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view src/org/eclipse/jetty/util/Utf8Appendable.java @ 984:7b0fa315e835
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author | Franklin Schmidt <fschmidt@gmail.com> |
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date | Sun, 16 Oct 2016 23:11:15 -0600 |
parents | 8e9db0bbf4f9 |
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// // ======================================================================== // Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd. // ------------------------------------------------------------------------ // All rights reserved. This program and the accompanying materials // are made available under the terms of the Eclipse Public License v1.0 // and Apache License v2.0 which accompanies this distribution. // // The Eclipse Public License is available at // http://www.eclipse.org/legal/epl-v10.html // // The Apache License v2.0 is available at // http://www.opensource.org/licenses/apache2.0.php // // You may elect to redistribute this code under either of these licenses. // ======================================================================== // package org.eclipse.jetty.util; import java.io.IOException; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /* ------------------------------------------------------------ */ /** * Utf8 Appendable abstract base class * * This abstract class wraps a standard {@link java.lang.Appendable} and provides methods to append UTF-8 encoded bytes, that are converted into characters. * * This class is stateful and up to 4 calls to {@link #append(byte)} may be needed before state a character is appended to the string buffer. * * The UTF-8 decoding is done by this class and no additional buffers or Readers are used. The UTF-8 code was inspired by * http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ * * License information for Bjoern Hoehrmann's code: * * Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de> * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. **/ public abstract class Utf8Appendable { protected static final Logger LOG = LoggerFactory.getLogger(Utf8Appendable.class); public static final char REPLACEMENT = '\ufffd'; private static final int UTF8_ACCEPT = 0; private static final int UTF8_REJECT = 12; protected final Appendable _appendable; protected int _state = UTF8_ACCEPT; private static final byte[] BYTE_TABLE = { // The first part of the table maps bytes to character classes that // to reduce the size of the transition table and create bitmasks. 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 10,3,3,3,3,3,3,3,3,3,3,3,3,4,3,3, 11,6,6,6,5,8,8,8,8,8,8,8,8,8,8,8 }; private static final byte[] TRANS_TABLE = { // The second part is a transition table that maps a combination // of a state of the automaton and a character class to a state. 0,12,24,36,60,96,84,12,12,12,48,72, 12,12,12,12,12,12,12,12,12,12,12,12, 12, 0,12,12,12,12,12, 0,12, 0,12,12, 12,24,12,12,12,12,12,24,12,24,12,12, 12,12,12,12,12,12,12,24,12,12,12,12, 12,24,12,12,12,12,12,12,12,24,12,12, 12,12,12,12,12,12,12,36,12,36,12,12, 12,36,12,12,12,12,12,36,12,36,12,12, 12,36,12,12,12,12,12,12,12,12,12,12 }; private int _codep; public Utf8Appendable(Appendable appendable) { _appendable = appendable; } public abstract int length(); protected void reset() { _state = UTF8_ACCEPT; } public void append(byte b) { try { appendByte(b); } catch (IOException e) { throw new RuntimeException(e); } } public void append(byte[] b, int offset, int length) { try { int end = offset + length; for (int i = offset; i < end; i++) appendByte(b[i]); } catch (IOException e) { throw new RuntimeException(e); } } public boolean append(byte[] b, int offset, int length, int maxChars) { try { int end = offset + length; for (int i = offset; i < end; i++) { if (length() > maxChars) return false; appendByte(b[i]); } return true; } catch (IOException e) { throw new RuntimeException(e); } } protected void appendByte(byte b) throws IOException { if (b > 0 && _state == UTF8_ACCEPT) { _appendable.append((char)(b & 0xFF)); } else { int i = b & 0xFF; int type = BYTE_TABLE[i]; _codep = _state == UTF8_ACCEPT ? (0xFF >> type) & i : (i & 0x3F) | (_codep << 6); int next = TRANS_TABLE[_state + type]; switch(next) { case UTF8_ACCEPT: _state=next; if (_codep < Character.MIN_HIGH_SURROGATE) { _appendable.append((char)_codep); } else { for (char c : Character.toChars(_codep)) _appendable.append(c); } break; case UTF8_REJECT: String reason = "byte "+TypeUtil.toHexString(b)+" in state "+(_state/12); _codep=0; _state = UTF8_ACCEPT; _appendable.append(REPLACEMENT); throw new NotUtf8Exception(reason); default: _state=next; } } } public boolean isUtf8SequenceComplete() { return _state == UTF8_ACCEPT; } public static class NotUtf8Exception extends IllegalArgumentException { public NotUtf8Exception(String reason) { super("Not valid UTF8! "+reason); } } protected void checkState() { if (!isUtf8SequenceComplete()) { _codep=0; _state = UTF8_ACCEPT; try { _appendable.append(REPLACEMENT); } catch(IOException e) { throw new RuntimeException(e); } throw new NotUtf8Exception("incomplete UTF8 sequence"); } } public String toReplacedString() { if (!isUtf8SequenceComplete()) { _codep=0; _state = UTF8_ACCEPT; try { _appendable.append(REPLACEMENT); } catch(IOException e) { throw new RuntimeException(e); } Throwable th= new NotUtf8Exception("incomplete UTF8 sequence"); LOG.warn(th.toString()); LOG.debug("",th); } return _appendable.toString(); } }