001 /* CheckedOutputStream.java - Compute checksum of data being written. 002 Copyright (C) 1999, 2000 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package java.util.zip; 040 041 import java.io.FilterOutputStream; 042 import java.io.IOException; 043 import java.io.OutputStream; 044 045 /* Written using on-line Java Platform 1.2 API Specification 046 * and JCL book. 047 * Believed complete and correct. 048 */ 049 050 /** 051 * OutputStream that computes a checksum of data being written using a 052 * supplied Checksum object. 053 * 054 * @see Checksum 055 * 056 * @author Tom Tromey 057 * @date May 17, 1999 058 */ 059 public class CheckedOutputStream extends FilterOutputStream 060 { 061 /** 062 * Creates a new CheckInputStream on top of the supplied OutputStream 063 * using the supplied Checksum. 064 */ 065 public CheckedOutputStream (OutputStream out, Checksum cksum) 066 { 067 super (out); 068 this.sum = cksum; 069 } 070 071 /** 072 * Returns the Checksum object used. To get the data checksum computed so 073 * far call <code>getChecksum.getValue()</code>. 074 */ 075 public Checksum getChecksum () 076 { 077 return sum; 078 } 079 080 /** 081 * Writes one byte to the OutputStream and updates the Checksum. 082 */ 083 public void write (int bval) throws IOException 084 { 085 out.write(bval); 086 sum.update(bval); 087 } 088 089 /** 090 * Writes the byte array to the OutputStream and updates the Checksum. 091 */ 092 public void write (byte[] buf, int off, int len) throws IOException 093 { 094 out.write(buf, off, len); 095 sum.update(buf, off, len); 096 } 097 098 /** The checksum object. */ 099 private Checksum sum; 100 }