org.apache.tomcat.util.buf.C2BConverter Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.tomcat.util.buf;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.ExceptionUtils;
import org.apache.tomcat.util.res.StringManager;
/**
* NIO based character encoder.
*/
public final class C2BConverter {
private static final Log log = LogFactory.getLog(C2BConverter.class);
private static final StringManager sm = StringManager.getManager(C2BConverter.class);
private final CharsetEncoder encoder;
private ByteBuffer bb = null;
private CharBuffer cb = null;
/**
* Leftover buffer used for multi-characters characters.
*/
private final CharBuffer leftovers;
public C2BConverter(Charset charset) {
encoder = charset.newEncoder();
encoder.onUnmappableCharacter(CodingErrorAction.REPLACE)
.onMalformedInput(CodingErrorAction.REPLACE);
char[] left = new char[4];
leftovers = CharBuffer.wrap(left);
}
/**
* Reset the encoder state.
*/
public void recycle() {
try {
encoder.reset();
} catch (Throwable t) {
ExceptionUtils.handleThrowable(t);
log.warn(sm.getString("c2bConverter.decoderResetFail", encoder.charset()), t);
}
leftovers.position(0);
}
public boolean isUndeflow() {
return (leftovers.position() > 0);
}
/**
* Convert the given characters to bytes.
*
* @param cc char input
* @param bc byte output
* @throws IOException An encoding error occurred
*/
public void convert(CharChunk cc, ByteChunk bc) throws IOException {
if ((bb == null) || (bb.array() != bc.getBuffer())) {
// Create a new byte buffer if anything changed
bb = ByteBuffer.wrap(bc.getBuffer(), bc.getEnd(), bc.getBuffer().length - bc.getEnd());
} else {
// Initialize the byte buffer
bb.limit(bc.getBuffer().length);
bb.position(bc.getEnd());
}
if ((cb == null) || (cb.array() != cc.getBuffer())) {
// Create a new char buffer if anything changed
cb = CharBuffer.wrap(cc.getBuffer(), cc.getStart(), cc.getLength());
} else {
// Initialize the char buffer
cb.limit(cc.getEnd());
cb.position(cc.getStart());
}
CoderResult result = null;
// Parse leftover if any are present
if (leftovers.position() > 0) {
int pos = bb.position();
// Loop until one char is encoded or there is a encoder error
do {
leftovers.put((char) cc.subtract());
leftovers.flip();
result = encoder.encode(leftovers, bb, false);
leftovers.position(leftovers.limit());
leftovers.limit(leftovers.array().length);
} while (result.isUnderflow() && (bb.position() == pos));
if (result.isError() || result.isMalformed()) {
result.throwException();
}
cb.position(cc.getStart());
leftovers.position(0);
}
// Do the decoding and get the results into the byte chunk and the char
// chunk
result = encoder.encode(cb, bb, false);
if (result.isError() || result.isMalformed()) {
result.throwException();
} else if (result.isOverflow()) {
// Propagate current positions to the byte chunk and char chunk
bc.setEnd(bb.position());
cc.setOffset(cb.position());
} else if (result.isUnderflow()) {
// Propagate current positions to the byte chunk and char chunk
bc.setEnd(bb.position());
cc.setOffset(cb.position());
// Put leftovers in the leftovers char buffer
if (cc.getLength() > 0) {
leftovers.limit(leftovers.array().length);
leftovers.position(cc.getLength());
cc.subtract(leftovers.array(), 0, cc.getLength());
}
}
}
/**
* Convert the given characters to bytes.
*
* @param cc char input
* @param bc byte output
* @throws IOException An encoding error occurred
*/
public void convert(CharBuffer cc, ByteBuffer bc) throws IOException {
if ((bb == null) || (bb.array() != bc.array())) {
// Create a new byte buffer if anything changed
bb = ByteBuffer.wrap(bc.array(), bc.limit(), bc.capacity() - bc.limit());
} else {
// Initialize the byte buffer
bb.limit(bc.capacity());
bb.position(bc.limit());
}
if ((cb == null) || (cb.array() != cc.array())) {
// Create a new char buffer if anything changed
cb = CharBuffer.wrap(cc.array(), cc.arrayOffset() + cc.position(), cc.remaining());
} else {
// Initialize the char buffer
cb.limit(cc.limit());
cb.position(cc.position());
}
CoderResult result = null;
// Parse leftover if any are present
if (leftovers.position() > 0) {
int pos = bb.position();
// Loop until one char is encoded or there is a encoder error
do {
leftovers.put(cc.get());
leftovers.flip();
result = encoder.encode(leftovers, bb, false);
leftovers.position(leftovers.limit());
leftovers.limit(leftovers.array().length);
} while (result.isUnderflow() && (bb.position() == pos));
if (result.isError() || result.isMalformed()) {
result.throwException();
}
cb.position(cc.position());
leftovers.position(0);
}
// Do the decoding and get the results into the byte chunk and the char
// chunk
result = encoder.encode(cb, bb, false);
if (result.isError() || result.isMalformed()) {
result.throwException();
} else if (result.isOverflow()) {
// Propagate current positions to the byte chunk and char chunk
bc.limit(bb.position());
cc.position(cb.position());
} else if (result.isUnderflow()) {
// Propagate current positions to the byte chunk and char chunk
bc.limit(bb.position());
cc.position(cb.position());
// Put leftovers in the leftovers char buffer
if (cc.remaining() > 0) {
leftovers.limit(leftovers.array().length);
leftovers.position(cc.remaining());
cc.get(leftovers.array(), 0, cc.remaining());
}
}
}
public Charset getCharset() {
return encoder.charset();
}
}