151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski/* 251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved. 351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * This code is free software; you can redistribute it and/or modify it 651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * under the terms of the GNU General Public License version 2 only, as 751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * published by the Free Software Foundation. Oracle designates this 851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * particular file as subject to the "Classpath" exception as provided 951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * by Oracle in the LICENSE file that accompanied this code. 1051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 1151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * This code is distributed in the hope that it will be useful, but WITHOUT 1251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * version 2 for more details (a copy is included in the LICENSE file that 1551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * accompanied this code). 1651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 1751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * You should have received a copy of the GNU General Public License version 1851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 2 along with this work; if not, write to the Free Software Foundation, 1951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 2151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * or visit www.oracle.com if you need additional information or have any 2351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * questions. 2451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 2551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 2651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskipackage java.util.zip; 2751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 2851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskiimport java.io.FilterInputStream; 2951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskiimport java.io.InputStream; 3051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskiimport java.io.IOException; 3151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 3251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski/** 3351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * An input stream that also maintains a checksum of the data being read. 3451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * The checksum can then be used to verify the integrity of the input data. 3551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * 3651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @see Checksum 3751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @author David Connelly 3851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 3951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskipublic 4051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebskiclass CheckedInputStream extends FilterInputStream { 4151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski private Checksum cksum; 4251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 4351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 4451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Creates an input stream using the specified Checksum. 4551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param in the input stream 4651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param cksum the Checksum 4751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 4851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public CheckedInputStream(InputStream in, Checksum cksum) { 4951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski super(in); 5051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski this.cksum = cksum; 5151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 5251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 5351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 5451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Reads a byte. Will block if no input is available. 5551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return the byte read, or -1 if the end of the stream is reached. 5651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @exception IOException if an I/O error has occurred 5751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 5851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public int read() throws IOException { 5951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski int b = in.read(); 6051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (b != -1) { 6151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski cksum.update(b); 6251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 6351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return b; 6451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 6551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 6651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 6751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Reads into an array of bytes. If <code>len</code> is not zero, the method 6851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * blocks until some input is available; otherwise, no 6951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * bytes are read and <code>0</code> is returned. 7051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param buf the buffer into which the data is read 7151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param off the start offset in the destination array <code>b</code> 7251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param len the maximum number of bytes read 7351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return the actual number of bytes read, or -1 if the end 7451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * of the stream is reached. 7551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @exception NullPointerException If <code>buf</code> is <code>null</code>. 7651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @exception IndexOutOfBoundsException If <code>off</code> is negative, 7751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <code>len</code> is negative, or <code>len</code> is greater than 7851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * <code>buf.length - off</code> 7951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @exception IOException if an I/O error has occurred 8051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 8151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public int read(byte[] buf, int off, int len) throws IOException { 8251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski len = in.read(buf, off, len); 8351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (len != -1) { 8451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski cksum.update(buf, off, len); 8551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 8651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return len; 8751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 8851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 8951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 9051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Skips specified number of bytes of input. 9151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @param n the number of bytes to skip 9251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return the actual number of bytes skipped 9351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @exception IOException if an I/O error has occurred 9451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 9551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public long skip(long n) throws IOException { 9651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski byte[] buf = new byte[512]; 9751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski long total = 0; 9851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski while (total < n) { 9951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski long len = n - total; 10051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski len = read(buf, 0, len < buf.length ? (int)len : buf.length); 10151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski if (len == -1) { 10251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return total; 10351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 10451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski total += len; 10551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 10651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return total; 10751b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 10851b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski 10951b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski /** 11051b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * Returns the Checksum for this input stream. 11151b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski * @return the Checksum value 11251b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski */ 11351b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski public Checksum getChecksum() { 11451b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski return cksum; 11551b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski } 11651b1b6997fd3f980076b8081f7f1165ccc2a4008Piotr Jastrzebski} 117