8231632: HttpURLConnection::usingProxy could specify that it may lazily evaluate the fact

Modified method description to disambiguate when false is returned and altered implementation

Reviewed-by: dfuchs, chegar, vtewari

src/java.base/share/classes/java/net/HttpURLConnection.java

@@ -618,8 +618,13 @@ public abstract class HttpURLConnection extends URLConnection {
 
     /**
      * Indicates if the connection is going through a proxy.
-     * @return a boolean indicating if the connection is
+     *
-     * using a proxy.
+     * This method returns {@code true} if the connection is known
+     * to be going or has gone through proxies, and returns {@code false}
+     * if the connection will never go through a proxy or if
+     * the use of a proxy cannot be determined.
+     *
+     * @return a boolean indicating if the connection is using a proxy.
      */
     public abstract boolean usingProxy();
 

src/java.base/share/classes/sun/net/www/protocol/http/HttpURLConnection.java

@@ -312,6 +312,8 @@ public class HttpURLConnection extends java.net.HttpURLConnection {
     private CookieHandler cookieHandler;
     private final ResponseCache cacheHandler;
 
+    private volatile boolean usingProxy;
+
     // the cached response, and cached response headers and body
     protected CacheResponse cachedResponse;
     private MessageHeader cachedHeaders;
@@ -320,7 +322,6 @@ public class HttpURLConnection extends java.net.HttpURLConnection {
     /* output stream to server */
     protected PrintStream ps = null;
 
-
     /* buffered error stream */
     private InputStream errorStream = null;
 
@@ -1240,6 +1241,7 @@ public class HttpURLConnection extends java.net.HttpURLConnection {
                 }
             }
 
+            usingProxy = usingProxy || usingProxyInternal();
             ps = (PrintStream)http.getOutputStream();
         } catch (IOException e) {
             throw e;
@@ -2917,7 +2919,7 @@ public class HttpURLConnection extends java.net.HttpURLConnection {
      * closed the connection to the web server.
      */
     private void disconnectWeb() throws IOException {
-        if (usingProxy() && http.isKeepingAlive()) {
+        if (usingProxyInternal() && http.isKeepingAlive()) {
             responseCode = -1;
             // clean up, particularly, skip the content part
             // of a 401 error response
@@ -3020,13 +3022,31 @@ public class HttpURLConnection extends java.net.HttpURLConnection {
         }
     }
 
-    public boolean usingProxy() {
+    /**
+     * Returns true only if the established connection is using a proxy
+     */
+    boolean usingProxyInternal() {
         if (http != null) {
             return (http.getProxyHostUsed() != null);
         }
         return false;
     }
 
+    /**
+     * Returns true if the established connection is using a proxy
+     * or if a proxy is specified for the inactive connection
+     */
+    @Override
+    public boolean usingProxy() {
+        if (usingProxy || usingProxyInternal())
+            return true;
+
+        if (instProxy != null)
+            return instProxy.type().equals(Proxy.Type.HTTP);
+
+        return false;
+    }
+
     // constant strings represent set-cookie header names
     private static final String SET_COOKIE = "set-cookie";
     private static final String SET_COOKIE2 = "set-cookie2";

test/jdk/java/net/HttpURLConnection/HttpURLConnUsingProxy.java

@@ -0,0 +1,335 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/* @test
+ * @bug 8231632
+ * @summary HttpURLConnection::usingProxy could specify that it lazily evaluates the fact
+ * @modules java.base/sun.net.www
+ * @library /test/lib
+ * @run main/othervm HttpURLConnUsingProxy
+ */
+
+import java.io.*;
+import java.net.*;
+import java.nio.charset.StandardCharsets;
+
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpHandler;
+import com.sun.net.httpserver.HttpServer;
+import jdk.test.lib.net.URIBuilder;
+
+public class HttpURLConnUsingProxy {
+    static HttpServer server;
+    static Proxy proxy;
+    static InetSocketAddress isa;
+
+    static class Handler implements HttpHandler {
+
+        @Override
+        public void handle(HttpExchange exchange) throws IOException {
+            byte[] response = "Hello World!".getBytes(StandardCharsets.UTF_8);
+            try (InputStream req = exchange.getRequestBody()) {
+                req.readAllBytes();
+            }
+            exchange.sendResponseHeaders(200, response.length);
+            try (OutputStream resp = exchange.getResponseBody()) {
+                resp.write(response);
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        try {
+            InetAddress loopbackAddress = InetAddress.getLoopbackAddress();
+            InetSocketAddress addr = new InetSocketAddress(loopbackAddress, 0);
+            server = HttpServer.create(addr, 0);
+            server.createContext("/HttpURLConnUsingProxy/http1/", new Handler());
+            server.start();
+
+            ProxyServer pserver = new ProxyServer(loopbackAddress,
+                    server.getAddress().getPort());
+            // Start proxy server
+            new Thread(pserver).start();
+
+            URL url = URIBuilder.newBuilder()
+                    .scheme("http")
+                    .loopback()
+                    .port(server.getAddress().getPort())
+                    .path("/HttpURLConnUsingProxy/http1/x.html")
+                    .toURLUnchecked();
+
+            // NO_PROXY
+            try {
+                HttpURLConnection urlc =
+                        (HttpURLConnection) url.openConnection(Proxy.NO_PROXY);
+                assertEqual(urlc.usingProxy(), false);
+                urlc.getResponseCode();
+                assertEqual(urlc.usingProxy(), false);
+                urlc.disconnect();
+            } catch (IOException ioe) {
+                throw new RuntimeException("Direct connection should succeed: "
+                        + ioe.getMessage());
+            }
+
+            // Non-existing proxy
+            try {
+                isa = InetSocketAddress.createUnresolved("inexistent", 8080);
+                proxy = new Proxy(Proxy.Type.HTTP, isa);
+                HttpURLConnection urlc = (HttpURLConnection) url.openConnection(proxy);
+                assertEqual(urlc.usingProxy(), true);
+                InputStream is = urlc.getInputStream();
+                is.close();
+                throw new RuntimeException("Non-existing proxy should cause IOException");
+            } catch (IOException ioe) {
+                // expected
+            }
+
+            // Normal proxy settings
+            try {
+                isa = InetSocketAddress.createUnresolved(loopbackAddress.getHostAddress(),
+                        pserver.getPort());
+                proxy = new Proxy(Proxy.Type.HTTP, isa);
+                HttpURLConnection urlc = (HttpURLConnection) url.openConnection(proxy);
+                assertEqual(urlc.usingProxy(), true);
+                urlc.getResponseCode();
+                assertEqual(urlc.usingProxy(), true);
+                urlc.disconnect();
+            } catch (IOException ioe) {
+                throw new RuntimeException("Connection through local proxy should succeed: "
+                        + ioe.getMessage());
+            }
+
+            // Reuse proxy with new HttpURLConnection
+            try {
+                HttpURLConnection urlc = (HttpURLConnection) url.openConnection(proxy);
+                assertEqual(urlc.usingProxy(), true);
+                urlc.getResponseCode();
+                assertEqual(urlc.usingProxy(), true);
+                read(urlc.getInputStream());
+                assertEqual(urlc.usingProxy(), true);
+            } catch (IOException ioe) {
+                throw new RuntimeException("Connection through local proxy should succeed: "
+                        + ioe.getMessage());
+            }
+
+            // Reuse proxy with existing HttpURLConnection
+            try {
+                HttpURLConnection urlc = (HttpURLConnection) url.openConnection(proxy);
+                assertEqual(urlc.usingProxy(), true);
+                urlc.getResponseCode();
+                assertEqual(urlc.usingProxy(), true);
+                read(urlc.getInputStream());
+                assertEqual(urlc.usingProxy(), true);
+                urlc.disconnect();
+            } catch (IOException ioe) {
+                throw new RuntimeException("Connection through local proxy should succeed: "
+                        + ioe.getMessage());
+            }
+
+            // ProxySelector with normal proxy settings
+            try {
+                ProxySelector.setDefault(ProxySelector.of(isa));
+                HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
+                assertEqual(urlc.usingProxy(), false);
+                urlc.getResponseCode();
+                assertEqual(urlc.usingProxy(), true);
+                read(urlc.getInputStream());
+                assertEqual(urlc.usingProxy(), true);
+                urlc.disconnect();
+                assertEqual(urlc.usingProxy(), true);
+            } catch (IOException ioe) {
+                throw new RuntimeException("Connection through local proxy should succeed: "
+                        + ioe.getMessage());
+            }
+
+            // ProxySelector with proxying disabled
+            try {
+                ProxySelector.setDefault(ProxySelector.of(null));
+                HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
+                assertEqual(urlc.usingProxy(), false);
+                urlc.getResponseCode();
+                assertEqual(urlc.usingProxy(), false);
+                read(urlc.getInputStream());
+                assertEqual(urlc.usingProxy(), false);
+            } catch (IOException ioe) {
+                throw new RuntimeException("Direct connection should succeed: "
+                        + ioe.getMessage());
+            }
+
+            // ProxySelector overwritten
+            try {
+                ProxySelector.setDefault(ProxySelector.of(isa));
+                HttpURLConnection urlc = (HttpURLConnection) url.openConnection(Proxy.NO_PROXY);
+                assertEqual(urlc.usingProxy(), false);
+                urlc.disconnect();
+            } catch (IOException ioe) {
+                throw new RuntimeException("Direct connection should succeed: "
+                        + ioe.getMessage());
+            }
+
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        } finally {
+            if (server != null) {
+                server.stop(0);
+            }
+        }
+    }
+
+    static class ProxyServer extends Thread {
+        private static ServerSocket ss = null;
+
+        // Client requesting a tunnel
+        private Socket clientSocket = null;
+
+        /*
+         * Origin server's address and port that the client
+         * wants to establish the tunnel for communication.
+         */
+        private InetAddress serverInetAddr;
+        private int serverPort;
+
+        public ProxyServer(InetAddress server, int port) throws IOException {
+            serverInetAddr = server;
+            serverPort = port;
+            ss = new ServerSocket(0, 0, InetAddress.getLoopbackAddress());
+        }
+
+        public void run() {
+            while (true) {
+                try {
+                    clientSocket = ss.accept();
+                    processRequests();
+                } catch (Exception e) {
+                    System.out.println("Proxy failed: " + e);
+                    e.printStackTrace();
+                    try {
+                        ss.close();
+                    } catch (IOException ioe) {
+                        System.out.println("ProxyServer close error: " + ioe);
+                        ioe.printStackTrace();
+                    }
+                }
+            }
+        }
+
+        private void processRequests() throws Exception {
+            // Connection set to tunneling mode
+
+            Socket serverSocket = new Socket(serverInetAddr, serverPort);
+            ProxyTunnel clientToServer = new ProxyTunnel(
+                    clientSocket, serverSocket);
+            ProxyTunnel serverToClient = new ProxyTunnel(
+                    serverSocket, clientSocket);
+            clientToServer.start();
+            serverToClient.start();
+            System.out.println("Proxy: Started tunneling...");
+
+            clientToServer.join();
+            serverToClient.join();
+            System.out.println("Proxy: Finished tunneling...");
+
+            clientToServer.close();
+            serverToClient.close();
+        }
+
+        /**
+         * **************************************************************
+         * Helper methods follow
+         * **************************************************************
+         */
+        public int getPort() {
+            return ss.getLocalPort();
+        }
+
+        /*
+         * This inner class provides unidirectional data flow through the sockets
+         * by continuously copying bytes from input socket to output socket
+         * while both sockets are open and EOF has not been received.
+         */
+        static class ProxyTunnel extends Thread {
+            Socket sockIn;
+            Socket sockOut;
+            InputStream input;
+            OutputStream output;
+
+            public ProxyTunnel(Socket sockIn, Socket sockOut) throws Exception {
+                this.sockIn = sockIn;
+                this.sockOut = sockOut;
+                input = sockIn.getInputStream();
+                output = sockOut.getOutputStream();
+            }
+
+            public void run() {
+                int BUFFER_SIZE = 400;
+                byte[] buf = new byte[BUFFER_SIZE];
+                int bytesRead = 0;
+                int count = 0;    // Keep track of amount of data transferred
+
+                try {
+                    while ((bytesRead = input.read(buf)) >= 0) {
+                        output.write(buf, 0, bytesRead);
+                        output.flush();
+                        count += bytesRead;
+                    }
+                } catch (IOException e) {
+                    /*
+                     * Peer end has closed connection
+                     * so we close tunnel
+                     */
+                    close();
+                }
+            }
+
+            public void close() {
+                try {
+                    if (!sockIn.isClosed())
+                        sockIn.close();
+                    if (!sockOut.isClosed())
+                        sockOut.close();
+                } catch (IOException ignored) {
+                }
+            }
+        }
+    }
+
+    private static void assertEqual(boolean usingProxy, boolean expected) {
+        if (usingProxy != expected) {
+            throw new RuntimeException("Expected: " + expected
+                    + " but usingProxy returned: " + usingProxy);
+        }
+    }
+
+    private static String read(InputStream inputStream) throws IOException {
+        StringBuilder sb = new StringBuilder();
+        BufferedReader bufferedReader = new BufferedReader(
+                new InputStreamReader(inputStream, StandardCharsets.UTF_8));
+        int i = bufferedReader.read();
+        while (i != -1) {
+            sb.append((char) i);
+            i = bufferedReader.read();
+        }
+        bufferedReader.close();
+        return sb.toString();
+    }
+}