001    // Copyright 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.util.io;
016    
017    import java.io.IOException;
018    import java.io.OutputStream;
019    
020    import org.apache.hivemind.util.Defense;
021    
022    /**
023     * An output stream that copies bytes pushed through it to two other output streams.
024     * 
025     * @author Howard M. Lewis Ship
026     * @since 4.0
027     */
028    public class TeeOutputStream extends OutputStream
029    {
030        private final OutputStream _os1;
031    
032        private final OutputStream _os2;
033    
034        public TeeOutputStream(OutputStream os1, OutputStream os2)
035        {
036            Defense.notNull(os1, "os1");
037            Defense.notNull(os2, "os2");
038    
039            _os1 = os1;
040            _os2 = os2;
041        }
042    
043        public void close() throws IOException
044        {
045            _os1.close();
046            _os2.close();
047        }
048    
049        public void flush() throws IOException
050        {
051            _os1.flush();
052            _os2.flush();
053        }
054    
055        public void write(byte[] b, int off, int len) throws IOException
056        {
057            _os1.write(b, off, len);
058            _os2.write(b, off, len);
059        }
060    
061        public void write(byte[] b) throws IOException
062        {
063            _os1.write(b);
064            _os1.write(b);
065        }
066    
067        public void write(int b) throws IOException
068        {
069            _os1.write(b);
070            _os2.write(b);
071        }
072    }