1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * https://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 */ 19 package org.apache.commons.compress.utils; 20 21 import java.io.IOException; 22 import java.nio.ByteBuffer; 23 import java.nio.channels.SeekableByteChannel; 24 25 /** 26 * InputStream that delegates requests to the underlying SeekableByteChannel, making sure that only bytes from a certain range can be read. 27 * 28 * @ThreadSafe 29 * @since 1.21 30 */ 31 public class BoundedSeekableByteChannelInputStream extends BoundedArchiveInputStream { 32 33 private final SeekableByteChannel channel; 34 35 /** 36 * Constructs a bounded stream on the underlying {@link SeekableByteChannel} 37 * 38 * @param start Position in the stream from where the reading of this bounded stream starts 39 * @param remaining Amount of bytes which are allowed to read from the bounded stream 40 * @param channel Channel which the reads will be delegated to 41 */ 42 public BoundedSeekableByteChannelInputStream(final long start, final long remaining, final SeekableByteChannel channel) { 43 super(start, remaining); 44 this.channel = channel; 45 } 46 47 @Override 48 protected int read(final long pos, final ByteBuffer buf) throws IOException { 49 final int read; 50 synchronized (channel) { 51 channel.position(pos); 52 read = channel.read(buf); 53 } 54 buf.flip(); 55 return read; 56 } 57 }