/*
* 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.commons.compress.compressors;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;
import org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream;
import org.apache.commons.compress.compressors.pack200.Pack200CompressorInputStream;
import org.apache.commons.compress.compressors.pack200.Pack200CompressorOutputStream;
/**
* <p>Factory to create Compressor[In|Out]putStreams from names. To add other
* implementations you should extend CompressorStreamFactory and override the
* appropriate methods (and call their implementation from super of course).</p>
*
* Example (Compressing a file):
*
* <pre>
* final OutputStream out = new FileOutputStream(output);
* CompressorOutputStream cos =
* new CompressorStreamFactory().createCompressorOutputStream(CompressorStreamFactory.BZIP2, out);
* IOUtils.copy(new FileInputStream(input), cos);
* cos.close();
* </pre>
*
* Example (Compressing a file):
* <pre>
* final InputStream is = new FileInputStream(input);
* CompressorInputStream in =
* new CompressorStreamFactory().createCompressorInputStream(CompressorStreamFactory.BZIP2, is);
* IOUtils.copy(in, new FileOutputStream(output));
* in.close();
* </pre>
*
* @Immutable
*/
public class CompressorStreamFactory {
/**
* Constant used to identify the BZIP2 compression algorithm.
* @since Commons Compress 1.1
*/
public static final String BZIP2 = "bzip2";
/**
* Constant used to identify the GZIP compression algorithm.
* @since Commons Compress 1.1
*/
public static final String GZIP = "gz";
/**
* Constant used to identify the PACK200 compression algorithm.
* @since Commons Compress 1.3
*/
public static final String PACK200 = "pack200";
/**
* Create an compressor input stream from an input stream, autodetecting
* the compressor type from the first few bytes of the stream. The InputStream
* must support marks, like BufferedInputStream.
*
* @param in the input stream
* @return the compressor input stream
* @throws CompressorException if the compressor name is not known
* @throws IllegalArgumentException if the stream is null or does not support mark
* @since Commons Compress 1.1
*/
public CompressorInputStream createCompressorInputStream(final InputStream in)
throws CompressorException {
if (in == null) {
throw new IllegalArgumentException("Stream must not be null.");
}
if (!in.markSupported()) {
throw new IllegalArgumentException("Mark is not supported.");
}
final byte[] signature = new byte[12];
in.mark(signature.length);
try {
int signatureLength = in.read(signature);
in.reset();
if (BZip2CompressorInputStream.matches(signature, signatureLength)) {
return new BZip2CompressorInputStream(in);
}
if (GzipCompressorInputStream.matches(signature, signatureLength)) {
return new GzipCompressorInputStream(in);
}
if (Pack200CompressorInputStream.matches(signature, signatureLength)) {
return new Pack200CompressorInputStream(in);
}
} catch (IOException e) {
throw new CompressorException("Failed to detect Compressor from InputStream.", e);
}
throw new CompressorException("No Compressor found for the stream signature.");
}
/**
* Create a compressor input stream from a compressor name and an input stream.
*
* @param name of the compressor, i.e. "gz", "bzip2" or "pack200"
* @param in the input stream
* @return compressor input stream
* @throws CompressorException if the compressor name is not known
* @throws IllegalArgumentException if the name or input stream is null
*/
public CompressorInputStream createCompressorInputStream(final String name,
final InputStream in) throws CompressorException {
if (name == null || in == null) {
throw new IllegalArgumentException(
"Compressor name and stream must not be null.");
}
try {
if (GZIP.equalsIgnoreCase(name)) {
return new GzipCompressorInputStream(in);
}
if (BZIP2.equalsIgnoreCase(name)) {
return new BZip2CompressorInputStream(in);
}
if (PACK200.equalsIgnoreCase(name)) {
return new Pack200CompressorInputStream(in);
}
} catch (IOException e) {
throw new CompressorException(
"Could not create CompressorInputStream.", e);
}
throw new CompressorException("Compressor: " + name + " not found.");
}
/**
* Create an compressor output stream from an compressor name and an input stream.
*
* @param name the compressor name, i.e. "gz", "bzip2" or "pack200"
* @param out the output stream
* @return the compressor output stream
* @throws CompressorException if the archiver name is not known
* @throws IllegalArgumentException if the archiver name or stream is null
*/
public CompressorOutputStream createCompressorOutputStream(
final String name, final OutputStream out)
throws CompressorException {
if (name == null || out == null) {
throw new IllegalArgumentException(
"Compressor name and stream must not be null.");
}
try {
if (GZIP.equalsIgnoreCase(name)) {
return new GzipCompressorOutputStream(out);
}
if (BZIP2.equalsIgnoreCase(name)) {
return new BZip2CompressorOutputStream(out);
}
if (PACK200.equalsIgnoreCase(name)) {
return new Pack200CompressorOutputStream(out);
}
} catch (IOException e) {
throw new CompressorException(
"Could not create CompressorOutputStream", e);
}
throw new CompressorException("Compressor: " + name + " not found.");
}
}