001/* CheckedOutputStream.java - Compute checksum of data being written. 002 Copyright (C) 1999, 2000 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.util.zip; 040 041import java.io.FilterOutputStream; 042import java.io.IOException; 043import 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 */ 059public 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}