Java tutorial
/* * Copyright (c) 1996, 1999, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.util.zip; import java.io.FilterOutputStream; import java.io.OutputStream; import java.io.IOException; /** * An output stream that also maintains a checksum of the data being * written. The checksum can then be used to verify the integrity of * the output data. * * @see Checksum * @author David Connelly * @since 1.1 */ public class CheckedOutputStream extends FilterOutputStream { private Checksum cksum; /** * Creates an output stream with the specified Checksum. * @param out the output stream * @param cksum the checksum */ public CheckedOutputStream(OutputStream out, Checksum cksum) { super(out); this.cksum = cksum; } /** * Writes a byte. Will block until the byte is actually written. * @param b the byte to be written * @exception IOException if an I/O error has occurred */ public void write(int b) throws IOException { out.write(b); cksum.update(b); } /** * Writes an array of bytes. Will block until the bytes are * actually written. * @param b the data to be written * @param off the start offset of the data * @param len the number of bytes to be written * @exception IOException if an I/O error has occurred */ public void write(byte[] b, int off, int len) throws IOException { out.write(b, off, len); cksum.update(b, off, len); } /** * Returns the Checksum for this output stream. * @return the Checksum */ public Checksum getChecksum() { return cksum; } }