Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package org.apache.commons.compress.utils; import java.io.FilterOutputStream; import java.io.IOException; import java.io.OutputStream; /** * Stream that tracks the number of bytes read. * @since 1.3 * @NotThreadSafe */ public class CountingOutputStream extends FilterOutputStream { private long bytesWritten = 0; public CountingOutputStream(final OutputStream out) { super(out); } @Override public void write(final int b) throws IOException { out.write(b); count(1); } @Override public void write(final byte[] b) throws IOException { write(b, 0, b.length); } @Override public void write(final byte[] b, final int off, final int len) throws IOException { out.write(b, off, len); count(len); } /** * Increments the counter of already written bytes. * Doesn't increment if the EOF has been hit (written == -1) * * @param written the number of bytes written */ protected void count(final long written) { if (written != -1) { bytesWritten += written; } } /** * Returns the current number of bytes written to this stream. * @return the number of written bytes */ public long getBytesWritten() { return bytesWritten; } }