/*
* 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 com.alimama.mdrill.utils.zip;
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;
/**
* A ZipEncoding, which uses a java.nio {@link
* java.nio.charset.Charset Charset} to encode names.
*
* <p>This implementation works for all cases under java-1.5 or
* later. However, in java-1.4, some charsets don't have a java.nio
* implementation, most notably the default ZIP encoding Cp437.</p>
*
* <p>The methods of this class are reentrant.</p>
*/
class NioZipEncoding implements ZipEncoding {
private final Charset charset;
/**
* Construct an NIO based zip encoding, which wraps the given
* charset.
*
* @param charset The NIO charset to wrap.
*/
public NioZipEncoding(Charset charset) {
this.charset = charset;
}
/**
* @see
* com.alimama.mdrill.utils.zip.ZipEncoding#canEncode(java.lang.String)
*/
public boolean canEncode(String name) {
CharsetEncoder enc = this.charset.newEncoder();
enc.onMalformedInput(CodingErrorAction.REPORT);
enc.onUnmappableCharacter(CodingErrorAction.REPORT);
return enc.canEncode(name);
}
/**
* @see
* com.alimama.mdrill.utils.zip.ZipEncoding#encode(java.lang.String)
*/
public ByteBuffer encode(String name) {
CharsetEncoder enc = this.charset.newEncoder();
enc.onMalformedInput(CodingErrorAction.REPORT);
enc.onUnmappableCharacter(CodingErrorAction.REPORT);
CharBuffer cb = CharBuffer.wrap(name);
ByteBuffer out = ByteBuffer.allocate(name.length()
+ (name.length() + 1) / 2);
while (cb.remaining() > 0) {
CoderResult res = enc.encode(cb, out,true);
if (res.isUnmappable() || res.isMalformed()) {
// write the unmappable characters in utf-16
// pseudo-URL encoding style to ByteBuffer.
if (res.length() * 6 > out.remaining()) {
out = ZipEncodingHelper.growBuffer(out, out.position()
+ res.length() * 6);
}
for (int i=0; i<res.length(); ++i) {
ZipEncodingHelper.appendSurrogate(out,cb.get());
}
} else if (res.isOverflow()) {
out = ZipEncodingHelper.growBuffer(out, 0);
} else if (res.isUnderflow()) {
enc.flush(out);
break;
}
}
out.limit(out.position());
out.rewind();
return out;
}
/**
* @see
* com.alimama.mdrill.utils.zip.ZipEncoding#decode(byte[])
*/
public String decode(byte[] data) throws IOException {
return this.charset.newDecoder()
.onMalformedInput(CodingErrorAction.REPORT)
.onUnmappableCharacter(CodingErrorAction.REPORT)
.decode(ByteBuffer.wrap(data)).toString();
}
}