1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package java.util.zip; 19 20 import java.io.FilterOutputStream; 21 import java.io.IOException; 22 import java.io.OutputStream; 23 import java.util.Arrays; 24 25 /** 26 * An {@code OutputStream} filter to decompress data. Callers write 27 * compressed data in the "deflate" format, and uncompressed data is 28 * written to the underlying stream. 29 * @since 1.6 30 */ 31 public class InflaterOutputStream extends FilterOutputStream { 32 private static final int DEFAULT_BUFFER_SIZE = 1024; 33 34 protected final Inflater inf; 35 protected final byte[] buf; 36 37 private boolean closed = false; 38 39 /** 40 * Constructs an {@code InflaterOutputStream} with a new {@code Inflater} and an 41 * implementation-defined default internal buffer size. {@code out} is a destination 42 * for uncompressed data, and compressed data will be written to this stream. 43 * 44 * @param out the destination {@code OutputStream} 45 */ 46 public InflaterOutputStream(OutputStream out) { 47 this(out, new Inflater()); 48 } 49 50 /** 51 * Constructs an {@code InflaterOutputStream} with the given {@code Inflater} and an 52 * implementation-defined default internal buffer size. {@code out} is a destination 53 * for uncompressed data, and compressed data will be written to this stream. 54 * 55 * @param out the destination {@code OutputStream} 56 * @param inf the {@code Inflater} to be used for decompression 57 */ 58 public InflaterOutputStream(OutputStream out, Inflater inf) { 59 this(out, inf, DEFAULT_BUFFER_SIZE); 60 } 61 62 /** 63 * Constructs an {@code InflaterOutputStream} with the given {@code Inflater} and 64 * given internal buffer size. {@code out} is a destination 65 * for uncompressed data, and compressed data will be written to this stream. 66 * 67 * @param out the destination {@code OutputStream} 68 * @param inf the {@code Inflater} to be used for decompression 69 * @param bufferSize the length in bytes of the internal buffer 70 */ 71 public InflaterOutputStream(OutputStream out, Inflater inf, int bufferSize) { 72 super(out); 73 if (out == null) { 74 throw new NullPointerException("out == null"); 75 } else if (inf == null) { 76 throw new NullPointerException("inf == null"); 77 } 78 if (bufferSize <= 0) { 79 throw new IllegalArgumentException("bufferSize <= 0: " + bufferSize); 80 } 81 this.inf = inf; 82 this.buf = new byte[bufferSize]; 83 } 84 85 /** 86 * Writes remaining data into the output stream and closes the underlying 87 * output stream. 88 */ 89 @Override 90 public void close() throws IOException { 91 if (!closed) { 92 finish(); 93 inf.end(); 94 out.close(); 95 closed = true; 96 } 97 } 98 99 @Override 100 public void flush() throws IOException { 101 finish(); 102 out.flush(); 103 } 104 105 /** 106 * Finishes writing current uncompressed data into the InflaterOutputStream 107 * without closing it. 108 * 109 * @throws IOException if an I/O error occurs, or the stream has been closed 110 */ 111 public void finish() throws IOException { 112 checkClosed(); 113 write(); 114 } 115 116 /** 117 * Writes a byte to the decompressing output stream. {@code b} should be a byte of 118 * compressed input. The corresponding uncompressed data will be written to the underlying 119 * stream. 120 * 121 * @param b the byte 122 * @throws IOException if an I/O error occurs, or the stream has been closed 123 * @throws ZipException if a zip exception occurs. 124 */ 125 @Override 126 public void write(int b) throws IOException, ZipException { 127 write(new byte[] { (byte) b }, 0, 1); 128 } 129 130 /** 131 * Writes to the decompressing output stream. The {@code bytes} array should contain 132 * compressed input. The corresponding uncompressed data will be written to the underlying 133 * stream. 134 * 135 * @throws IOException if an I/O error occurs, or the stream has been closed 136 * @throws ZipException if a zip exception occurs. 137 * @throws NullPointerException if {@code b == null}. 138 * @throws IndexOutOfBoundsException if {@code off < 0 || len < 0 || off + len > b.length} 139 */ 140 @Override 141 public void write(byte[] bytes, int offset, int byteCount) throws IOException, ZipException { 142 checkClosed(); 143 Arrays.checkOffsetAndCount(bytes.length, offset, byteCount); 144 inf.setInput(bytes, offset, byteCount); 145 write(); 146 } 147 148 private void write() throws IOException, ZipException { 149 try { 150 int inflated; 151 while ((inflated = inf.inflate(buf)) > 0) { 152 out.write(buf, 0, inflated); 153 } 154 } catch (DataFormatException e) { 155 throw new ZipException(); 156 } 157 } 158 159 private void checkClosed() throws IOException { 160 if (closed) { 161 throw new IOException(); 162 } 163 } 164 } 165
