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 */ 019package org.apache.commons.compress.compressors.xz; 020 021import java.io.IOException; 022import java.io.OutputStream; 023 024import org.apache.commons.compress.compressors.CompressorOutputStream; 025import org.tukaani.xz.LZMA2Options; 026import org.tukaani.xz.XZOutputStream; 027 028/** 029 * XZ compressor. 030 * 031 * @since 1.4 032 */ 033public class XZCompressorOutputStream extends CompressorOutputStream { 034 private final XZOutputStream out; 035 036 /** 037 * Creates a new XZ compressor using the default LZMA2 options. This is equivalent to {@code XZCompressorOutputStream(outputStream, 6)}. 038 * 039 * @param outputStream the stream to wrap 040 * @throws IOException on error 041 */ 042 public XZCompressorOutputStream(final OutputStream outputStream) throws IOException { 043 out = new XZOutputStream(outputStream, new LZMA2Options()); 044 } 045 046 /** 047 * Creates a new XZ compressor using the specified LZMA2 preset level. 048 * <p> 049 * The presets 0-3 are fast presets with medium compression. The presets 4-6 are fairly slow presets with high compression. The default preset is 6. 050 * <p> 051 * The presets 7-9 are like the preset 6 but use bigger dictionaries and have higher compressor and decompressor memory requirements. Unless the 052 * uncompressed size of the file exceeds 8 MiB, 16 MiB, or 32 MiB, it is waste of memory to use the presets 7, 8, or 9, respectively. 053 * 054 * @param outputStream the stream to wrap 055 * @param preset the preset 056 * @throws IOException on error 057 */ 058 public XZCompressorOutputStream(final OutputStream outputStream, final int preset) throws IOException { 059 out = new XZOutputStream(outputStream, new LZMA2Options(preset)); 060 } 061 062 @Override 063 public void close() throws IOException { 064 out.close(); 065 } 066 067 /** 068 * Finishes compression without closing the underlying stream. No more data can be written to this stream after finishing. 069 * 070 * @throws IOException on error 071 */ 072 public void finish() throws IOException { 073 out.finish(); 074 } 075 076 /** 077 * Flushes the encoder and calls {@code outputStream.flush()}. All buffered pending data will then be decompressible from the output stream. Calling this 078 * function very often may increase the compressed file size a lot. 079 */ 080 @Override 081 public void flush() throws IOException { 082 out.flush(); 083 } 084 085 @Override 086 public void write(final byte[] buf, final int off, final int len) throws IOException { 087 out.write(buf, off, len); 088 } 089 090 @Override 091 public void write(final int b) throws IOException { 092 out.write(b); 093 } 094}