to accept output data.
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* <p>
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* Typically this stream corresponds to display output or another
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* output destination specified by the host environment or user. By
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* convention, this output stream is used to display error messages
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* or other information that should come to the immediate attention
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* of a user even if the principal output stream, the value of the
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* variable {@code out}, has been redirected to a file or other
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* destination that is typically not continuously monitored.
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*/
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public static final PrintStream err = null;
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// indicates if a security manager is possible
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private static final int NEVER = 1;
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private static final int MAYBE = 2;
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private static @Stable int allowSecurityManager;
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// current security manager
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private static volatile SecurityManager security; // read by VM
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// return true if a security manager is allowed
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private static boolean allowSecurityManager() {
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return (allowSecurityManager != NEVER);
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}
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/**
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* Reassigns the "standard" input stream.
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*
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* First, if there is a security manager, its {@code checkPermission}
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* method is called with a {@code RuntimePermission("setIO")} permission
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* to see if it's ok to reassign the "standard" input stream.
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*
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* @param in the new standard input stream.
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*
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* @throws SecurityException
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* if a security manager exists and its
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* {@code checkPermission} method doesn't allow
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* reassigning of the standard input stream.
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*
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* @see SecurityManager#checkPermission
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* @see java.lang.RuntimePermission
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*
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* @since 1.1
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*/
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public static void setIn(InputStream in) {
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checkIO();
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setIn0(in);
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}
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/**
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* Reassigns the "standard" output stream.
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*
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* First, if there is a security manager, its {@code checkPermission}
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* method is called with a {@code RuntimePermission("setIO")} permission
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* to see if it's ok to reassign the "standard" output stream.
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*
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* @param out the new standard output stream
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*
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* @throws SecurityException
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* if a security manager exists and its
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* {@code checkPermission} method doesn't allow
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* reassigning of the standard output stream.
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*
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* @see SecurityManager#checkPermission
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* @see java.lang.RuntimePermission
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*
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* @since 1.1
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*/
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public static void setOut(PrintStream out) {
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checkIO();
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setOut0(out);
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}
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/**
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* Reassigns the "standard" error output stream.
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*
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* First, if there is a security manager, its {@code checkPermission}
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* method is called with a {@code RuntimePermission("setIO")} permission
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* to see if it's ok to reassign the "standard" error output stream.
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*
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* @param err the new standard error output stream.
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*
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* @throws SecurityException
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* if a security manager exists and its
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* {@code checkPermission} method doesn't allow
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* reassigning of the standard error output stream.
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*
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* @see SecurityManager#checkPermission
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* @see java.lang.RuntimePermission
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*
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* @since 1.1
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*/
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public static void setErr(PrintStream err) {
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checkIO();
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setErr0(err);
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}
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private static volatile Console cons;
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/**
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* Returns the unique {@link java.io.Console Console} object associated
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* with the current Java virtual machine, if any.
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*
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* @return The system console, if any, otherwise {@code null}.
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*
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* @since 1.6
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*/
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public static Console console() {
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Console c;
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if ((c = cons) == null) {
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synchronized (System.class) {
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if ((c = cons) == null) {
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cons = c = SharedSecrets.getJavaIOAccess().console();
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}
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}
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}
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return c;
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}
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/**
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* Returns the channel inherited from the entity that created this
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* Java virtual machine.
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*
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* This method returns the channel obtained by invoking the
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* {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
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* inheritedChannel} method of the system-wide default
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* {@link java.nio.channels.spi.SelectorProvider} object.
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*
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* <p> In addition to the network-oriented channels described in
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* {@link java.nio.channels.spi.SelectorProvider#inheritedChannel
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* inheritedChannel}, this method may return other kinds of
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* channels in the future.
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*
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* @return The inherited channel, if any, otherwise {@code null}.
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*
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* @throws IOException
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* If an I/O error occurs
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*
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* @throws SecurityException
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* If a security manager is present and it does not
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* permit access to the channel.
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*
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* @since 1.5
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*/
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public static Channel inheritedChannel() throws IOException {
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return SelectorProvider.provider().inheritedChannel();
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}
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private static void checkIO() {
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SecurityManager sm = getSecurityManager();
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if (sm != null) {
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sm.checkPermission(new RuntimePermission("setIO"));
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}
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}
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private static native void setIn0(InputStream in);
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private static native void setOut0(PrintStream out);
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private static native void setErr0(PrintStream err);
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/**
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* Sets the system-wide security manager.
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*
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* If there is a security manager already installed, this method first
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* calls the security manager's {@code checkPermission} method
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* with a {@code RuntimePermission("setSecurityManager")}
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* permission to ensure it's ok to replace the existing
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* security manager.
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* This may result in throwing a {@code SecurityException}.
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*
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* <p> Otherwise, the argument is established as the current
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* security manager. If the argument is {@code null} and no
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* security manager has been established, then no action is taken and
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* the method simply returns.
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*
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* @implNote In the JDK implementation, if the Java virtual machine is
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* started with the system property {@code java.security.manager} set to
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* the special token "{@code disallow}" then the {@code setSecurityManager}
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* method cannot be used to set a security manager.
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*
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* @param sm the security manager or {@code null}
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* @throws SecurityException
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* if the security manager has already been set and its {@code
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* checkPermission} method doesn't allow it to be replaced
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* @throws UnsupportedOperationException
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* if {@code sm} is non-null and a security manager is not allowed
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* to be set dynamically
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* @see #getSecurityManager
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* @see SecurityManager#checkPermission
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* @see java.lang.RuntimePermission
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*/
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public static void setSecurityManager(SecurityManager sm) {
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if (allowSecurityManager()) {
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if (security == null) {
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// ensure image reader is initialized
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Object.class.getResource("java/lang/ANY");
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// ensure the default file system is initialized
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DefaultFileSystemProvider.theFileSystem();
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}
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if (sm != null) {
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try {
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// pre-populates the SecurityManager.packageAccess cache
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// to avoid recursive permission checking issues with custom
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// SecurityManager implementations
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sm.checkPackageAccess("java.lang");
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} catch (Exception e) {
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// no-op
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}
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}
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setSecurityManager0(sm);
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} else {
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// security manager not allowed
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if (sm != null) {
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throw new UnsupportedOperationException(
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"Runtime configured to disallow security manager");
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}
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}
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}
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private static synchronized
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void setSecurityManager0(final SecurityManager s) {
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SecurityManager sm = getSecurityManager();
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if (sm != null) {
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// ask the currently installed security manager if we
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// can replace it.
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sm.checkPermission(new RuntimePermission("setSecurityManager"));
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}
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if ((s != null) && (s.getClass().getClassLoader() != null)) {
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// New security manager class is not on bootstrap classpath.
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// Force policy to get initialized before we install the new
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// security manager, in order to prevent infinite loops when
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// trying to initialize the policy (which usually involves
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// accessing some security and/or system properties, which in turn
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// calls the installed security manager's checkPermission method
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// which will loop infinitely if there is a non-system class
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// (in this case: the new security manager class) on the stack).
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AccessController.doPrivileged(new PrivilegedAction<>() {
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public Object run() {
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s.getClass().getProtectionDomain().implies
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(SecurityConstants.ALL_PERMISSION);
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return null;
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}
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});
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}
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security = s;
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}
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/**
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* Gets the system-wide security manager.
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*
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* @return if a security manager has already been established for the
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* current application, then that security manager is returned;
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* otherwise, {@code null} is returned.
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* @see #setSecurityManager
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*/
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public static SecurityManager getSecurityManager() {
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if (allowSecurityManager()) {
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return security;
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} else {
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return null;
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}
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}
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/**
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* Returns the current time in milliseconds. Note that
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* while the unit of time of the return value is a millisecond,
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* the granularity of the value depends on the underlying
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* operating system and may be larger. For example, many
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* operating systems measure time in units of tens of
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* milliseconds.
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*
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* <p> See the description of the class {@code Date} for
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* a discussion of slight discrepancies that may arise between
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* "computer time" and coordinated universal time (UTC).
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*
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* @return the difference, measured in milliseconds, between
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* the current time and midnight, January 1, 1970 UTC.
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* @see java.util.Date
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*/
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@HotSpotIntrinsicCandidate
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public static native long currentTimeMillis();
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/**
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* Returns the current value of the running Java Virtual Machine's
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* high-resolution time source, in nanoseconds.
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*
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* This method can only be used to measure elapsed time and is
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* not related to any other notion of system or wall-clock time.
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* The value returned represents nanoseconds since some fixed but
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* arbitrary <i>origin</i> time (perhaps in the future, so values
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* may be negative). The same origin is used by all invocations of
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* this method in an instance of a Java virtual machine; other
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* virtual machine instances are likely to use a different origin.
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*
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* <p>This method provides nanosecond precision, but not necessarily
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* nanosecond resolution (that is, how frequently the value changes)
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* - no guarantees are made except that the resolution is at least as
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* good as that of {@link #currentTimeMillis()}.
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*
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* <p>Differences in successive calls that span greater than
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* approximately 292 years (2<sup>63</sup> nanoseconds) will not
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* correctly compute elapsed time due to numerical overflow.
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*
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* <p>The values returned by this method become meaningful only when
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* the difference between two such values, obtained within the same
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* instance of a Java virtual machine, is computed.
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*
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* <p>For example, to measure how long some code takes to execute:
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* <pre> {@code
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* long startTime = System.nanoTime();
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* // ... the code being measured ...
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* long elapsedNanos = System.nanoTime() - startTime;}</pre>
|
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*
|
|
* <p>To compare elapsed time against a timeout, use <pre> {@code
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* if (System.nanoTime() - startTime >= timeoutNanos) ...}</pre>
|
|
* instead of <pre> {@code
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* if (System.nanoTime() >= startTime + timeoutNanos) ...}</pre>
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* because of the possibility of numerical overflow.
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*
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* @return the current value of the running Java Virtual Machine's
|
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* high-resolution time source, in nanoseconds
|
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* @since 1.5
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*/
|
|
@HotSpotIntrinsicCandidate
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|
public static native long nanoTime();
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|
|
|
/**
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* Copies an array from the specified source array, beginning at the
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* specified position, to the specified position of the destination array.
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* A subsequence of array components are copied from the source
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* array referenced by {@code src} to the destination array
|
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* referenced by {@code dest}. The number of components copied is
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* equal to the {@code length} argument. The components at
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* positions {@code srcPos} through
|
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* {@code srcPos+length-1} in the source array are copied into
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* positions {@code destPos} through
|
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* {@code destPos+length-1}, respectively, of the destination
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* array.
|
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* <p>
|
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* If the {@code src} and {@code dest} arguments refer to the
|
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* same array object, then the copying is performed as if the
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* components at positions {@code srcPos} through
|
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* {@code srcPos+length-1} were first copied to a temporary
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* array with {@code length} components and then the contents of
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* the temporary array were copied into positions
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* {@code destPos} through {@code destPos+length-1} of the
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* destination array.
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* <p>
|
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* If {@code dest} is {@code null}, then a
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* {@code NullPointerException} is thrown.
|
|
* <p>
|
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* If {@code src} is {@code null}, then a
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* {@code NullPointerException} is thrown and the destination
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* array is not modified.
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|
* <p>
|
|
* Otherwise, if any of the following is true, an
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* {@code ArrayStoreException} is thrown and the destination is
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* not modified:
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* <ul>
|
|
* <li>The {@code src} argument refers to an object that is not an
|
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* array.
|
|
* <li>The {@code dest} argument refers to an object that is not an
|
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* array.
|
|
* <li>The {@code src} argument and {@code dest} argument refer
|
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* to arrays whose component types are different primitive types.
|
|
* <li>The {@code src} argument refers to an array with a primitive
|
|
* component type and the {@code dest} argument refers to an array
|
|
* with a reference component type.
|
|
* <li>The {@code src} argument refers to an array with a reference
|
|
* component type and the {@code dest} argument refers to an array
|
|
* with a primitive component type.
|
|
* </ul>
|
|
* <p>
|
|
* Otherwise, if any of the following is true, an
|
|
* {@code IndexOutOfBoundsException} is
|
|
* thrown and the destination is not modified:
|
|
* <ul>
|
|
* <li>The {@code srcPos} argument is negative.
|
|
* <li>The {@code destPos} argument is negative.
|
|
* <li>The {@code length} argument is negative.
|
|
* <li>{@code srcPos+length} is greater than
|
|
* {@code src.length}, the length of the source array.
|
|
* <li>{@code destPos+length} is greater than
|
|
* {@code dest.length}, the length of the destination array.
|
|
* </ul>
|
|
* <p>
|
|
* Otherwise, if any actual component of the source array from
|
|
* position {@code srcPos} through
|
|
* {@code srcPos+length-1} cannot be converted to the component
|
|
* type of the destination array by assignment conversion, an
|
|
* {@code ArrayStoreException} is thrown. In this case, let
|
|
* <b><i>k</i></b> be the smallest nonnegative integer less than
|
|
* length such that {@code src[srcPos+}<i>k</i>{@code ]}
|
|
* cannot be converted to the component type of the destination
|
|
* array; when the exception is thrown, source array components from
|
|
* positions {@code srcPos} through
|
|
* {@code srcPos+}<i>k</i>{@code -1}
|
|
* will already have been copied to destination array positions
|
|
* {@code destPos} through
|
|
* {@code destPos+}<i>k</I>{@code -1} and no other
|
|
* positions of the destination array will have been modified.
|
|
* (Because of the restrictions already itemized, this
|
|
* paragraph effectively applies only to the situation where both
|
|
* arrays have component types that are reference types.)
|
|
*
|
|
* @param src the source array.
|
|
* @param srcPos starting position in the source array.
|
|
* @param dest the destination array.
|
|
* @param destPos starting position in the destination data.
|
|
* @param length the number of array elements to be copied.
|
|
* @throws IndexOutOfBoundsException if copying would cause
|
|
* access of data outside array bounds.
|
|
* @throws ArrayStoreException if an element in the {@code src}
|
|
* array could not be stored into the {@code dest} array
|
|
* because of a type mismatch.
|
|
* @throws NullPointerException if either {@code src} or
|
|
* {@code dest} is {@code null}.
|
|
*/
|
|
@HotSpotIntrinsicCandidate
|
|
public static native void arraycopy(Object src, int srcPos,
|
|
Object dest, int destPos,
|
|
int length);
|
|
|
|
/**
|
|
* Returns the same hash code for the given object as
|
|
* would be returned by the default method hashCode(),
|
|
* whether or not the given object's class overrides
|
|
* hashCode().
|
|
* The hash code for the null reference is zero.
|
|
*
|
|
* @param x object for which the hashCode is to be calculated
|
|
* @return the hashCode
|
|
* @since 1.1
|
|
* @see Object#hashCode
|
|
* @see java.util.Objects#hashCode(Object)
|
|
*/
|
|
@HotSpotIntrinsicCandidate
|
|
public static native int identityHashCode(Object x);
|
|
|
|
/**
|
|
* System properties. The following properties are guaranteed to be defined:
|
|
* <dl>
|
|
* <dt>java.version <dd>Java version number
|
|
* <dt>java.version.date <dd>Java version date
|
|
* <dt>java.vendor <dd>Java vendor specific string
|
|
* <dt>java.vendor.url <dd>Java vendor URL
|
|
* <dt>java.vendor.version <dd>Java vendor version
|
|
* <dt>java.home <dd>Java installation directory
|
|
* <dt>java.class.version <dd>Java class version number
|
|
* <dt>java.class.path <dd>Java classpath
|
|
* <dt>os.name <dd>Operating System Name
|
|
* <dt>os.arch <dd>Operating System Architecture
|
|
* <dt>os.version <dd>Operating System Version
|
|
* <dt>file.separator <dd>File separator ("/" on Unix)
|
|
* <dt>path.separator <dd>Path separator (":" on Unix)
|
|
* <dt>line.separator <dd>Line separator ("\n" on Unix)
|
|
* <dt>user.name <dd>User account name
|
|
* <dt>user.home <dd>User home directory
|
|
* <dt>user.dir <dd>User's current working directory
|
|
* </dl>
|
|
*/
|
|
|
|
private static Properties props;
|
|
|
|
/**
|
|
* Determines the current system properties.
|
|
*
|
|
* First, if there is a security manager, its
|
|
* {@code checkPropertiesAccess} method is called with no
|
|
* arguments. This may result in a security exception.
|
|
* <p>
|
|
* The current set of system properties for use by the
|
|
* {@link #getProperty(String)} method is returned as a
|
|
* {@code Properties} object. If there is no current set of
|
|
* system properties, a set of system properties is first created and
|
|
* initialized. This set of system properties includes a value
|
|
* for each of the following keys unless the description of the associated
|
|
* value indicates that the value is optional.
|
|
* <table class="striped" style="text-align:left">
|
|
* <caption style="display:none">Shows property keys and associated values</caption>
|
|
* <thead>
|
|
* <tr><th scope="col">Key</th>
|
|
* <th scope="col">Description of Associated Value</th></tr>
|
|
* </thead>
|
|
* <tbody>
|
|
* <tr><th scope="row">{@systemProperty java.version}</th>
|
|
* <td>Java Runtime Environment version, which may be interpreted
|
|
* as a {@link Runtime.Version}</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.version.date}</th>
|
|
* <td>Java Runtime Environment version date, in ISO-8601 YYYY-MM-DD
|
|
* format, which may be interpreted as a {@link
|
|
* java.time.LocalDate}</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.vendor}</th>
|
|
* <td>Java Runtime Environment vendor</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.vendor.url}</th>
|
|
* <td>Java vendor URL</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.vendor.version}</th>
|
|
* <td>Java vendor version <em>(optional)</em> </td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.home}</th>
|
|
* <td>Java installation directory</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.vm.specification.version}</th>
|
|
* <td>Java Virtual Machine specification version, whose value is the
|
|
* {@linkplain Runtime.Version#feature feature} element of the
|
|
* {@linkplain Runtime#version() runtime version}</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.vm.specification.vendor}</th>
|
|
* <td>Java Virtual Machine specification vendor</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.vm.specification.name}</th>
|
|
* <td>Java Virtual Machine specification name</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.vm.version}</th>
|
|
* <td>Java Virtual Machine implementation version which may be
|
|
* interpreted as a {@link Runtime.Version}</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.vm.vendor}</th>
|
|
* <td>Java Virtual Machine implementation vendor</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.vm.name}</th>
|
|
* <td>Java Virtual Machine implementation name</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.specification.version}</th>
|
|
* <td>Java Runtime Environment specification version, whose value is
|
|
* the {@linkplain Runtime.Version#feature feature} element of the
|
|
* {@linkplain Runtime#version() runtime version}</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.specification.vendor}</th>
|
|
* <td>Java Runtime Environment specification vendor</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.specification.name}</th>
|
|
* <td>Java Runtime Environment specification name</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.class.version}</th>
|
|
* <td>Java class format version number</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.class.path}</th>
|
|
* <td>Java class path (refer to
|
|
* {@link ClassLoader#getSystemClassLoader()} for details)</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.library.path}</th>
|
|
* <td>List of paths to search when loading libraries</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.io.tmpdir}</th>
|
|
* <td>Default temp file path</td></tr>
|
|
* <tr><th scope="row">{@systemProperty java.compiler}</th>
|
|
* <td>Name of JIT compiler to use</td></tr>
|
|
* <tr><th scope="row">{@systemProperty os.name}</th>
|
|
* <td>Operating system name</td></tr>
|
|
* <tr><th scope="row">{@systemProperty os.arch}</th>
|
|
* <td>Operating system architecture</td></tr>
|
|
* <tr><th scope="row">{@systemProperty os.version}</th>
|
|
* <td>Operating system version</td></tr>
|
|
* <tr><th scope="row">{@systemProperty file.separator}</th>
|
|
* <td>File separator ("/" on UNIX)</td></tr>
|
|
* <tr><th scope="row">{@systemProperty path.separator}</th>
|
|
* <td>Path separator (":" on UNIX)</td></tr>
|
|
* <tr><th scope="row">{@systemProperty line.separator}</th>
|
|
* <td>Line separator ("\n" on UNIX)</td></tr>
|
|
* <tr><th scope="row">{@systemProperty user.name}</th>
|
|
* <td>User's account name</td></tr>
|
|
* <tr><th scope="row">{@systemProperty user.home}</th>
|
|
* <td>User's home directory</td></tr>
|
|
* <tr><th scope="row">{@systemProperty user.dir}</th>
|
|
* <td>User's current working directory</td></tr>
|
|
* </tbody>
|
|
* </table>
|
|
* <p>
|
|
* Multiple paths in a system property value are separated by the path
|
|
* separator character of the platform.
|
|
* <p>
|
|
* Note that even if the security manager does not permit the
|
|
* {@code getProperties} operation, it may choose to permit the
|
|
* {@link #getProperty(String)} operation.
|
|
*
|
|
* @apiNote
|
|
* <strong>Changing a standard system property may have unpredictable results
|
|
* unless otherwise specified.</strong>
|
|
* Property values may be cached during initialization or on first use.
|
|
* Setting a standard property after initialization using {@link #getProperties()},
|
|
* {@link #setProperties(Properties)}, {@link #setProperty(String, String)}, or
|
|
* {@link #clearProperty(String)} may not have the desired effect.
|
|
*
|
|
* @implNote
|
|
* In addition to the standard system properties, the system
|
|
* properties may include the following keys:
|
|
* <table class="striped">
|
|
* <caption style="display:none">Shows property keys and associated values</caption>
|
|
* <thead>
|
|
* <tr><th scope="col">Key</th>
|
|
* <th scope="col">Description of Associated Value</th></tr>
|
|
* </thead>
|
|
* <tbody>
|
|
* <tr><th scope="row">{@systemProperty jdk.module.path}</th>
|
|
* <td>The application module path</td></tr>
|
|
* <tr><th scope="row">{@systemProperty jdk.module.upgrade.path}</th>
|
|
* <td>The upgrade module path</td></tr>
|
|
* <tr><th scope="row">{@systemProperty jdk.module.main}</th>
|
|
* <td>The module name of the initial/main module</td></tr>
|
|
* <tr><th scope="row">{@systemProperty jdk.module.main.class}</th>
|
|
* <td>The main class name of the initial module</td></tr>
|
|
* </tbody>
|
|
* </table>
|
|
*
|
|
* @return the system properties
|
|
* @throws SecurityException if a security manager exists and its
|
|
* {@code checkPropertiesAccess} method doesn't allow access
|
|
* to the system properties.
|
|
* @see #setProperties
|
|
* @see java.lang.SecurityException
|
|
* @see java.lang.SecurityManager#checkPropertiesAccess()
|
|
* @see java.util.Properties
|
|
*/
|
|
public static Properties getProperties() {
|
|
SecurityManager sm = getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPropertiesAccess();
|
|
}
|
|
|
|
return props;
|
|
}
|
|
|
|
/**
|
|
* Returns the system-dependent line separator string. It always
|
|
* returns the same value - the initial value of the {@linkplain
|
|
* #getProperty(String) system property} {@code line.separator}.
|
|
*
|
|
* <p>On UNIX systems, it returns {@code "\n"}; on Microsoft
|
|
* Windows systems it returns {@code "\r\n"}.
|
|
*
|
|
* @return the system-dependent line separator string
|
|
* @since 1.7
|
|
*/
|
|
public static String lineSeparator() {
|
|
return lineSeparator;
|
|
}
|
|
|
|
private static String lineSeparator;
|
|
|
|
/**
|
|
* Sets the system properties to the {@code Properties} argument.
|
|
*
|
|
* First, if there is a security manager, its
|
|
* {@code checkPropertiesAccess} method is called with no
|
|
* arguments. This may result in a security exception.
|
|
* <p>
|
|
* The argument becomes the current set of system properties for use
|
|
* by the {@link #getProperty(String)} method. If the argument is
|
|
* {@code null}, then the current set of system properties is
|
|
* forgotten.
|
|
*
|
|
* @apiNote
|
|
* <strong>Changing a standard system property may have unpredictable results
|
|
* unless otherwise specified</strong>.
|
|
* See {@linkplain #getProperties getProperties} for details.
|
|
*
|
|
* @param props the new system properties.
|
|
* @throws SecurityException if a security manager exists and its
|
|
* {@code checkPropertiesAccess} method doesn't allow access
|
|
* to the system properties.
|
|
* @see #getProperties
|
|
* @see java.util.Properties
|
|
* @see java.lang.SecurityException
|
|
* @see java.lang.SecurityManager#checkPropertiesAccess()
|
|
*/
|
|
public static void setProperties(Properties props) {
|
|
SecurityManager sm = getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPropertiesAccess();
|
|
}
|
|
|
|
if (props == null) {
|
|
Map<String, String> tempProps = SystemProps.initProperties();
|
|
VersionProps.init(tempProps);
|
|
props = createProperties(tempProps);
|
|
}
|
|
System.props = props;
|
|
}
|
|
|
|
/**
|
|
* Gets the system property indicated by the specified key.
|
|
*
|
|
* First, if there is a security manager, its
|
|
* {@code checkPropertyAccess} method is called with the key as
|
|
* its argument. This may result in a SecurityException.
|
|
* <p>
|
|
* If there is no current set of system properties, a set of system
|
|
* properties is first created and initialized in the same manner as
|
|
* for the {@code getProperties} method.
|
|
*
|
|
* @apiNote
|
|
* <strong>Changing a standard system property may have unpredictable results
|
|
* unless otherwise specified</strong>.
|
|
* See {@linkplain #getProperties getProperties} for details.
|
|
*
|
|
* @param key the name of the system property.
|
|
* @return the string value of the system property,
|
|
* or {@code null} if there is no property with that key.
|
|
*
|
|
* @throws SecurityException if a security manager exists and its
|
|
* {@code checkPropertyAccess} method doesn't allow
|
|
* access to the specified system property.
|
|
* @throws NullPointerException if {@code key} is {@code null}.
|
|
* @throws IllegalArgumentException if {@code key} is empty.
|
|
* @see #setProperty
|
|
* @see java.lang.SecurityException
|
|
* @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
|
|
* @see java.lang.System#getProperties()
|
|
*/
|
|
public static String getProperty(String key) {
|
|
checkKey(key);
|
|
SecurityManager sm = getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPropertyAccess(key);
|
|
}
|
|
|
|
return props.getProperty(key);
|
|
}
|
|
|
|
/**
|
|
* Gets the system property indicated by the specified key.
|
|
*
|
|
* First, if there is a security manager, its
|
|
* {@code checkPropertyAccess} method is called with the
|
|
* {@code key} as its argument.
|
|
* <p>
|
|
* If there is no current set of system properties, a set of system
|
|
* properties is first created and initialized in the same manner as
|
|
* for the {@code getProperties} method.
|
|
*
|
|
* @param key the name of the system property.
|
|
* @param def a default value.
|
|
* @return the string value of the system property,
|
|
* or the default value if there is no property with that key.
|
|
*
|
|
* @throws SecurityException if a security manager exists and its
|
|
* {@code checkPropertyAccess} method doesn't allow
|
|
* access to the specified system property.
|
|
* @throws NullPointerException if {@code key} is {@code null}.
|
|
* @throws IllegalArgumentException if {@code key} is empty.
|
|
* @see #setProperty
|
|
* @see java.lang.SecurityManager#checkPropertyAccess(java.lang.String)
|
|
* @see java.lang.System#getProperties()
|
|
*/
|
|
public static String getProperty(String key, String def) {
|
|
checkKey(key);
|
|
SecurityManager sm = getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPropertyAccess(key);
|
|
}
|
|
|
|
return props.getProperty(key, def);
|
|
}
|
|
|
|
/**
|
|
* Sets the system property indicated by the specified key.
|
|
*
|
|
* First, if a security manager exists, its
|
|
* {@code SecurityManager.checkPermission} method
|
|
* is called with a {@code PropertyPermission(key, "write")}
|
|
* permission. This may result in a SecurityException being thrown.
|
|
* If no exception is thrown, the specified property is set to the given
|
|
* value.
|
|
*
|
|
* @apiNote
|
|
* <strong>Changing a standard system property may have unpredictable results
|
|
* unless otherwise specified</strong>.
|
|
* See {@linkplain #getProperties getProperties} for details.
|
|
*
|
|
* @param key the name of the system property.
|
|
* @param value the value of the system property.
|
|
* @return the previous value of the system property,
|
|
* or {@code null} if it did not have one.
|
|
*
|
|
* @throws SecurityException if a security manager exists and its
|
|
* {@code checkPermission} method doesn't allow
|
|
* setting of the specified property.
|
|
* @throws NullPointerException if {@code key} or
|
|
* {@code value} is {@code null}.
|
|
* @throws IllegalArgumentException if {@code key} is empty.
|
|
* @see #getProperty
|
|
* @see java.lang.System#getProperty(java.lang.String)
|
|
* @see java.lang.System#getProperty(java.lang.String, java.lang.String)
|
|
* @see java.util.PropertyPermission
|
|
* @see SecurityManager#checkPermission
|
|
* @since 1.2
|
|
*/
|
|
public static String setProperty(String key, String value) {
|
|
checkKey(key);
|
|
SecurityManager sm = getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPermission(new PropertyPermission(key,
|
|
SecurityConstants.PROPERTY_WRITE_ACTION));
|
|
}
|
|
|
|
return (String) props.setProperty(key, value);
|
|
}
|
|
|
|
/**
|
|
* Removes the system property indicated by the specified key.
|
|
*
|
|
* First, if a security manager exists, its
|
|
* {@code SecurityManager.checkPermission} method
|
|
* is called with a {@code PropertyPermission(key, "write")}
|
|
* permission. This may result in a SecurityException being thrown.
|
|
* If no exception is thrown, the specified property is removed.
|
|
*
|
|
* @apiNote
|
|
* <strong>Changing a standard system property may have unpredictable results
|
|
* unless otherwise specified</strong>.
|
|
* See {@linkplain #getProperties getProperties} method for details.
|
|
*
|
|
* @param key the name of the system property to be removed.
|
|
* @return the previous string value of the system property,
|
|
* or {@code null} if there was no property with that key.
|
|
*
|
|
* @throws SecurityException if a security manager exists and its
|
|
* {@code checkPropertyAccess} method doesn't allow
|
|
* access to the specified system property.
|
|
* @throws NullPointerException if {@code key} is {@code null}.
|
|
* @throws IllegalArgumentException if {@code key} is empty.
|
|
* @see #getProperty
|
|
* @see #setProperty
|
|
* @see java.util.Properties
|
|
* @see java.lang.SecurityException
|
|
* @see java.lang.SecurityManager#checkPropertiesAccess()
|
|
* @since 1.5
|
|
*/
|
|
public static String clearProperty(String key) {
|
|
checkKey(key);
|
|
SecurityManager sm = getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPermission(new PropertyPermission(key, "write"));
|
|
}
|
|
|
|
return (String) props.remove(key);
|
|
}
|
|
|
|
private static void checkKey(String key) {
|
|
if (key == null) {
|
|
throw new NullPointerException("key can't be null");
|
|
}
|
|
if (key.isEmpty()) {
|
|
throw new IllegalArgumentException("key can't be empty");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Gets the value of the specified environment variable. An
|
|
* environment variable is a system-dependent external named
|
|
* value.
|
|
*
|
|
* <p>If a security manager exists, its
|
|
* {@link SecurityManager#checkPermission checkPermission}
|
|
* method is called with a
|
|
* {@link RuntimePermission RuntimePermission("getenv."+name)}
|
|
* permission. This may result in a {@link SecurityException}
|
|
* being thrown. If no exception is thrown the value of the
|
|
* variable {@code name} is returned.
|
|
*
|
|
* <p><a id="EnvironmentVSSystemProperties"><i>System
|
|
* properties</i> and <i>environment variables</i></a> are both
|
|
* conceptually mappings between names and values. Both
|
|
* mechanisms can be used to pass user-defined information to a
|
|
* Java process. Environment variables have a more global effect,
|
|
* because they are visible to all descendants of the process
|
|
* which defines them, not just the immediate Java subprocess.
|
|
* They can have subtly different semantics, such as case
|
|
* insensitivity, on different operating systems. For these
|
|
* reasons, environment variables are more likely to have
|
|
* unintended side effects. It is best to use system properties
|
|
* where possible. Environment variables should be used when a
|
|
* global effect is desired, or when an external system interface
|
|
* requires an environment variable (such as {@code PATH}).
|
|
*
|
|
* <p>On UNIX systems the alphabetic case of {@code name} is
|
|
* typically significant, while on Microsoft Windows systems it is
|
|
* typically not. For example, the expression
|
|
* {@code System.getenv("FOO").equals(System.getenv("foo"))}
|
|
* is likely to be true on Microsoft Windows.
|
|
*
|
|
* @param name the name of the environment variable
|
|
* @return the string value of the variable, or {@code null}
|
|
* if the variable is not defined in the system environment
|
|
* @throws NullPointerException if {@code name} is {@code null}
|
|
* @throws SecurityException
|
|
* if a security manager exists and its
|
|
* {@link SecurityManager#checkPermission checkPermission}
|
|
* method doesn't allow access to the environment variable
|
|
* {@code name}
|
|
* @see #getenv()
|
|
* @see ProcessBuilder#environment()
|
|
*/
|
|
public static String getenv(String name) {
|
|
SecurityManager sm = getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPermission(new RuntimePermission("getenv."+name));
|
|
}
|
|
|
|
return ProcessEnvironment.getenv(name);
|
|
}
|
|
|
|
|
|
/**
|
|
* Returns an unmodifiable string map view of the current system environment.
|
|
* The environment is a system-dependent mapping from names to
|
|
* values which is passed from parent to child processes.
|
|
*
|
|
* <p>If the system does not support environment variables, an
|
|
* empty map is returned.
|
|
*
|
|
* <p>The returned map will never contain null keys or values.
|
|
* Attempting to query the presence of a null key or value will
|
|
* throw a {@link NullPointerException}. Attempting to query
|
|
* the presence of a key or value which is not of type
|
|
* {@link String} will throw a {@link ClassCastException}.
|
|
*
|
|
* <p>The returned map and its collection views may not obey the
|
|
* general contract of the {@link Object#equals} and
|
|
* {@link Object#hashCode} methods.
|
|
*
|
|
* <p>The returned map is typically case-sensitive on all platforms.
|
|
*
|
|
* <p>If a security manager exists, its
|
|
* {@link SecurityManager#checkPermission checkPermission}
|
|
* method is called with a
|
|
* {@link RuntimePermission RuntimePermission("getenv.*")} permission.
|
|
* This may result in a {@link SecurityException} being thrown.
|
|
*
|
|
* <p>When passing information to a Java subprocess,
|
|
* <a href=#EnvironmentVSSystemProperties>system properties</a>
|
|
* are generally preferred over environment variables.
|
|
*
|
|
* @return the environment as a map of variable names to values
|
|
* @throws SecurityException
|
|
* if a security manager exists and its
|
|
* {@link SecurityManager#checkPermission checkPermission}
|
|
* method doesn't allow access to the process environment
|
|
* @see #getenv(String)
|
|
* @see ProcessBuilder#environment()
|
|
* @since 1.5
|
|
*/
|
|
public static java.util.Map<String,String> getenv() {
|
|
SecurityManager sm = getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPermission(new RuntimePermission("getenv.*"));
|
|
}
|
|
|
|
return ProcessEnvironment.getenv();
|
|
}
|
|
|
|
/**
|
|
* {@code System.Logger} instances log messages that will be
|
|
* routed to the underlying logging framework the {@link System.LoggerFinder
|
|
* LoggerFinder} uses.
|
|
*
|
|
* {@code System.Logger} instances are typically obtained from
|
|
* the {@link java.lang.System System} class, by calling
|
|
* {@link java.lang.System#getLogger(java.lang.String) System.getLogger(loggerName)}
|
|
* or {@link java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
|
|
* System.getLogger(loggerName, bundle)}.
|
|
*
|
|
* @see java.lang.System#getLogger(java.lang.String)
|
|
* @see java.lang.System#getLogger(java.lang.String, java.util.ResourceBundle)
|
|
* @see java.lang.System.LoggerFinder
|
|
*
|
|
* @since 9
|
|
*/
|
|
public interface Logger {
|
|
|
|
/**
|
|
* System {@linkplain Logger loggers} levels.
|
|
*
|
|
* A level has a {@linkplain #getName() name} and {@linkplain
|
|
* #getSeverity() severity}.
|
|
* Level values are {@link #ALL}, {@link #TRACE}, {@link #DEBUG},
|
|
* {@link #INFO}, {@link #WARNING}, {@link #ERROR}, {@link #OFF},
|
|
* by order of increasing severity.
|
|
* <br>
|
|
* {@link #ALL} and {@link #OFF}
|
|
* are simple markers with severities mapped respectively to
|
|
* {@link java.lang.Integer#MIN_VALUE Integer.MIN_VALUE} and
|
|
* {@link java.lang.Integer#MAX_VALUE Integer.MAX_VALUE}.
|
|
* <p>
|
|
* <b>Severity values and Mapping to {@code java.util.logging.Level}.</b>
|
|
* <p>
|
|
* {@linkplain System.Logger.Level System logger levels} are mapped to
|
|
* {@linkplain java.util.logging.Level java.util.logging levels}
|
|
* of corresponding severity.
|
|
* <br>The mapping is as follows:
|
|
* <br><br>
|
|
* <table class="striped">
|
|
* <caption>System.Logger Severity Level Mapping</caption>
|
|
* <thead>
|
|
* <tr><th scope="col">System.Logger Levels</th>
|
|
* <th scope="col">java.util.logging Levels</th>
|
|
* </thead>
|
|
* <tbody>
|
|
* <tr><th scope="row">{@link Logger.Level#ALL ALL}</th>
|
|
* <td>{@link java.util.logging.Level#ALL ALL}</td>
|
|
* <tr><th scope="row">{@link Logger.Level#TRACE TRACE}</th>
|
|
* <td>{@link java.util.logging.Level#FINER FINER}</td>
|
|
* <tr><th scope="row">{@link Logger.Level#DEBUG DEBUG}</th>
|
|
* <td>{@link java.util.logging.Level#FINE FINE}</td>
|
|
* <tr><th scope="row">{@link Logger.Level#INFO INFO}</th>
|
|
* <td>{@link java.util.logging.Level#INFO INFO}</td>
|
|
* <tr><th scope="row">{@link Logger.Level#WARNING WARNING}</th>
|
|
* <td>{@link java.util.logging.Level#WARNING WARNING}</td>
|
|
* <tr><th scope="row">{@link Logger.Level#ERROR ERROR}</th>
|
|
* <td>{@link java.util.logging.Level#SEVERE SEVERE}</td>
|
|
* <tr><th scope="row">{@link Logger.Level#OFF OFF}</th>
|
|
* <td>{@link java.util.logging.Level#OFF OFF}</td>
|
|
* </tbody>
|
|
* </table>
|
|
*
|
|
* @since 9
|
|
*
|
|
* @see java.lang.System.LoggerFinder
|
|
* @see java.lang.System.Logger
|
|
*/
|
|
public enum Level {
|
|
|
|
// for convenience, we're reusing java.util.logging.Level int values
|
|
// the mapping logic in sun.util.logging.PlatformLogger depends
|
|
// on this.
|
|
/**
|
|
* A marker to indicate that all levels are enabled.
|
|
* This level {@linkplain #getSeverity() severity} is
|
|
* {@link Integer#MIN_VALUE}.
|
|
*/
|
|
ALL(Integer.MIN_VALUE), // typically mapped to/from j.u.l.Level.ALL
|
|
/**
|
|
* {@code TRACE} level: usually used to log diagnostic information.
|
|
* This level {@linkplain #getSeverity() severity} is
|
|
* {@code 400}.
|
|
*/
|
|
TRACE(400), // typically mapped to/from j.u.l.Level.FINER
|
|
/**
|
|
* {@code DEBUG} level: usually used to log debug information traces.
|
|
* This level {@linkplain #getSeverity() severity} is
|
|
* {@code 500}.
|
|
*/
|
|
DEBUG(500), // typically mapped to/from j.u.l.Level.FINEST/FINE/CONFIG
|
|
/**
|
|
* {@code INFO} level: usually used to log information messages.
|
|
* This level {@linkplain #getSeverity() severity} is
|
|
* {@code 800}.
|
|
*/
|
|
INFO(800), // typically mapped to/from j.u.l.Level.INFO
|
|
/**
|
|
* {@code WARNING} level: usually used to log warning messages.
|
|
* This level {@linkplain #getSeverity() severity} is
|
|
* {@code 900}.
|
|
*/
|
|
WARNING(900), // typically mapped to/from j.u.l.Level.WARNING
|
|
/**
|
|
* {@code ERROR} level: usually used to log error messages.
|
|
* This level {@linkplain #getSeverity() severity} is
|
|
* {@code 1000}.
|
|
*/
|
|
ERROR(1000), // typically mapped to/from j.u.l.Level.SEVERE
|
|
/**
|
|
* A marker to indicate that all levels are disabled.
|
|
* This level {@linkplain #getSeverity() severity} is
|
|
* {@link Integer#MAX_VALUE}.
|
|
*/
|
|
OFF(Integer.MAX_VALUE); // typically mapped to/from j.u.l.Level.OFF
|
|
|
|
private final int severity;
|
|
|
|
private Level(int severity) {
|
|
this.severity = severity;
|
|
}
|
|
|
|
/**
|
|
* Returns the name of this level.
|
|
* @return this level {@linkplain #name()}.
|
|
*/
|
|
public final String getName() {
|
|
return name();
|
|
}
|
|
|
|
/**
|
|
* Returns the severity of this level.
|
|
* A higher severity means a more severe condition.
|
|
* @return this level severity.
|
|
*/
|
|
public final int getSeverity() {
|
|
return severity;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns the name of this logger.
|
|
*
|
|
* @return the logger name.
|
|
*/
|
|
public String getName();
|
|
|
|
/**
|
|
* Checks if a message of the given level would be logged by
|
|
* this logger.
|
|
*
|
|
* @param level the log message level.
|
|
* @return {@code true} if the given log message level is currently
|
|
* being logged.
|
|
*
|
|
* @throws NullPointerException if {@code level} is {@code null}.
|
|
*/
|
|
public boolean isLoggable(Level level);
|
|
|
|
/**
|
|
* Logs a message.
|
|
*
|
|
* @implSpec The default implementation for this method calls
|
|
* {@code this.log(level, (ResourceBundle)null, msg, (Object[])null);}
|
|
*
|
|
* @param level the log message level.
|
|
* @param msg the string message (or a key in the message catalog, if
|
|
* this logger is a {@link
|
|
* LoggerFinder#getLocalizedLogger(java.lang.String,
|
|
* java.util.ResourceBundle, java.lang.Module) localized logger});
|
|
* can be {@code null}.
|
|
*
|
|
* @throws NullPointerException if {@code level} is {@code null}.
|
|
*/
|
|
public default void log(Level level, String msg) {
|
|
log(level, (ResourceBundle) null, msg, (Object[]) null);
|
|
}
|
|
|
|
/**
|
|
* Logs a lazily supplied message.
|
|
*
|
|
* If the logger is currently enabled for the given log message level
|
|
* then a message is logged that is the result produced by the
|
|
* given supplier function. Otherwise, the supplier is not operated on.
|
|
*
|
|
* @implSpec When logging is enabled for the given level, the default
|
|
* implementation for this method calls
|
|
* {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), (Object[])null);}
|
|
*
|
|
* @param level the log message level.
|
|
* @param msgSupplier a supplier function that produces a message.
|
|
*
|
|
* @throws NullPointerException if {@code level} is {@code null},
|
|
* or {@code msgSupplier} is {@code null}.
|
|
*/
|
|
public default void log(Level level, Supplier<String> msgSupplier) {
|
|
Objects.requireNonNull(msgSupplier);
|
|
if (isLoggable(Objects.requireNonNull(level))) {
|
|
log(level, (ResourceBundle) null, msgSupplier.get(), (Object[]) null);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Logs a message produced from the given object.
|
|
*
|
|
* If the logger is currently enabled for the given log message level then
|
|
* a message is logged that, by default, is the result produced from
|
|
* calling toString on the given object.
|
|
* Otherwise, the object is not operated on.
|
|
*
|
|
* @implSpec When logging is enabled for the given level, the default
|
|
* implementation for this method calls
|
|
* {@code this.log(level, (ResourceBundle)null, obj.toString(), (Object[])null);}
|
|
*
|
|
* @param level the log message level.
|
|
* @param obj the object to log.
|
|
*
|
|
* @throws NullPointerException if {@code level} is {@code null}, or
|
|
* {@code obj} is {@code null}.
|
|
*/
|
|
public default void log(Level level, Object obj) {
|
|
Objects.requireNonNull(obj);
|
|
if (isLoggable(Objects.requireNonNull(level))) {
|
|
this.log(level, (ResourceBundle) null, obj.toString(), (Object[]) null);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Logs a message associated with a given throwable.
|
|
*
|
|
* @implSpec The default implementation for this method calls
|
|
* {@code this.log(level, (ResourceBundle)null, msg, thrown);}
|
|
*
|
|
* @param level the log message level.
|
|
* @param msg the string message (or a key in the message catalog, if
|
|
* this logger is a {@link
|
|
* LoggerFinder#getLocalizedLogger(java.lang.String,
|
|
* java.util.ResourceBundle, java.lang.Module) localized logger});
|
|
* can be {@code null}.
|
|
* @param thrown a {@code Throwable} associated with the log message;
|
|
* can be {@code null}.
|
|
*
|
|
* @throws NullPointerException if {@code level} is {@code null}.
|
|
*/
|
|
public default void log(Level level, String msg, Throwable thrown) {
|
|
this.log(level, null, msg, thrown);
|
|
}
|
|
|
|
/**
|
|
* Logs a lazily supplied message associated with a given throwable.
|
|
*
|
|
* If the logger is currently enabled for the given log message level
|
|
* then a message is logged that is the result produced by the
|
|
* given supplier function. Otherwise, the supplier is not operated on.
|
|
*
|
|
* @implSpec When logging is enabled for the given level, the default
|
|
* implementation for this method calls
|
|
* {@code this.log(level, (ResourceBundle)null, msgSupplier.get(), thrown);}
|
|
*
|
|
* @param level one of the log message level identifiers.
|
|
* @param msgSupplier a supplier function that produces a message.
|
|
* @param thrown a {@code Throwable} associated with log message;
|
|
* can be {@code null}.
|
|
*
|
|
* @throws NullPointerException if {@code level} is {@code null}, or
|
|
* {@code msgSupplier} is {@code null}.
|
|
*/
|
|
public default void log(Level level, Supplier<String> msgSupplier,
|
|
Throwable thrown) {
|
|
Objects.requireNonNull(msgSupplier);
|
|
if (isLoggable(Objects.requireNonNull(level))) {
|
|
this.log(level, null, msgSupplier.get(), thrown);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Logs a message with an optional list of parameters.
|
|
*
|
|
* @implSpec The default implementation for this method calls
|
|
* {@code this.log(level, (ResourceBundle)null, format, params);}
|
|
*
|
|
* @param level one of the log message level identifiers.
|
|
* @param format the string message format in {@link
|
|
* java.text.MessageFormat} format, (or a key in the message
|
|
* catalog, if this logger is a {@link
|
|
* LoggerFinder#getLocalizedLogger(java.lang.String,
|
|
* java.util.ResourceBundle, java.lang.Module) localized logger});
|
|
* can be {@code null}.
|
|
* @param params an optional list of parameters to the message (may be
|
|
* none).
|
|
*
|
|
* @throws NullPointerException if {@code level} is {@code null}.
|
|
*/
|
|
public default void log(Level level, String format, Object... params) {
|
|
this.log(level, null, format, params);
|
|
}
|
|
|
|
/**
|
|
* Logs a localized message associated with a given throwable.
|
|
*
|
|
* If the given resource bundle is non-{@code null}, the {@code msg}
|
|
* string is localized using the given resource bundle.
|
|
* Otherwise the {@code msg} string is not localized.
|
|
*
|
|
* @param level the log message level.
|
|
* @param bundle a resource bundle to localize {@code msg}; can be
|
|
* {@code null}.
|
|
* @param msg the string message (or a key in the message catalog,
|
|
* if {@code bundle} is not {@code null}); can be {@code null}.
|
|
* @param thrown a {@code Throwable} associated with the log message;
|
|
* can be {@code null}.
|
|
*
|
|
* @throws NullPointerException if {@code level} is {@code null}.
|
|
*/
|
|
public void log(Level level, ResourceBundle bundle, String msg,
|
|
Throwable thrown);
|
|
|
|
/**
|
|
* Logs a message with resource bundle and an optional list of
|
|
* parameters.
|
|
*
|
|
* If the given resource bundle is non-{@code null}, the {@code format}
|
|
* string is localized using the given resource bundle.
|
|
* Otherwise the {@code format} string is not localized.
|
|
*
|
|
* @param level the log message level.
|
|
* @param bundle a resource bundle to localize {@code format}; can be
|
|
* {@code null}.
|
|
* @param format the string message format in {@link
|
|
* java.text.MessageFormat} format, (or a key in the message
|
|
* catalog if {@code bundle} is not {@code null}); can be {@code null}.
|
|
* @param params an optional list of parameters to the message (may be
|
|
* none).
|
|
*
|
|
* @throws NullPointerException if {@code level} is {@code null}.
|
|
*/
|
|
public void log(Level level, ResourceBundle bundle, String format,
|
|
Object... params);
|
|
}
|
|
|
|
/**
|
|
* The {@code LoggerFinder} service is responsible for creating, managing,
|
|
* and configuring loggers to the underlying framework it uses.
|
|
*
|
|
* A logger finder is a concrete implementation of this class that has a
|
|
* zero-argument constructor and implements the abstract methods defined
|
|
* by this class.
|
|
* The loggers returned from a logger finder are capable of routing log
|
|
* messages to the logging backend this provider supports.
|
|
* A given invocation of the Java Runtime maintains a single
|
|
* system-wide LoggerFinder instance that is loaded as follows:
|
|
* <ul>
|
|
* <li>First it finds any custom {@code LoggerFinder} provider
|
|
* using the {@link java.util.ServiceLoader} facility with the
|
|
* {@linkplain ClassLoader#getSystemClassLoader() system class
|
|
* loader}.</li>
|
|
* <li>If no {@code LoggerFinder} provider is found, the system default
|
|
* {@code LoggerFinder} implementation will be used.</li>
|
|
* </ul>
|
|
* <p>
|
|
* An application can replace the logging backend
|
|
* <i>even when the java.logging module is present</i>, by simply providing
|
|
* and declaring an implementation of the {@link LoggerFinder} service.
|
|
* <p>
|
|
* <b>Default Implementation</b>
|
|
* <p>
|
|
* The system default {@code LoggerFinder} implementation uses
|
|
* {@code java.util.logging} as the backend framework when the
|
|
* {@code java.logging} module is present.
|
|
* It returns a {@linkplain System.Logger logger} instance
|
|
* that will route log messages to a {@link java.util.logging.Logger
|
|
* java.util.logging.Logger}. Otherwise, if {@code java.logging} is not
|
|
* present, the default implementation will return a simple logger
|
|
* instance that will route log messages of {@code INFO} level and above to
|
|
* the console ({@code System.err}).
|
|
* <p>
|
|
* <b>Logging Configuration</b>
|
|
* <p>
|
|
* {@linkplain Logger Logger} instances obtained from the
|
|
* {@code LoggerFinder} factory methods are not directly configurable by
|
|
* the application. Configuration is the responsibility of the underlying
|
|
* logging backend, and usually requires using APIs specific to that backend.
|
|
* <p>For the default {@code LoggerFinder} implementation
|
|
* using {@code java.util.logging} as its backend, refer to
|
|
* {@link java.util.logging java.util.logging} for logging configuration.
|
|
* For the default {@code LoggerFinder} implementation returning simple loggers
|
|
* when the {@code java.logging} module is absent, the configuration
|
|
* is implementation dependent.
|
|
* <p>
|
|
* Usually an application that uses a logging framework will log messages
|
|
* through a logger facade defined (or supported) by that framework.
|
|
* Applications that wish to use an external framework should log
|
|
* through the facade associated with that framework.
|
|
* <p>
|
|
* A system class that needs to log messages will typically obtain
|
|
* a {@link System.Logger} instance to route messages to the logging
|
|
* framework selected by the application.
|
|
* <p>
|
|
* Libraries and classes that only need loggers to produce log messages
|
|
* should not attempt to configure loggers by themselves, as that
|
|
* would make them dependent from a specific implementation of the
|
|
* {@code LoggerFinder} service.
|
|
* <p>
|
|
* In addition, when a security manager is present, loggers provided to
|
|
* system classes should not be directly configurable through the logging
|
|
* backend without requiring permissions.
|
|
* <br>
|
|
* It is the responsibility of the provider of
|
|
* the concrete {@code LoggerFinder} implementation to ensure that
|
|
* these loggers are not configured by untrusted code without proper
|
|
* permission checks, as configuration performed on such loggers usually
|
|
* affects all applications in the same Java Runtime.
|
|
* <p>
|
|
* <b>Message Levels and Mapping to backend levels</b>
|
|
* <p>
|
|
* A logger finder is responsible for mapping from a {@code
|
|
* System.Logger.Level} to a level supported by the logging backend it uses.
|
|
* <br>The default LoggerFinder using {@code java.util.logging} as the backend
|
|
* maps {@code System.Logger} levels to
|
|
* {@linkplain java.util.logging.Level java.util.logging} levels
|
|
* of corresponding severity - as described in {@link Logger.Level
|
|
* Logger.Level}.
|
|
*
|
|
* @see java.lang.System
|
|
* @see java.lang.System.Logger
|
|
*
|
|
* @since 9
|
|
*/
|
|
public static abstract class LoggerFinder {
|
|
/**
|
|
* The {@code RuntimePermission("loggerFinder")} is
|
|
* necessary to subclass and instantiate the {@code LoggerFinder} class,
|
|
* as well as to obtain loggers from an instance of that class.
|
|
*/
|
|
static final RuntimePermission LOGGERFINDER_PERMISSION =
|
|
new RuntimePermission("loggerFinder");
|
|
|
|
/**
|
|
* Creates a new instance of {@code LoggerFinder}.
|
|
*
|
|
* @implNote It is recommended that a {@code LoggerFinder} service
|
|
* implementation does not perform any heavy initialization in its
|
|
* constructor, in order to avoid possible risks of deadlock or class
|
|
* loading cycles during the instantiation of the service provider.
|
|
*
|
|
* @throws SecurityException if a security manager is present and its
|
|
* {@code checkPermission} method doesn't allow the
|
|
* {@code RuntimePermission("loggerFinder")}.
|
|
*/
|
|
protected LoggerFinder() {
|
|
this(checkPermission());
|
|
}
|
|
|
|
private LoggerFinder(Void unused) {
|
|
// nothing to do.
|
|
}
|
|
|
|
private static Void checkPermission() {
|
|
final SecurityManager sm = System.getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPermission(LOGGERFINDER_PERMISSION);
|
|
}
|
|
return null;
|
|
}
|
|
|
|
/**
|
|
* Returns an instance of {@link Logger Logger}
|
|
* for the given {@code module}.
|
|
*
|
|
* @param name the name of the logger.
|
|
* @param module the module for which the logger is being requested.
|
|
*
|
|
* @return a {@link Logger logger} suitable for use within the given
|
|
* module.
|
|
* @throws NullPointerException if {@code name} is {@code null} or
|
|
* {@code module} is {@code null}.
|
|
* @throws SecurityException if a security manager is present and its
|
|
* {@code checkPermission} method doesn't allow the
|
|
* {@code RuntimePermission("loggerFinder")}.
|
|
*/
|
|
public abstract Logger getLogger(String name, Module module);
|
|
|
|
/**
|
|
* Returns a localizable instance of {@link Logger Logger}
|
|
* for the given {@code module}.
|
|
* The returned logger will use the provided resource bundle for
|
|
* message localization.
|
|
*
|
|
* @implSpec By default, this method calls {@link
|
|
* #getLogger(java.lang.String, java.lang.Module)
|
|
* this.getLogger(name, module)} to obtain a logger, then wraps that
|
|
* logger in a {@link Logger} instance where all methods that do not
|
|
* take a {@link ResourceBundle} as parameter are redirected to one
|
|
* which does - passing the given {@code bundle} for
|
|
* localization. So for instance, a call to {@link
|
|
* Logger#log(Logger.Level, String) Logger.log(Level.INFO, msg)}
|
|
* will end up as a call to {@link
|
|
* Logger#log(Logger.Level, ResourceBundle, String, Object...)
|
|
* Logger.log(Level.INFO, bundle, msg, (Object[])null)} on the wrapped
|
|
* logger instance.
|
|
* Note however that by default, string messages returned by {@link
|
|
* java.util.function.Supplier Supplier<String>} will not be
|
|
* localized, as it is assumed that such strings are messages which are
|
|
* already constructed, rather than keys in a resource bundle.
|
|
* <p>
|
|
* An implementation of {@code LoggerFinder} may override this method,
|
|
* for example, when the underlying logging backend provides its own
|
|
* mechanism for localizing log messages, then such a
|
|
* {@code LoggerFinder} would be free to return a logger
|
|
* that makes direct use of the mechanism provided by the backend.
|
|
*
|
|
* @param name the name of the logger.
|
|
* @param bundle a resource bundle; can be {@code null}.
|
|
* @param module the module for which the logger is being requested.
|
|
* @return an instance of {@link Logger Logger} which will use the
|
|
* provided resource bundle for message localization.
|
|
*
|
|
* @throws NullPointerException if {@code name} is {@code null} or
|
|
* {@code module} is {@code null}.
|
|
* @throws SecurityException if a security manager is present and its
|
|
* {@code checkPermission} method doesn't allow the
|
|
* {@code RuntimePermission("loggerFinder")}.
|
|
*/
|
|
public Logger getLocalizedLogger(String name, ResourceBundle bundle,
|
|
Module module) {
|
|
return new LocalizedLoggerWrapper<>(getLogger(name, module), bundle);
|
|
}
|
|
|
|
/**
|
|
* Returns the {@code LoggerFinder} instance. There is one
|
|
* single system-wide {@code LoggerFinder} instance in
|
|
* the Java Runtime. See the class specification of how the
|
|
* {@link LoggerFinder LoggerFinder} implementation is located and
|
|
* loaded.
|
|
|
|
* @return the {@link LoggerFinder LoggerFinder} instance.
|
|
* @throws SecurityException if a security manager is present and its
|
|
* {@code checkPermission} method doesn't allow the
|
|
* {@code RuntimePermission("loggerFinder")}.
|
|
*/
|
|
public static LoggerFinder getLoggerFinder() {
|
|
final SecurityManager sm = System.getSecurityManager();
|
|
if (sm != null) {
|
|
sm.checkPermission(LOGGERFINDER_PERMISSION);
|
|
}
|
|
return accessProvider();
|
|
}
|
|
|
|
|
|
private static volatile LoggerFinder service;
|
|
static LoggerFinder accessProvider() {
|
|
// We do not need to synchronize: LoggerFinderLoader will
|
|
// always return the same instance, so if we don't have it,
|
|
// just fetch it again.
|
|
if (service == null) {
|
|
PrivilegedAction<LoggerFinder> pa =
|
|
() -> LoggerFinderLoader.getLoggerFinder();
|
|
service = AccessController.doPrivileged(pa, null,
|
|
LOGGERFINDER_PERMISSION);
|
|
}
|
|
return service;
|
|
}
|
|
|
|
}
|
|
|
|
|
|
/**
|
|
* Returns an instance of {@link Logger Logger} for the caller's
|
|
* use.
|
|
*
|
|
* @implSpec
|
|
* Instances returned by this method route messages to loggers
|
|
* obtained by calling {@link LoggerFinder#getLogger(java.lang.String,
|
|
* java.lang.Module) LoggerFinder.getLogger(name, module)}, where
|
|
* {@code module} is the caller's module.
|
|
* In cases where {@code System.getLogger} is called from a context where
|
|
* there is no caller frame on the stack (e.g when called directly
|
|
* from a JNI attached thread), {@code IllegalCallerException} is thrown.
|
|
* To obtain a logger in such a context, use an auxiliary class that will
|
|
* implicitly be identified as the caller, or use the system {@link
|
|
* LoggerFinder#getLoggerFinder() LoggerFinder} to obtain a logger instead.
|
|
* Note that doing the latter may eagerly initialize the underlying
|
|
* logging system.
|
|
*
|
|
* @apiNote
|
|
* This method may defer calling the {@link
|
|
* LoggerFinder#getLogger(java.lang.String, java.lang.Module)
|
|
* LoggerFinder.getLogger} method to create an actual logger supplied by
|
|
* the logging backend, for instance, to allow loggers to be obtained during
|
|
* the system initialization time.
|
|
*
|
|
* @param name the name of the logger.
|
|
* @return an instance of {@link Logger} that can be used by the calling
|
|
* class.
|
|
* @throws NullPointerException if {@code name} is {@code null}.
|
|
* @throws IllegalCallerException if there is no Java caller frame on the
|
|
* stack.
|
|
*
|
|
* @since 9
|
|
*/
|
|
@CallerSensitive
|
|
public static Logger getLogger(String name) {
|
|
Objects.requireNonNull(name);
|
|
final Class<?> caller = Reflection.getCallerClass();
|
|
if (caller == null) {
|
|
throw new IllegalCallerException("no caller frame");
|
|
}
|
|
return LazyLoggers.getLogger(name, caller.getModule());
|
|
}
|
|
|
|
/**
|
|
* Returns a localizable instance of {@link Logger
|
|
* Logger} for the caller's use.
|
|
* The returned logger will use the provided resource bundle for message
|
|
* localization.
|
|
*
|
|
* @implSpec
|
|
* The returned logger will perform message localization as specified
|
|
* by {@link LoggerFinder#getLocalizedLogger(java.lang.String,
|
|
* java.util.ResourceBundle, java.lang.Module)
|
|
* LoggerFinder.getLocalizedLogger(name, bundle, module)}, where
|
|
* {@code module} is the caller's module.
|
|
* In cases where {@code System.getLogger} is called from a context where
|
|
* there is no caller frame on the stack (e.g when called directly
|
|
* from a JNI attached thread), {@code IllegalCallerException} is thrown.
|
|
* To obtain a logger in such a context, use an auxiliary class that
|
|
* will implicitly be identified as the caller, or use the system {@link
|
|
* LoggerFinder#getLoggerFinder() LoggerFinder} to obtain a logger instead.
|
|
* Note that doing the latter may eagerly initialize the underlying
|
|
* logging system.
|
|
*
|
|
* @apiNote
|
|
* This method is intended to be used after the system is fully initialized.
|
|
* This method may trigger the immediate loading and initialization
|
|
* of the {@link LoggerFinder} service, which may cause issues if the
|
|
* Java Runtime is not ready to initialize the concrete service
|
|
* implementation yet.
|
|
* System classes which may be loaded early in the boot sequence and
|
|
* need to log localized messages should create a logger using
|
|
* {@link #getLogger(java.lang.String)} and then use the log methods that
|
|
* take a resource bundle as parameter.
|
|
*
|
|
* @param name the name of the logger.
|
|
* @param bundle a resource bundle.
|
|
* @return an instance of {@link Logger} which will use the provided
|
|
* resource bundle for message localization.
|
|
* @throws NullPointerException if {@code name} is {@code null} or
|
|
* {@code bundle} is {@code null}.
|
|
* @throws IllegalCallerException if there is no Java caller frame on the
|
|
* stack.
|
|
*
|
|
* @since 9
|
|
*/
|
|
@CallerSensitive
|
|
public static Logger getLogger(String name, ResourceBundle bundle) {
|
|
final ResourceBundle rb = Objects.requireNonNull(bundle);
|
|
Objects.requireNonNull(name);
|
|
final Class<?> caller = Reflection.getCallerClass();
|
|
if (caller == null) {
|
|
throw new IllegalCallerException("no caller frame");
|
|
}
|
|
final SecurityManager sm = System.getSecurityManager();
|
|
// We don't use LazyLoggers if a resource bundle is specified.
|
|
// Bootstrap sensitive classes in the JDK do not use resource bundles
|
|
// when logging. This could be revisited later, if it needs to.
|
|
if (sm != null) {
|
|
final PrivilegedAction<Logger> pa =
|
|
() -> LoggerFinder.accessProvider()
|
|
.getLocalizedLogger(name, rb, caller.getModule());
|
|
return AccessController.doPrivileged(pa, null,
|
|
LoggerFinder.LOGGERFINDER_PERMISSION);
|
|
}
|
|
return LoggerFinder.accessProvider()
|
|
.getLocalizedLogger(name, rb, caller.getModule());
|
|
}
|
|
|
|
/**
|
|
* Terminates the currently running Java Virtual Machine. The
|
|
* argument serves as a status code; by convention, a nonzero status
|
|
* code indicates abnormal termination.
|
|
* <p>
|
|
* This method calls the {@code exit} method in class
|
|
* {@code Runtime}. This method never returns normally.
|
|
* <p>
|
|
* The call {@code System.exit(n)} is effectively equivalent to
|
|
* the call:
|
|
* <blockquote><pre>
|
|
* Runtime.getRuntime().exit(n)
|
|
* </pre></blockquote>
|
|
*
|
|
* @param status exit status.
|
|
* @throws SecurityException
|
|
* if a security manager exists and its {@code checkExit}
|
|
* method doesn't allow exit with the specified status.
|
|
* @see java.lang.Runtime#exit(int)
|
|
*/
|
|
public static void exit(int status) {
|
|
Runtime.getRuntime().exit(status);
|
|
}
|
|
|
|
/**
|
|
* Runs the garbage collector in the Java Virtual Machine.
|
|
* <p>
|
|
* Calling the {@code gc} method suggests that the Java Virtual Machine
|
|
* expend effort toward recycling unused objects in order to
|
|
* make the memory they currently occupy available for reuse
|
|
* by the Java Virtual Machine.
|
|
* When control returns from the method call, the Java Virtual Machine
|
|
* has made a best effort to reclaim space from all unused objects.
|
|
* There is no guarantee that this effort will recycle any particular
|
|
* number of unused objects, reclaim any particular amount of space, or
|
|
* complete at any particular time, if at all, before the method returns or ever.
|
|
* <p>
|
|
* The call {@code System.gc()} is effectively equivalent to the
|
|
* call:
|
|
* <blockquote><pre>
|
|
* Runtime.getRuntime().gc()
|
|
* </pre></blockquote>
|
|
*
|
|
* @see java.lang.Runtime#gc()
|
|
*/
|
|
public static void gc() {
|
|
Runtime.getRuntime().gc();
|
|
}
|
|
|
|
/**
|
|
* Runs the finalization methods of any objects pending finalization.
|
|
*
|
|
* Calling this method suggests that the Java Virtual Machine expend
|
|
* effort toward running the {@code finalize} methods of objects
|
|
* that have been found to be discarded but whose {@code finalize}
|
|
* methods have not yet been run. When control returns from the
|
|
* method call, the Java Virtual Machine has made a best effort to
|
|
* complete all outstanding finalizations.
|
|
* <p>
|
|
* The call {@code System.runFinalization()} is effectively
|
|
* equivalent to the call:
|
|
* <blockquote><pre>
|
|
* Runtime.getRuntime().runFinalization()
|
|
* </pre></blockquote>
|
|
*
|
|
* @see java.lang.Runtime#runFinalization()
|
|
*/
|
|
public static void runFinalization() {
|
|
Runtime.getRuntime().runFinalization();
|
|
}
|
|
|
|
/**
|
|
* Loads the native library specified by the filename argument. The filename
|
|
* argument must be an absolute path name.
|
|
*
|
|
* If the filename argument, when stripped of any platform-specific library
|
|
* prefix, path, and file extension, indicates a library whose name is,
|
|
* for example, L, and a native library called L is statically linked
|
|
* with the VM, then the JNI_OnLoad_L function exported by the library
|
|
* is invoked rather than attempting to load a dynamic library.
|
|
* A filename matching the argument does not have to exist in the
|
|
* file system.
|
|
* See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
|
|
* for more details.
|
|
*
|
|
* Otherwise, the filename argument is mapped to a native library image in
|
|
* an implementation-dependent manner.
|
|
*
|
|
* <p>
|
|
* The call {@code System.load(name)} is effectively equivalent
|
|
* to the call:
|
|
* <blockquote><pre>
|
|
* Runtime.getRuntime().load(name)
|
|
* </pre></blockquote>
|
|
*
|
|
* @param filename the file to load.
|
|
* @throws SecurityException if a security manager exists and its
|
|
* {@code checkLink} method doesn't allow
|
|
* loading of the specified dynamic library
|
|
* @throws UnsatisfiedLinkError if either the filename is not an
|
|
* absolute path name, the native library is not statically
|
|
* linked with the VM, or the library cannot be mapped to
|
|
* a native library image by the host system.
|
|
* @throws NullPointerException if {@code filename} is {@code null}
|
|
* @see java.lang.Runtime#load(java.lang.String)
|
|
* @see java.lang.SecurityManager#checkLink(java.lang.String)
|
|
*/
|
|
@CallerSensitive
|
|
public static void load(String filename) {
|
|
Runtime.getRuntime().load0(Reflection.getCallerClass(), filename);
|
|
}
|
|
|
|
/**
|
|
* Loads the native library specified by the {@code libname}
|
|
* argument. The {@code libname} argument must not contain any platform
|
|
* specific prefix, file extension or path. If a native library
|
|
* called {@code libname} is statically linked with the VM, then the
|
|
* JNI_OnLoad_{@code libname} function exported by the library is invoked.
|
|
* See the <a href="{@docRoot}/../specs/jni/index.html"> JNI Specification</a>
|
|
* for more details.
|
|
*
|
|
* Otherwise, the libname argument is loaded from a system library
|
|
* location and mapped to a native library image in an implementation-
|
|
* dependent manner.
|
|
* <p>
|
|
* The call {@code System.loadLibrary(name)} is effectively
|
|
* equivalent to the call
|
|
* <blockquote><pre>
|
|
* Runtime.getRuntime().loadLibrary(name)
|
|
* </pre></blockquote>
|
|
*
|
|
* @param libname the name of the library.
|
|
* @throws SecurityException if a security manager exists and its
|
|
* {@code checkLink} method doesn't allow
|
|
* loading of the specified dynamic library
|
|
* @throws UnsatisfiedLinkError if either the libname argument
|
|
* contains a file path, the native library is not statically
|
|
* linked with the VM, or the library cannot be mapped to a
|
|
* native library image by the host system.
|
|
* @throws NullPointerException if {@code libname} is {@code null}
|
|
* @see java.lang.Runtime#loadLibrary(java.lang.String)
|
|
* @see java.lang.SecurityManager#checkLink(java.lang.String)
|
|
*/
|
|
@CallerSensitive
|
|
public static void loadLibrary(String libname) {
|
|
Runtime.getRuntime().loadLibrary0(Reflection.getCallerClass(), libname);
|
|
}
|
|
|
|
/**
|
|
* Maps a library name into a platform-specific string representing
|
|
* a native library.
|
|
*
|
|
* @param libname the name of the library.
|
|
* @return a platform-dependent native library name.
|
|
* @throws NullPointerException if {@code libname} is {@code null}
|
|
* @see java.lang.System#loadLibrary(java.lang.String)
|
|
* @see java.lang.ClassLoader#findLibrary(java.lang.String)
|
|
* @since 1.2
|
|
*/
|
|
public static native String mapLibraryName(String libname);
|
|
|
|
/**
|
|
* Create PrintStream for stdout/err based on encoding.
|
|
*/
|
|
private static PrintStream newPrintStream(FileOutputStream fos, String enc) {
|
|
if (enc != null) {
|
|
try {
|
|
return new PrintStream(new BufferedOutputStream(fos, 128), true, enc);
|
|
} catch (UnsupportedEncodingException uee) {}
|
|
}
|
|
return new PrintStream(new BufferedOutputStream(fos, 128), true);
|
|
}
|
|
|
|
/**
|
|
* Logs an exception/error at initialization time to stdout or stderr.
|
|
*
|
|
* @param printToStderr to print to stderr rather than stdout
|
|
* @param printStackTrace to print the stack trace
|
|
* @param msg the message to print before the exception, can be {@code null}
|
|
* @param e the exception or error
|
|
*/
|
|
private static void logInitException(boolean printToStderr,
|
|
boolean printStackTrace,
|
|
String msg,
|
|
Throwable e) {
|
|
if (VM.initLevel() < 1) {
|
|
throw new InternalError("system classes not initialized");
|
|
}
|
|
PrintStream log = (printToStderr) ? err : out;
|
|
if (msg != null) {
|
|
log.println(msg);
|
|
}
|
|
if (printStackTrace) {
|
|
e.printStackTrace(log);
|
|
} else {
|
|
log.println(e);
|
|
for (Throwable suppressed : e.getSuppressed()) {
|
|
log.println("Suppressed: " + suppressed);
|
|
}
|
|
Throwable cause = e.getCause();
|
|
if (cause != null) {
|
|
log.println("Caused by: " + cause);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Create the Properties object from a map - masking out system properties
|
|
* that are not intended for public access.
|
|
*/
|
|
private static Properties createProperties(Map<String, String> initialProps) {
|
|
Properties properties = new Properties(initialProps.size());
|
|
for (var entry : initialProps.entrySet()) {
|
|
String prop = entry.getKey();
|
|
switch (prop) {
|
|
// Do not add private system properties to the Properties
|
|
case "sun.nio.MaxDirectMemorySize":
|
|
case "sun.nio.PageAlignDirectMemory":
|
|
// used by java.lang.Integer.IntegerCache
|
|
case "java.lang.Integer.IntegerCache.high":
|
|
// used by sun.launcher.LauncherHelper
|
|
case "sun.java.launcher.diag":
|
|
// used by jdk.internal.loader.ClassLoaders
|
|
case "jdk.boot.class.path.append":
|
|
break;
|
|
default:
|
|
properties.put(prop, entry.getValue());
|
|
}
|
|
}
|
|
return properties;
|
|
}
|
|
|
|
/**
|
|
* Initialize the system class. Called after thread initialization.
|
|
*/
|
|
private static void initPhase1() {
|
|
// VM might invoke JNU_NewStringPlatform() to set those encoding
|
|
// sensitive properties (user.home, user.name, boot.class.path, etc.)
|
|
// during "props" initialization.
|
|
// The charset is initialized in System.c and does not depend on the Properties.
|
|
Map<String, String> tempProps = SystemProps.initProperties();
|
|
VersionProps.init(tempProps);
|
|
|
|
// There are certain system configurations that may be controlled by
|
|
// VM options such as the maximum amount of direct memory and
|
|
// Integer cache size used to support the object identity semantics
|
|
// of autoboxing. Typically, the library will obtain these values
|
|
// from the properties set by the VM. If the properties are for
|
|
// internal implementation use only, these properties should be
|
|
// masked from the system properties.
|
|
//
|
|
// Save a private copy of the system properties object that
|
|
// can only be accessed by the internal implementation.
|
|
VM.saveProperties(tempProps);
|
|
props = createProperties(tempProps);
|
|
|
|
StaticProperty.javaHome(); // Load StaticProperty to cache the property values
|
|
|
|
lineSeparator = props.getProperty("line.separator");
|
|
|
|
FileInputStream fdIn = new FileInputStream(FileDescriptor.in);
|
|
FileOutputStream fdOut = new FileOutputStream(FileDescriptor.out);
|
|
FileOutputStream fdErr = new FileOutputStream(FileDescriptor.err);
|
|
setIn0(new BufferedInputStream(fdIn));
|
|
setOut0(newPrintStream(fdOut, props.getProperty("sun.stdout.encoding")));
|
|
setErr0(newPrintStream(fdErr, props.getProperty("sun.stderr.encoding")));
|
|
|
|
// Setup Java signal handlers for HUP, TERM, and INT (where available).
|
|
Terminator.setup();
|
|
|
|
// Initialize any miscellaneous operating system settings that need to be
|
|
// set for the class libraries. Currently this is no-op everywhere except
|
|
// for Windows where the process-wide error mode is set before the java.io
|
|
// classes are used.
|
|
VM.initializeOSEnvironment();
|
|
|
|
// The main thread is not added to its thread group in the same
|
|
// way as other threads; we must do it ourselves here.
|
|
Thread current = Thread.currentThread();
|
|
current.getThreadGroup().add(current);
|
|
|
|
// register shared secrets
|
|
setJavaLangAccess();
|
|
|
|
ClassLoader.initLibraryPaths();
|
|
|
|
// Subsystems that are invoked during initialization can invoke
|
|
// VM.isBooted() in order to avoid doing things that should
|
|
// wait until the VM is fully initialized. The initialization level
|
|
// is incremented from 0 to 1 here to indicate the first phase of
|
|
// initialization has completed.
|
|
// IMPORTANT: Ensure that this remains the last initialization action!
|
|
VM.initLevel(1);
|
|
}
|
|
|
|
// @see #initPhase2()
|
|
static ModuleLayer bootLayer;
|
|
|
|
/*
|
|
* Invoked by VM. Phase 2 module system initialization.
|
|
* Only classes in java.base can be loaded in this phase.
|
|
*
|
|
* @param printToStderr print exceptions to stderr rather than stdout
|
|
* @param printStackTrace print stack trace when exception occurs
|
|
*
|
|
* @return JNI_OK for success, JNI_ERR for failure
|
|
*/
|
|
private static int initPhase2(boolean printToStderr, boolean printStackTrace) {
|
|
try {
|
|
bootLayer = ModuleBootstrap.boot();
|
|
} catch (Exception | Error e) {
|
|
logInitException(printToStderr, printStackTrace,
|
|
"Error occurred during initialization of boot layer", e);
|
|
return -1; // JNI_ERR
|
|
}
|
|
|
|
// module system initialized
|
|
VM.initLevel(2);
|
|
|
|
return 0; // JNI_OK
|
|
}
|
|
|
|
/*
|
|
* Invoked by VM. Phase 3 is the final system initialization:
|
|
* 1. set security manager
|
|
* 2. set system class loader
|
|
* 3. set TCCL
|
|
*
|
|
* This method must be called after the module system initialization.
|
|
* The security manager and system class loader may be a custom class from
|
|
* the application classpath or modulepath.
|
|
*/
|
|
private static void initPhase3() {
|
|
String smProp = System.getProperty("java.security.manager");
|
|
if (smProp != null) {
|
|
switch (smProp) {
|
|
case "disallow":
|
|
allowSecurityManager = NEVER;
|
|
break;
|
|
case "allow":
|
|
allowSecurityManager = MAYBE;
|
|
break;
|
|
case "":
|
|
case "default":
|
|
setSecurityManager(new SecurityManager());
|
|
allowSecurityManager = MAYBE;
|
|
break;
|
|
default:
|
|
try {
|
|
ClassLoader cl = ClassLoader.getBuiltinAppClassLoader();
|
|
Class<?> c = Class.forName(smProp, false, cl);
|
|
Constructor<?> ctor = c.getConstructor();
|
|
// Must be a public subclass of SecurityManager with
|
|
// a public no-arg constructor
|
|
if (!SecurityManager.class.isAssignableFrom(c) ||
|
|
!Modifier.isPublic(c.getModifiers()) ||
|
|
!Modifier.isPublic(ctor.getModifiers())) {
|
|
throw new Error("Could not create SecurityManager: "
|
|
+ ctor.toString());
|
|
}
|
|
// custom security manager may be in non-exported package
|
|
ctor.setAccessible(true);
|
|
SecurityManager sm = (SecurityManager) ctor.newInstance();
|
|
setSecurityManager(sm);
|
|
} catch (Exception e) {
|
|
throw new InternalError("Could not create SecurityManager", e);
|
|
}
|
|
allowSecurityManager = MAYBE;
|
|
}
|
|
} else {
|
|
allowSecurityManager = MAYBE;
|
|
}
|
|
|
|
// initializing the system class loader
|
|
VM.initLevel(3);
|
|
|
|
// system class loader initialized
|
|
ClassLoader scl = ClassLoader.initSystemClassLoader();
|
|
|
|
// set TCCL
|
|
Thread.currentThread().setContextClassLoader(scl);
|
|
|
|
// system is fully initialized
|
|
VM.initLevel(4);
|
|
}
|
|
|
|
private static void setJavaLangAccess() {
|
|
// Allow privileged classes outside of java.lang
|
|
SharedSecrets.setJavaLangAccess(new JavaLangAccess() {
|
|
public List<Method> getDeclaredPublicMethods(Class<?> klass, String name, Class<?>... parameterTypes) {
|
|
return klass.getDeclaredPublicMethods(name, parameterTypes);
|
|
}
|
|
public jdk.internal.reflect.ConstantPool getConstantPool(Class<?> klass) {
|
|
return klass.getConstantPool();
|
|
}
|
|
public boolean casAnnotationType(Class<?> klass, AnnotationType oldType, AnnotationType newType) {
|
|
return klass.casAnnotationType(oldType, newType);
|
|
}
|
|
public AnnotationType getAnnotationType(Class<?> klass) {
|
|
return klass.getAnnotationType();
|
|
}
|
|
public Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap(Class<?> klass) {
|
|
return klass.getDeclaredAnnotationMap();
|
|
}
|
|
public byte[] getRawClassAnnotations(Class<?> klass) {
|
|
return klass.getRawAnnotations();
|
|
}
|
|
public byte[] getRawClassTypeAnnotations(Class<?> klass) {
|
|
return klass.getRawTypeAnnotations();
|
|
}
|
|
public byte[] getRawExecutableTypeAnnotations(Executable executable) {
|
|
return Class.getExecutableTypeAnnotationBytes(executable);
|
|
}
|
|
public <E extends Enum<E>>
|
|
E[] getEnumConstantsShared(Class<E> klass) {
|
|
return klass.getEnumConstantsShared();
|
|
}
|
|
public void blockedOn(Interruptible b) {
|
|
Thread.blockedOn(b);
|
|
}
|
|
public void registerShutdownHook(int slot, boolean registerShutdownInProgress, Runnable hook) {
|
|
Shutdown.add(slot, registerShutdownInProgress, hook);
|
|
}
|
|
public Thread newThreadWithAcc(Runnable target, AccessControlContext acc) {
|
|
return new Thread(target, acc);
|
|
}
|
|
@SuppressWarnings("deprecation")
|
|
public void invokeFinalize(Object o) throws Throwable {
|
|
o.finalize();
|
|
}
|
|
public ConcurrentHashMap<?, ?> createOrGetClassLoaderValueMap(ClassLoader cl) {
|
|
return cl.createOrGetClassLoaderValueMap();
|
|
}
|
|
public Class<?> defineClass(ClassLoader loader, String name, byte[] b, ProtectionDomain pd, String source) {
|
|
return ClassLoader.defineClass1(loader, name, b, 0, b.length, pd, source);
|
|
}
|
|
public Class<?> findBootstrapClassOrNull(ClassLoader cl, String name) {
|
|
return cl.findBootstrapClassOrNull(name);
|
|
}
|
|
public Package definePackage(ClassLoader cl, String name, Module module) {
|
|
return cl.definePackage(name, module);
|
|
}
|
|
public String fastUUID(long lsb, long msb) {
|
|
return Long.fastUUID(lsb, msb);
|
|
}
|
|
public void addNonExportedPackages(ModuleLayer layer) {
|
|
SecurityManager.addNonExportedPackages(layer);
|
|
}
|
|
public void invalidatePackageAccessCache() {
|
|
SecurityManager.invalidatePackageAccessCache();
|
|
}
|
|
public Module defineModule(ClassLoader loader,
|
|
ModuleDescriptor descriptor,
|
|
URI uri) {
|
|
return new Module(null, loader, descriptor, uri);
|
|
}
|
|
public Module defineUnnamedModule(ClassLoader loader) {
|
|
return new Module(loader);
|
|
}
|
|
public void addReads(Module m1, Module m2) {
|
|
m1.implAddReads(m2);
|
|
}
|
|
public void addReadsAllUnnamed(Module m) {
|
|
m.implAddReadsAllUnnamed();
|
|
}
|
|
public void addExports(Module m, String pn, Module other) {
|
|
m.implAddExports(pn, other);
|
|
}
|
|
public void addExportsToAllUnnamed(Module m, String pn) {
|
|
m.implAddExportsToAllUnnamed(pn);
|
|
}
|
|
public void addOpens(Module m, String pn, Module other) {
|
|
m.implAddOpens(pn, other);
|
|
}
|
|
public void addOpensToAllUnnamed(Module m, String pn) {
|
|
m.implAddOpensToAllUnnamed(pn);
|
|
}
|
|
public void addOpensToAllUnnamed(Module m, Iterator<String> packages) {
|
|
m.implAddOpensToAllUnnamed(packages);
|
|
}
|
|
public void addUses(Module m, Class<?> service) {
|
|
m.implAddUses(service);
|
|
}
|
|
public boolean isReflectivelyExported(Module m, String pn, Module other) {
|
|
return m.isReflectivelyExported(pn, other);
|
|
}
|
|
public boolean isReflectivelyOpened(Module m, String pn, Module other) {
|
|
return m.isReflectivelyOpened(pn, other);
|
|
}
|
|
public ServicesCatalog getServicesCatalog(ModuleLayer layer) {
|
|
return layer.getServicesCatalog();
|
|
}
|
|
public Stream<ModuleLayer> layers(ModuleLayer layer) {
|
|
return layer.layers();
|
|
}
|
|
public Stream<ModuleLayer> layers(ClassLoader loader) {
|
|
return ModuleLayer.layers(loader);
|
|
}
|
|
|
|
public String newStringNoRepl(byte[] bytes, Charset cs) throws CharacterCodingException {
|
|
return StringCoding.newStringNoRepl(bytes, cs);
|
|
}
|
|
|
|
public byte[] getBytesNoRepl(String s, Charset cs) throws CharacterCodingException {
|
|
return StringCoding.getBytesNoRepl(s, cs);
|
|
}
|
|
|
|
public String newStringUTF8NoRepl(byte[] bytes, int off, int len) {
|
|
return StringCoding.newStringUTF8NoRepl(bytes, off, len);
|
|
}
|
|
|
|
public byte[] getBytesUTF8NoRepl(String s) {
|
|
return StringCoding.getBytesUTF8NoRepl(s);
|
|
}
|
|
|
|
public void setCause(Throwable t, Throwable cause) {
|
|
t.setCause(cause);
|
|
}
|
|
|
|
public void loadLibrary(Class<?> caller, String library) {
|
|
assert library.indexOf(java.io.File.separatorChar) < 0;
|
|
ClassLoader.loadLibrary(caller, library, false);
|
|
}
|
|
});
|
|
}
|
|
}
|