1 /* 2 * Copyright 2013, Google Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * * Neither the name of Google Inc. nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 package org.jf.util; 33 34 import javax.annotation.Nonnull; 35 import java.io.IOException; 36 import java.io.InputStream; 37 import java.io.RandomAccessFile; 38 39 public class RandomAccessFileInputStream extends InputStream { 40 private int filePosition; 41 @Nonnull private final RandomAccessFile raf; 42 RandomAccessFileInputStream(@onnull RandomAccessFile raf, int filePosition)43 public RandomAccessFileInputStream(@Nonnull RandomAccessFile raf, int filePosition) { 44 this.filePosition = filePosition; 45 this.raf = raf; 46 } 47 read()48 @Override public int read() throws IOException { 49 raf.seek(filePosition); 50 filePosition++; 51 return raf.read(); 52 } 53 read(byte[] bytes)54 @Override public int read(byte[] bytes) throws IOException { 55 raf.seek(filePosition); 56 int bytesRead = raf.read(bytes); 57 filePosition += bytesRead; 58 return bytesRead; 59 } 60 read(byte[] bytes, int offset, int length)61 @Override public int read(byte[] bytes, int offset, int length) throws IOException { 62 raf.seek(filePosition); 63 int bytesRead = raf.read(bytes, offset, length); 64 filePosition += bytesRead; 65 return bytesRead; 66 } 67 skip(long l)68 @Override public long skip(long l) throws IOException { 69 int skipBytes = Math.min((int)l, available()); 70 filePosition += skipBytes; 71 return skipBytes; 72 } 73 available()74 @Override public int available() throws IOException { 75 return (int)raf.length() - filePosition; 76 } 77 markSupported()78 @Override public boolean markSupported() { 79 return false; 80 } 81 } 82