CountingOutputStream.java

/*
 * Copyright (C) 2014 Jörg Prante
 *
 * Licensed 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.xbib.io;

import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * Stream that tracks the number of bytes read.
 */
public class CountingOutputStream extends FilterOutputStream {
    private long bytesWritten = 0;

    public CountingOutputStream(final OutputStream out) {
        super(out);
    }

    @Override
    public void write(int b) throws IOException {
        out.write(b);
        count(1);
    }

    @Override
    public void write(byte[] b) throws IOException {
        write(b, 0, b.length);
    }

    @Override
    public void write(byte[] b, int off, 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(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;
    }
}