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/*
* 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.
*/
/**
*
* Provides stream classes for compressing and decompressing streams using the Pack200 algorithm used to compress Java archives.
*
*
* The streams of this package only work on JAR archives, i.e. a {@link org.apache.commons.compress.compressors.pack200.Pack200CompressorOutputStream
* Pack200CompressorOutputStream} expects to be wrapped around a stream that a valid JAR archive will be written to and a
* {@link org.apache.commons.compress.compressors.pack200.Pack200CompressorInputStream Pack200CompressorInputStream} provides a stream to read from a JAR
* archive.
*
*
* JAR archives compressed with Pack200 will in general be different from the original archive when decompressed again. For details see the
* API documentation of Pack200.
*
*
* The streams of this package work on non-deflated streams, i.e. archives like those created with the --no-gzip option of the JDK's
* pack200 command line tool. If you want to work on deflated streams you must use an additional stream layer - for example by using Apache Commons
* Compress' gzip package.
*
*
* The Pack200 API provided by the Java class library doesn't lend itself to real stream processing. Pack200CompressorInputStream will uncompress
* its input immediately and then provide an InputStream to a cached result. Likewise Pack200CompressorOutputStream will not write
* anything to the given OutputStream until finish or close is called - at which point the cached output written so far gets
* compressed.
*
*
* Two different caching modes are available - "in memory", which is the default, and "temporary file". By default data is cached in memory but you should
* switch to the temporary file option if your archives are really big.
*
*
* Given there always is an intermediate result the getBytesRead and getCount methods of Pack200CompressorInputStream are
* meaningless (read from the real stream or from the intermediate result?) and always return 0.
*
*
* During development of the initial version several attempts have been made to use a real streaming API based for example on
* Piped(In|Out)putStream or explicit stream pumping like Commons Exec's InputStreamPumper but they have all failed because they rely
* on the output end to be consumed completely or else the (un)pack will block forever. Especially for Pack200InputStream it is very
* likely that it will be wrapped in a ZipArchiveInputStream which will never read the archive completely as it is not interested in the ZIP
* central directory data at the end of the JAR archive.
*
*/
package org.apache.commons.compress.compressors.pack200;