001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019 package org.apache.commons.compress.compressors; 020 021 import java.io.IOException; 022 import java.io.InputStream; 023 import java.io.OutputStream; 024 025 import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream; 026 import org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream; 027 import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream; 028 import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream; 029 030 /** 031 * <p>Factory to create Compressor[In|Out]putStreams from names. To add other 032 * implementations you should extend CompressorStreamFactory and override the 033 * appropriate methods (and call their implementation from super of course).</p> 034 * 035 * Example (Compressing a file): 036 * 037 * <pre> 038 * final OutputStream out = new FileOutputStream(output); 039 * CompressorOutputStream cos = 040 * new CompressorStreamFactory().createCompressorOutputStream("bzip2", out); 041 * IOUtils.copy(new FileInputStream(input), cos); 042 * cos.close(); 043 * </pre> 044 * 045 * Example (Compressing a file): 046 * <pre> 047 * final InputStream is = new FileInputStream(input); 048 * CompressorInputStream in = 049 * new CompressorStreamFactory().createCompressorInputStream("bzip2", is); 050 * IOUtils.copy(in, new FileOutputStream(output)); 051 * in.close(); 052 * </pre> 053 * 054 * @Immutable 055 */ 056 public class CompressorStreamFactory { 057 058 /** 059 * Create a compressor input stream from a compressor name and an input stream. 060 * 061 * @param name of the compressor, i.e. "gz" or "bzip2" 062 * @param in the input stream 063 * @return compressor input stream 064 * @throws CompressorException if the compressor name is not known 065 * @throws IllegalArgumentException if the name or input stream is null 066 */ 067 public CompressorInputStream createCompressorInputStream(final String name, 068 final InputStream in) throws CompressorException { 069 if (name == null || in == null) { 070 throw new IllegalArgumentException( 071 "Compressor name and stream must not be null."); 072 } 073 074 try { 075 if ("gz".equalsIgnoreCase(name)) { 076 return new GzipCompressorInputStream(in); 077 } else if ("bzip2".equalsIgnoreCase(name)) { 078 return new BZip2CompressorInputStream(in); 079 } 080 } catch (IOException e) { 081 throw new CompressorException( 082 "Could not create CompressorInputStream", e); 083 } 084 throw new CompressorException("Compressor: " + name + " not found."); 085 } 086 087 /** 088 * Create an compressor output stream from an compressor name and an input stream. 089 * 090 * @param name the compressor name, i.e. "gz" or "bzip2" 091 * @param out the output stream 092 * @return the compressor output stream 093 * @throws CompressorException if the archiver name is not known 094 * @throws IllegalArgumentException if the archiver name or stream is null 095 */ 096 public CompressorOutputStream createCompressorOutputStream( 097 final String name, final OutputStream out) 098 throws CompressorException { 099 if (name == null || out == null) { 100 throw new IllegalArgumentException( 101 "Compressor name and stream must not be null."); 102 } 103 104 try { 105 if ("gz".equalsIgnoreCase(name)) { 106 return new GzipCompressorOutputStream(out); 107 } else if ("bzip2".equalsIgnoreCase(name)) { 108 return new BZip2CompressorOutputStream(out); 109 } 110 } catch (IOException e) { 111 throw new CompressorException( 112 "Could not create CompressorOutputStream", e); 113 } 114 throw new CompressorException("Compressor: " + name + " not found."); 115 } 116 }