Eirik Bjørsnøs 8e8f800071 8344943: Mark not subclassable classes final in java.base exported classes
Reviewed-by: weijun, liach, djelinski
2025-01-24 19:29:05 +00:00

329 lines
13 KiB
Java

/*
* Copyright (c) 1995, 2025, 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* 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.
*/
package java.net;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.util.BitSet;
import java.util.Objects;
import java.util.HexFormat;
import java.util.function.IntPredicate;
import jdk.internal.util.ImmutableBitSetPredicate;
/**
* Utility class for HTML form encoding. This class contains static methods
* for converting a String to the <CODE>application/x-www-form-urlencoded</CODE> MIME
* format. For more information about HTML form encoding, consult the HTML
* <A HREF="http://www.w3.org/TR/html4/">specification</A>.
*
* <p>
* When encoding a String, the following rules apply:
*
* <ul>
* <li>The alphanumeric characters &quot;{@code a}&quot; through
* &quot;{@code z}&quot;, &quot;{@code A}&quot; through
* &quot;{@code Z}&quot; and &quot;{@code 0}&quot;
* through &quot;{@code 9}&quot; remain the same.
* <li>The special characters &quot;{@code .}&quot;,
* &quot;{@code -}&quot;, &quot;{@code *}&quot;, and
* &quot;{@code _}&quot; remain the same.
* <li>The space character &quot; &nbsp; &quot; is
* converted into a plus sign &quot;{@code +}&quot;.
* <li>All other characters are unsafe and are first converted into
* one or more bytes using some encoding scheme. Then each byte is
* represented by the 3-character string
* &quot;<i>{@code %xy}</i>&quot;, where <i>xy</i> is the
* two-digit hexadecimal representation of the byte.
* The recommended encoding scheme to use is UTF-8. However,
* for compatibility reasons, if an encoding is not specified,
* then the default charset is used.
* </ul>
*
* <p>
* For example using UTF-8 as the encoding scheme the string &quot;The
* string &#252;@foo-bar&quot; would get converted to
* &quot;The+string+%C3%BC%40foo-bar&quot; because in UTF-8 the character
* &#252; is encoded as two bytes C3 (hex) and BC (hex), and the
* character @ is encoded as one byte 40 (hex).
*
* @spec https://www.w3.org/TR/html4 HTML 4.01 Specification
* @see Charset#defaultCharset()
*
* @author Herb Jellinek
* @since 1.0
*/
public final class URLEncoder {
private static final IntPredicate DONT_NEED_ENCODING;
static {
/* The list of characters that are not encoded has been
* determined as follows:
*
* RFC 2396 states:
* -----
* Data characters that are allowed in a URI but do not have a
* reserved purpose are called unreserved. These include upper
* and lower case letters, decimal digits, and a limited set of
* punctuation marks and symbols.
*
* unreserved = alphanum | mark
*
* mark = "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
*
* Unreserved characters can be escaped without changing the
* semantics of the URI, but this should not be done unless the
* URI is being used in a context that does not allow the
* unescaped character to appear.
* -----
*
* It appears that both Netscape and Internet Explorer escape
* all special characters from this list with the exception
* of "-", "_", ".", "*". While it is not clear why they are
* escaping the other characters, perhaps it is safest to
* assume that there might be contexts in which the others
* are unsafe if not escaped. Therefore, we will use the same
* list. It is also noteworthy that this is consistent with
* O'Reilly's "HTML: The Definitive Guide" (page 164).
*
* As a last note, Internet Explorer does not encode the "@"
* character which is clearly not unreserved according to the
* RFC. We are being consistent with the RFC in this matter,
* as is Netscape.
*
*/
var bitSet = new BitSet(128);
bitSet.set('a', 'z' + 1);
bitSet.set('A', 'Z' + 1);
bitSet.set('0', '9' + 1);
bitSet.set(' '); /* encoding a space to a + is done
* in the encode() method */
bitSet.set('-');
bitSet.set('_');
bitSet.set('.');
bitSet.set('*');
DONT_NEED_ENCODING = ImmutableBitSetPredicate.of(bitSet);
}
/**
* You can't call the constructor.
*/
private URLEncoder() { }
/**
* Translates a string into {@code x-www-form-urlencoded}
* format. This method uses the default charset
* as the encoding scheme to obtain the bytes for unsafe characters.
*
* @param s {@code String} to be translated.
* @deprecated The resulting string may vary depending on the
* default charset. Instead, use the encode(String,String)
* method to specify the encoding.
* @return the translated {@code String}.
*/
@Deprecated
public static String encode(String s) {
return encode(s, Charset.defaultCharset());
}
/**
* Translates a string into {@code application/x-www-form-urlencoded}
* format using a specific encoding scheme.
* <p>
* This method behaves the same as {@linkplain #encode(String s, Charset charset)}
* except that it will {@linkplain Charset#forName look up the charset}
* using the given encoding name.
*
* @param s {@code String} to be translated.
* @param enc The name of a supported
* <a href="../lang/package-summary.html#charenc">character
* encoding</a>.
* @return the translated {@code String}.
* @throws UnsupportedEncodingException
* If the named encoding is not supported
* @see URLDecoder#decode(java.lang.String, java.lang.String)
* @since 1.4
*/
public static String encode(String s, String enc)
throws UnsupportedEncodingException {
if (enc == null) {
throw new NullPointerException("charsetName");
}
try {
Charset charset = Charset.forName(enc);
return encode(s, charset);
} catch (IllegalCharsetNameException | UnsupportedCharsetException e) {
throw new UnsupportedEncodingException(enc);
}
}
private static final int ENCODING_CHUNK_SIZE = 8;
/**
* Translates a string into {@code application/x-www-form-urlencoded}
* format using a specific {@linkplain Charset Charset}.
* This method uses the supplied charset to obtain the bytes for unsafe
* characters.
* <p>
* If the input string is malformed, or if the input cannot be mapped
* to a valid byte sequence in the given {@code Charset}, then the
* erroneous input will be replaced with the {@code Charset}'s
* {@linkplain CharsetEncoder##cae replacement values}.
*
* @apiNote The <a href=
* "http://www.w3.org/TR/html40/appendix/notes.html#non-ascii-chars">
* World Wide Web Consortium Recommendation</a> states that
* UTF-8 should be used. Not doing so may introduce incompatibilities.
* @param s {@code String} to be translated.
* @param charset the given charset
* @return the translated {@code String}.
* @throws NullPointerException if {@code s} or {@code charset} is {@code null}.
* @spec https://www.w3.org/TR/html4 HTML 4.01 Specification
* @see URLDecoder#decode(java.lang.String, Charset)
* @since 10
*/
public static String encode(String s, Charset charset) {
Objects.requireNonNull(charset, "charset");
int i;
for (i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (!DONT_NEED_ENCODING.test(c) || c == ' ') {
break;
}
}
if (i == s.length()) {
return s;
}
StringBuilder out = new StringBuilder(s.length() << 1);
if (i > 0) {
out.append(s, 0, i);
}
CharsetEncoder ce = charset.newEncoder()
.onMalformedInput(CodingErrorAction.REPLACE)
.onUnmappableCharacter(CodingErrorAction.REPLACE);
CharBuffer cb = CharBuffer.allocate(ENCODING_CHUNK_SIZE);
ByteBuffer bb = ByteBuffer.allocate((int)(ENCODING_CHUNK_SIZE * ce.maxBytesPerChar()));
while (i < s.length()) {
char c = s.charAt(i);
if (DONT_NEED_ENCODING.test(c)) {
if (c == ' ') {
c = '+';
}
out.append(c);
i++;
} else {
// convert to external encoding before hex conversion
do {
cb.put(c);
/*
* If this character represents the start of a Unicode
* surrogate pair, then pass in two characters. It's not
* clear what should be done if a byte reserved in the
* surrogate pairs range occurs outside a legal
* surrogate pair. For now, just treat it as if it were
* any other character.
*/
if (Character.isHighSurrogate(c)) {
if ((i + 1) < s.length()) {
char d = s.charAt(i + 1);
if (Character.isLowSurrogate(d)) {
cb.put(d);
i++;
}
}
}
// Limit to ENCODING_CHUNK_SIZE - 1 so that we can always fit in
// a surrogate pair on the next iteration
if (cb.position() >= ENCODING_CHUNK_SIZE - 1) {
flushToStringBuilder(out, ce, cb, bb, false);
}
i++;
} while (i < s.length() && !DONT_NEED_ENCODING.test((c = s.charAt(i))));
flushToStringBuilder(out, ce, cb, bb, true);
}
}
return out.toString();
}
/**
* Encodes input chars in {@code cb} and appends the byte values in an escaped
* format ({@code "%XX"}) to {@code out}. The temporary byte buffer, {@code bb},
* must be able to accept {@code cb.position() * ce.maxBytesPerChar()} bytes.
*
* @param out the StringBuilder to output encoded and escaped bytes to
* @param ce charset encoder. Will be reset if endOfInput is true
* @param cb input buffer, will be cleared
* @param bb output buffer, will be cleared
* @param endOfInput true if this is the last flush for an encoding chunk,
* to all bytes in ce is flushed to out and reset
*/
private static void flushToStringBuilder(StringBuilder out,
CharsetEncoder ce,
CharBuffer cb,
ByteBuffer bb,
boolean endOfInput) {
cb.flip();
try {
CoderResult cr = ce.encode(cb, bb, endOfInput);
if (!cr.isUnderflow())
cr.throwException();
if (endOfInput) {
cr = ce.flush(bb);
if (!cr.isUnderflow())
cr.throwException();
ce.reset();
}
} catch (CharacterCodingException x) {
throw new Error(x); // Can't happen
}
HexFormat hex = HexFormat.of().withUpperCase();
byte[] bytes = bb.array();
int len = bb.position();
for (int i = 0; i < len; i++) {
out.append('%');
hex.toHexDigits(out, bytes[i]);
}
cb.clear();
bb.clear();
}
}