StrictUtf8.java
/*
* Copyright (c) 2012, 2017 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.tyrus.core;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;
/* Legal UTF-8 Byte Sequences
*
* # Code Points Bits Bit/Byte pattern
* 1 7 0xxxxxxx
* U+0000..U+007F 00..7F
*
* 2 11 110xxxxx 10xxxxxx
* U+0080..U+07FF C2..DF 80..BF
*
* 3 16 1110xxxx 10xxxxxx 10xxxxxx
* U+0800..U+0FFF E0 A0..BF 80..BF
* U+1000..U+FFFF E1..EF 80..BF 80..BF
*
* 4 21 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
* U+10000..U+3FFFF F0 90..BF 80..BF 80..BF
* U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF
* U+100000..U10FFFF F4 80..8F 80..BF 80..BF
*
*/
public class StrictUtf8 extends Charset {
public StrictUtf8() {
super("StrictUtf8", new String[]{});
}
@Override
public CharsetDecoder newDecoder() {
return new Decoder(this);
}
@Override
public CharsetEncoder newEncoder() {
return new Encoder(this);
}
@Override
public boolean contains(Charset cs) {
return "StrictUtf8".equals(cs.name());
}
private static boolean isSurrogate(char ch) {
return ch >= Character.MIN_SURROGATE && ch < (Character.MAX_SURROGATE + 1);
}
private static char highSurrogate(int codePoint) {
return (char) ((codePoint >>> 10) + (Character.MIN_HIGH_SURROGATE
- (Character.MIN_SUPPLEMENTARY_CODE_POINT >>> 10)));
}
private static char lowSurrogate(int codePoint) {
return (char) ((codePoint & 0x3ff) + Character.MIN_LOW_SURROGATE);
}
private static void updatePositions(ByteBuffer src, int sp, CharBuffer dst, int dp) {
src.position(sp - src.arrayOffset());
dst.position(dp - dst.arrayOffset());
}
private static void updatePositions(CharBuffer src, int sp, ByteBuffer dst, int dp) {
src.position(sp - src.arrayOffset());
dst.position(dp - dst.arrayOffset());
}
private static class Decoder extends CharsetDecoder {
private Decoder(Charset cs) {
super(cs, 1.0f, 1.0f);
}
private static boolean isNotContinuation(int b) {
return (b & 0xc0) != 0x80;
}
// decode() now checks the first byte of 2-byte sequence as
// if ((b1 >> 5) == -2 && (b1 & 0x1e) != 0)
// ...
// no longer need to check b1 against c1 & c0 for malformed
//
// [C2..DF] [80..BF]
//private static boolean isMalformed2(int b1, int b2) {
// return (b1 & 0x1e) == 0x0 || (b2 & 0xc0) != 0x80;
//}
// [E0] [A0..BF] [80..BF]
// [E1..EF] [80..BF] [80..BF]
private static boolean isMalformed3(int b1, int b2, int b3) {
return (b1 == (byte) 0xe0 && (b2 & 0xe0) == 0x80) || (b2 & 0xc0) != 0x80 || (b3 & 0xc0) != 0x80;
}
// only used when there is only one byte left in src buffer
private static boolean isMalformed3_2(int b1, int b2) {
return (b1 == (byte) 0xe0 && (b2 & 0xe0) == 0x80) || (b2 & 0xc0) != 0x80;
}
// [F0] [90..BF] [80..BF] [80..BF]
// [F1..F3] [80..BF] [80..BF] [80..BF]
// [F4] [80..8F] [80..BF] [80..BF]
// only check 80-be range here, the [0xf0,0x80...] and [0xf4,0x90-...]
// will be checked by Character.isSupplementaryCodePoint(uc)
private static boolean isMalformed4(int b2, int b3, int b4) {
return (b2 & 0xc0) != 0x80 || (b3 & 0xc0) != 0x80 || (b4 & 0xc0) != 0x80;
}
// only used when there is less than 4 bytes left in src buffer
private static boolean isMalformed4_2(int b1, int b2) {
return (b1 == 0xf0 && b2 == 0x90) || (b2 & 0xc0) != 0x80;
}
private static boolean isMalformed4_3(int b3) {
return (b3 & 0xc0) != 0x80;
}
private static CoderResult malformedN(ByteBuffer src, int nb) {
switch (nb) {
case 1:
case 2: // always 1
return CoderResult.malformedForLength(1);
case 3:
int b1 = src.get();
int b2 = src.get(); // no need to lookup b3
return CoderResult.malformedForLength(((b1 == (byte) 0xe0 && (b2 & 0xe0) == 0x80)
|| isNotContinuation(b2)) ? 1 : 2);
case 4: // we don't care the speed here
b1 = src.get() & 0xff;
b2 = src.get() & 0xff;
if (b1 > 0xf4 || (b1 == 0xf0 && (b2 < 0x90 || b2 > 0xbf)) || (b1 == 0xf4 && (b2 & 0xf0) != 0x80)
|| isNotContinuation(b2)) {
return CoderResult.malformedForLength(1);
}
if (isNotContinuation(src.get())) {
return CoderResult.malformedForLength(2);
}
return CoderResult.malformedForLength(3);
default:
assert false;
return null;
}
}
private static CoderResult malformed(ByteBuffer src, int sp, CharBuffer dst, int dp, int nb) {
src.position(sp - src.arrayOffset());
CoderResult cr = malformedN(src, nb);
updatePositions(src, sp, dst, dp);
return cr;
}
private static CoderResult malformed(ByteBuffer src, int mark, int nb) {
src.position(mark);
CoderResult cr = malformedN(src, nb);
src.position(mark);
return cr;
}
private static CoderResult malformedForLength(ByteBuffer src, int sp, CharBuffer dst, int dp, int malformedNB) {
updatePositions(src, sp, dst, dp);
return CoderResult.malformedForLength(malformedNB);
}
private static CoderResult malformedForLength(ByteBuffer src, int mark, int malformedNB) {
src.position(mark);
return CoderResult.malformedForLength(malformedNB);
}
private static CoderResult xflow(ByteBuffer src, int sp, int sl, CharBuffer dst, int dp, int nb) {
updatePositions(src, sp, dst, dp);
return (nb == 0 || sl - sp < nb) ? CoderResult.UNDERFLOW : CoderResult.OVERFLOW;
}
private static CoderResult xflow(Buffer src, int mark, int nb) {
src.position(mark);
return (nb == 0 || src.remaining() < nb) ? CoderResult.UNDERFLOW : CoderResult.OVERFLOW;
}
private CoderResult decodeArrayLoop(ByteBuffer src, CharBuffer dst) {
// This method is optimized for ASCII input.
byte[] sa = src.array();
int sp = src.arrayOffset() + src.position();
int sl = src.arrayOffset() + src.limit();
char[] da = dst.array();
int dp = dst.arrayOffset() + dst.position();
int dl = dst.arrayOffset() + dst.limit();
int dlASCII = dp + Math.min(sl - sp, dl - dp);
// ASCII only loop
while (dp < dlASCII && sa[sp] >= 0) {
da[dp++] = (char) sa[sp++];
}
while (sp < sl) {
int b1 = sa[sp];
if (b1 >= 0) {
// 1 byte, 7 bits: 0xxxxxxx
if (dp >= dl) {
return xflow(src, sp, sl, dst, dp, 1);
}
da[dp++] = (char) b1;
sp++;
} else if ((b1 >> 5) == -2 && (b1 & 0x1e) != 0) {
// 2 bytes, 11 bits: 110xxxxx 10xxxxxx
if (sl - sp < 2 || dp >= dl) {
return xflow(src, sp, sl, dst, dp, 2);
}
int b2 = sa[sp + 1];
if (isNotContinuation(b2)) {
return malformedForLength(src, sp, dst, dp, 1);
}
da[dp++] = (char) (((b1 << 6) ^ b2) ^ (((byte) 0xC0 << 6) ^ ((byte) 0x80)));
sp += 2;
} else if ((b1 >> 4) == -2) {
// 3 bytes, 16 bits: 1110xxxx 10xxxxxx 10xxxxxx
int srcRemaining = sl - sp;
if (srcRemaining < 3 || dp >= dl) {
if (srcRemaining > 1 && isMalformed3_2(b1, sa[sp + 1])) {
return malformedForLength(src, sp, dst, dp, 1);
}
return xflow(src, sp, sl, dst, dp, 3);
}
int b2 = sa[sp + 1];
int b3 = sa[sp + 2];
if (isMalformed3(b1, b2, b3)) {
return malformed(src, sp, dst, dp, 3);
}
char c = (char) ((b1 << 12) ^ (b2 << 6) ^ (b3 ^ (((byte) 0xE0 << 12) ^ ((byte) 0x80 << 6)
^ ((byte) 0x80))));
if (isSurrogate(c)) {
return malformedForLength(src, sp, dst, dp, 3);
}
da[dp++] = c;
sp += 3;
} else if ((b1 >> 3) == -2) {
// 4 bytes, 21 bits: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
int srcRemaining = sl - sp;
if (srcRemaining < 4 || dl - dp < 2) {
if (srcRemaining > 1 && isMalformed4_2(b1, sa[sp + 1])) {
return malformedForLength(src, sp, dst, dp, 1);
}
if (srcRemaining > 2 && isMalformed4_3(sa[sp + 2])) {
return malformedForLength(src, sp, dst, dp, 2);
}
return xflow(src, sp, sl, dst, dp, 4);
}
int b2 = sa[sp + 1];
int b3 = sa[sp + 2];
int b4 = sa[sp + 3];
int uc = ((b1 << 18) ^ (b2 << 12) ^ (b3 << 6) ^ (b4
^ (((byte) 0xF0 << 18) ^ ((byte) 0x80 << 12) ^ ((byte) 0x80 << 6) ^ ((byte) 0x80))));
if (isMalformed4(b2, b3, b4)
// shortest form check
|| !Character.isSupplementaryCodePoint(uc)) {
return malformed(src, sp, dst, dp, 4);
}
da[dp++] = highSurrogate(uc);
da[dp++] = lowSurrogate(uc);
sp += 4;
} else {
return malformed(src, sp, dst, dp, 1);
}
}
return xflow(src, sp, sl, dst, dp, 0);
}
private CoderResult decodeBufferLoop(ByteBuffer src, CharBuffer dst) {
int mark = src.position();
int limit = src.limit();
while (mark < limit) {
int b1 = src.get();
if (b1 >= 0) {
// 1 byte, 7 bits: 0xxxxxxx
if (dst.remaining() < 1) {
return xflow(src, mark, 1); // overflow
}
dst.put((char) b1);
mark++;
} else if ((b1 >> 5) == -2 && (b1 & 0x1e) != 0) {
// 2 bytes, 11 bits: 110xxxxx 10xxxxxx
if (limit - mark < 2 || dst.remaining() < 1) {
return xflow(src, mark, 2);
}
int b2 = src.get();
if (isNotContinuation(b2)) {
return malformedForLength(src, mark, 1);
}
dst.put((char) (((b1 << 6) ^ b2) ^ (((byte) 0xC0 << 6) ^ ((byte) 0x80))));
mark += 2;
} else if ((b1 >> 4) == -2) {
// 3 bytes, 16 bits: 1110xxxx 10xxxxxx 10xxxxxx
int srcRemaining = limit - mark;
if (srcRemaining < 3 || dst.remaining() < 1) {
if (srcRemaining > 1 && isMalformed3_2(b1, src.get())) {
return malformedForLength(src, mark, 1);
}
return xflow(src, mark, 3);
}
int b2 = src.get();
int b3 = src.get();
if (isMalformed3(b1, b2, b3)) {
return malformed(src, mark, 3);
}
char c = (char) ((b1 << 12) ^ (b2 << 6) ^ (b3 ^ (((byte) 0xE0 << 12) ^ ((byte) 0x80 << 6)
^ ((byte) 0x80))));
if (isSurrogate(c)) {
return malformedForLength(src, mark, 3);
}
dst.put(c);
mark += 3;
} else if ((b1 >> 3) == -2) {
// 4 bytes, 21 bits: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
int srcRemaining = limit - mark;
if (srcRemaining < 4 || dst.remaining() < 2) {
if (srcRemaining > 1 && isMalformed4_2(b1, src.get())) {
return malformedForLength(src, mark, 1);
}
if (srcRemaining > 2 && isMalformed4_3(src.get())) {
return malformedForLength(src, mark, 2);
}
return xflow(src, mark, 4);
}
int b2 = src.get();
int b3 = src.get();
int b4 = src.get();
int uc = ((b1 << 18) ^ (b2 << 12) ^ (b3 << 6) ^ (b4 ^ (((byte) 0xF0 << 18) ^ ((byte) 0x80 << 12)
^ ((byte) 0x80 << 6) ^ ((byte) 0x80))));
if (isMalformed4(b2, b3, b4)
// shortest form check
|| !Character.isSupplementaryCodePoint(uc)) {
return malformed(src, mark, 4);
}
dst.put(highSurrogate(uc));
dst.put(lowSurrogate(uc));
mark += 4;
} else {
return malformed(src, mark, 1);
}
}
return xflow(src, mark, 0);
}
@Override
protected CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {
if (src.hasArray() && dst.hasArray()) {
return decodeArrayLoop(src, dst);
} else {
return decodeBufferLoop(src, dst);
}
}
private static ByteBuffer getByteBuffer(ByteBuffer bb, byte[] ba, int sp) {
if (bb == null) {
bb = ByteBuffer.wrap(ba);
}
bb.position(sp);
return bb;
}
// returns -1 if there is/are malformed byte(s) and the
// "action" for malformed input is not REPLACE.
public int decode(byte[] sa, int sp, int len, char[] da) {
final int sl = sp + len;
int dp = 0;
int dlASCII = Math.min(len, da.length);
ByteBuffer bb = null; // only necessary if malformed
// ASCII only optimized loop
while (dp < dlASCII && sa[sp] >= 0) {
da[dp++] = (char) sa[sp++];
}
while (sp < sl) {
int b1 = sa[sp++];
if (b1 >= 0) {
// 1 byte, 7 bits: 0xxxxxxx
da[dp++] = (char) b1;
} else if ((b1 >> 5) == -2 && (b1 & 0x1e) != 0) {
// 2 bytes, 11 bits: 110xxxxx 10xxxxxx
if (sp < sl) {
int b2 = sa[sp++];
if (isNotContinuation(b2)) {
if (malformedInputAction() != CodingErrorAction.REPLACE) {
return -1;
}
da[dp++] = replacement().charAt(0);
sp--; // malformedN(bb, 2) always returns 1
} else {
da[dp++] = (char) (((b1 << 6) ^ b2) ^ (((byte) 0xC0 << 6) ^ ((byte) 0x80)));
}
continue;
}
if (malformedInputAction() != CodingErrorAction.REPLACE) {
return -1;
}
da[dp++] = replacement().charAt(0);
return dp;
} else if ((b1 >> 4) == -2) {
// 3 bytes, 16 bits: 1110xxxx 10xxxxxx 10xxxxxx
if (sp + 1 < sl) {
int b2 = sa[sp++];
int b3 = sa[sp++];
if (isMalformed3(b1, b2, b3)) {
if (malformedInputAction() != CodingErrorAction.REPLACE) {
return -1;
}
da[dp++] = replacement().charAt(0);
sp -= 3;
bb = getByteBuffer(bb, sa, sp);
sp += malformedN(bb, 3).length();
} else {
char c = (char) ((b1 << 12) ^ (b2 << 6) ^ (b3 ^ (((byte) 0xE0 << 12) ^ ((byte) 0x80 << 6)
^ ((byte) 0x80))));
if (isSurrogate(c)) {
if (malformedInputAction() != CodingErrorAction.REPLACE) {
return -1;
}
da[dp++] = replacement().charAt(0);
} else {
da[dp++] = c;
}
}
continue;
}
if (malformedInputAction() != CodingErrorAction.REPLACE) {
return -1;
}
if (sp < sl && isMalformed3_2(b1, sa[sp])) {
da[dp++] = replacement().charAt(0);
continue;
}
da[dp++] = replacement().charAt(0);
return dp;
} else if ((b1 >> 3) == -2) {
// 4 bytes, 21 bits: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
if (sp + 2 < sl) {
int b2 = sa[sp++];
int b3 = sa[sp++];
int b4 = sa[sp++];
int uc = ((b1 << 18) ^ (b2 << 12) ^ (b3 << 6) ^ (b4 ^ (((byte) 0xF0 << 18) ^ ((byte) 0x80 << 12)
^ ((byte) 0x80 << 6) ^ ((byte) 0x80))));
if (isMalformed4(b2, b3, b4)
// shortest form check
|| !Character.isSupplementaryCodePoint(uc)) {
if (malformedInputAction() != CodingErrorAction.REPLACE) {
return -1;
}
da[dp++] = replacement().charAt(0);
sp -= 4;
bb = getByteBuffer(bb, sa, sp);
sp += malformedN(bb, 4).length();
} else {
da[dp++] = highSurrogate(uc);
da[dp++] = lowSurrogate(uc);
}
continue;
}
if (malformedInputAction() != CodingErrorAction.REPLACE) {
return -1;
}
if (sp < sl && isMalformed4_2(b1, sa[sp])) {
da[dp++] = replacement().charAt(0);
continue;
}
sp++;
if (sp < sl && isMalformed4_3(sa[sp])) {
da[dp++] = replacement().charAt(0);
continue;
}
da[dp++] = replacement().charAt(0);
return dp;
} else {
if (malformedInputAction() != CodingErrorAction.REPLACE) {
return -1;
}
da[dp++] = replacement().charAt(0);
}
}
return dp;
}
}
static final class Encoder extends CharsetEncoder {
private Encoder(Charset cs) {
super(cs, 1.1f, 3.0f);
}
@Override
public boolean canEncode(char c) {
return !isSurrogate(c);
}
@Override
public boolean isLegalReplacement(byte[] repl) {
return ((repl.length == 1 && repl[0] >= 0) || super.isLegalReplacement(repl));
}
private static CoderResult overflow(CharBuffer src, int sp, ByteBuffer dst, int dp) {
updatePositions(src, sp, dst, dp);
return CoderResult.OVERFLOW;
}
private static CoderResult overflow(CharBuffer src, int mark) {
src.position(mark);
return CoderResult.OVERFLOW;
}
private Parser sgp;
private CoderResult encodeArrayLoop(CharBuffer src, ByteBuffer dst) {
char[] sa = src.array();
int sp = src.arrayOffset() + src.position();
int sl = src.arrayOffset() + src.limit();
byte[] da = dst.array();
int dp = dst.arrayOffset() + dst.position();
int dl = dst.arrayOffset() + dst.limit();
int dlASCII = dp + Math.min(sl - sp, dl - dp);
// ASCII only loop
while (dp < dlASCII && sa[sp] < '\u0080') {
da[dp++] = (byte) sa[sp++];
}
while (sp < sl) {
char c = sa[sp];
if (c < 0x80) {
// Have at most seven bits
if (dp >= dl) {
return overflow(src, sp, dst, dp);
}
da[dp++] = (byte) c;
} else if (c < 0x800) {
// 2 bytes, 11 bits
if (dl - dp < 2) {
return overflow(src, sp, dst, dp);
}
da[dp++] = (byte) (0xc0 | (c >> 6));
da[dp++] = (byte) (0x80 | (c & 0x3f));
} else if (isSurrogate(c)) {
// Have a surrogate pair
if (sgp == null) {
sgp = new Parser();
}
int uc = sgp.parse(c, sa, sp, sl);
if (uc < 0) {
updatePositions(src, sp, dst, dp);
return sgp.error();
}
if (dl - dp < 4) {
return overflow(src, sp, dst, dp);
}
da[dp++] = (byte) (0xf0 | ((uc >> 18)));
da[dp++] = (byte) (0x80 | ((uc >> 12) & 0x3f));
da[dp++] = (byte) (0x80 | ((uc >> 6) & 0x3f));
da[dp++] = (byte) (0x80 | (uc & 0x3f));
sp++; // 2 chars
} else {
// 3 bytes, 16 bits
if (dl - dp < 3) {
return overflow(src, sp, dst, dp);
}
da[dp++] = (byte) (0xe0 | ((c >> 12)));
da[dp++] = (byte) (0x80 | ((c >> 6) & 0x3f));
da[dp++] = (byte) (0x80 | (c & 0x3f));
}
sp++;
}
updatePositions(src, sp, dst, dp);
return CoderResult.UNDERFLOW;
}
private CoderResult encodeBufferLoop(CharBuffer src, ByteBuffer dst) {
int mark = src.position();
while (src.hasRemaining()) {
char c = src.get();
if (c < 0x80) {
// Have at most seven bits
if (!dst.hasRemaining()) {
return overflow(src, mark);
}
dst.put((byte) c);
} else if (c < 0x800) {
// 2 bytes, 11 bits
if (dst.remaining() < 2) {
return overflow(src, mark);
}
dst.put((byte) (0xc0 | (c >> 6)));
dst.put((byte) (0x80 | (c & 0x3f)));
} else if (isSurrogate(c)) {
// Have a surrogate pair
if (sgp == null) {
sgp = new Parser();
}
int uc = sgp.parse(c, src);
if (uc < 0) {
src.position(mark);
return sgp.error();
}
if (dst.remaining() < 4) {
return overflow(src, mark);
}
dst.put((byte) (0xf0 | ((uc >> 18))));
dst.put((byte) (0x80 | ((uc >> 12) & 0x3f)));
dst.put((byte) (0x80 | ((uc >> 6) & 0x3f)));
dst.put((byte) (0x80 | (uc & 0x3f)));
mark++; // 2 chars
} else {
// 3 bytes, 16 bits
if (dst.remaining() < 3) {
return overflow(src, mark);
}
dst.put((byte) (0xe0 | ((c >> 12))));
dst.put((byte) (0x80 | ((c >> 6) & 0x3f)));
dst.put((byte) (0x80 | (c & 0x3f)));
}
mark++;
}
src.position(mark);
return CoderResult.UNDERFLOW;
}
@Override
protected final CoderResult encodeLoop(CharBuffer src, ByteBuffer dst) {
if (src.hasArray() && dst.hasArray()) {
return encodeArrayLoop(src, dst);
} else {
return encodeBufferLoop(src, dst);
}
}
// returns -1 if there is malformed char(s) and the
// "action" for malformed input is not REPLACE.
public int encode(char[] sa, int sp, int len, byte[] da) {
int sl = sp + len;
int dp = 0;
int dlASCII = dp + Math.min(len, da.length);
// ASCII only optimized loop
while (dp < dlASCII && sa[sp] < '\u0080') {
da[dp++] = (byte) sa[sp++];
}
while (sp < sl) {
char c = sa[sp++];
if (c < 0x80) {
// Have at most seven bits
da[dp++] = (byte) c;
} else if (c < 0x800) {
// 2 bytes, 11 bits
da[dp++] = (byte) (0xc0 | (c >> 6));
da[dp++] = (byte) (0x80 | (c & 0x3f));
} else if (isSurrogate(c)) {
if (sgp == null) {
sgp = new Parser();
}
int uc = sgp.parse(c, sa, sp - 1, sl);
if (uc < 0) {
if (malformedInputAction() != CodingErrorAction.REPLACE) {
return -1;
}
da[dp++] = replacement()[0];
} else {
da[dp++] = (byte) (0xf0 | ((uc >> 18)));
da[dp++] = (byte) (0x80 | ((uc >> 12) & 0x3f));
da[dp++] = (byte) (0x80 | ((uc >> 6) & 0x3f));
da[dp++] = (byte) (0x80 | (uc & 0x3f));
sp++; // 2 chars
}
} else {
// 3 bytes, 16 bits
da[dp++] = (byte) (0xe0 | ((c >> 12)));
da[dp++] = (byte) (0x80 | ((c >> 6) & 0x3f));
da[dp++] = (byte) (0x80 | (c & 0x3f));
}
}
return dp;
}
}
/**
* Surrogate parsing support. Charset implementations may use instances of this class to handle the details of
* parsing UTF-16 surrogate pairs.
*/
public static class Parser {
private CoderResult error = CoderResult.UNDERFLOW;
/**
* If the previous parse operation detected an error, return the object describing that error.
*
* @return object describing encountered parse error.
*/
public CoderResult error() {
assert (error != null);
return error;
}
/**
* Parses a UCS-4 character from the given source buffer, handling surrogates.
*
* @param c The first character
* @param in The source buffer, from which one more character will be consumed if c is a high surrogate
* @return Either a parsed UCS-4 character, in which case the isPair() and increment() methods will return
* meaningful values, or -1, in which case error() will return a descriptive result object
*/
public int parse(char c, CharBuffer in) {
int character; // UCS-4
if (Character.isHighSurrogate(c)) {
if (!in.hasRemaining()) {
error = CoderResult.UNDERFLOW;
return -1;
}
char d = in.get();
if (Character.isLowSurrogate(d)) {
character = Character.toCodePoint(c, d);
error = null;
return character;
}
error = CoderResult.malformedForLength(1);
return -1;
}
if (Character.isLowSurrogate(c)) {
error = CoderResult.malformedForLength(1);
return -1;
}
character = c;
error = null;
return character;
}
/**
* Parses a UCS-4 character from the given source buffer, handling surrogates.
*
* @param c The first character
* @param ia The input array, from which one more character will be consumed if c is a high surrogate
* @param ip The input index
* @param il The input limit
* @return Either a parsed UCS-4 character, in which case the isPair() and increment() methods will return
* meaningful values, or -1, in which case error() will return a descriptive result object
*/
public int parse(char c, char[] ia, int ip, int il) {
int character; // UCS-4
assert (ia[ip] == c);
if (Character.isHighSurrogate(c)) {
if (il - ip < 2) {
error = CoderResult.UNDERFLOW;
return -1;
}
char d = ia[ip + 1];
if (Character.isLowSurrogate(d)) {
character = Character.toCodePoint(c, d);
error = null;
return character;
}
error = CoderResult.malformedForLength(1);
return -1;
}
if (Character.isLowSurrogate(c)) {
error = CoderResult.malformedForLength(1);
return -1;
}
character = c;
error = null;
return character;
}
}
}