001    /*
002     * Copyright (C) 2007 The Guava Authors
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package com.google.common.io;
018    
019    import com.google.common.annotations.Beta;
020    
021    import java.io.FilterOutputStream;
022    import java.io.IOException;
023    import java.io.OutputStream;
024    
025    /**
026     * An OutputStream that counts the number of bytes written.
027     *
028     * @author Chris Nokleberg
029     * @since 1
030     */
031    @Beta
032    public final class CountingOutputStream extends FilterOutputStream {
033    
034      private long count;
035    
036      /**
037       * Wraps another output stream, counting the number of bytes written.
038       *
039       * @param out the output stream to be wrapped
040       */
041      public CountingOutputStream(OutputStream out) {
042        super(out);
043      }
044    
045      /** Returns the number of bytes written. */
046      public long getCount() {
047        return count;
048      }
049    
050      @Override public void write(byte[] b, int off, int len) throws IOException {
051        out.write(b, off, len);
052        count += len;
053      }
054    
055      @Override public void write(int b) throws IOException {
056        out.write(b);
057        count++;
058      }
059    }