1/* 2 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package com.sun.imageio.plugins.common; 27 28import java.io.IOException; 29import javax.imageio.stream.ImageInputStreamImpl; 30import javax.imageio.stream.ImageInputStream; 31 32public final class SubImageInputStream extends ImageInputStreamImpl { 33 34 ImageInputStream stream; 35 long startingPos; 36 int startingLength; 37 int length; 38 39 public SubImageInputStream(ImageInputStream stream, int length) 40 throws IOException { 41 this.stream = stream; 42 this.startingPos = stream.getStreamPosition(); 43 this.startingLength = this.length = length; 44 } 45 46 public int read() throws IOException { 47 if (length == 0) { // Local EOF 48 return -1; 49 } else { 50 --length; 51 return stream.read(); 52 } 53 } 54 55 public int read(byte[] b, int off, int len) throws IOException { 56 if (length == 0) { // Local EOF 57 return -1; 58 } 59 60 len = Math.min(len, length); 61 int bytes = stream.read(b, off, len); 62 length -= bytes; 63 return bytes; 64 } 65 66 public long length() { 67 return startingLength; 68 } 69 70 public void seek(long pos) throws IOException { 71 stream.seek(pos - startingPos); 72 streamPos = pos; 73 } 74 75 @SuppressWarnings("deprecation") 76 protected void finalize() throws Throwable { 77 // Empty finalizer (for improved performance; no need to call 78 // super.finalize() in this case) 79 } 80} 81