/*

  * 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.io.input;

 import java.io.IOException;

 import java.io.InputStream;

 /**

  * Data written to this stream is forwarded to a stream that has been associated

  * with this thread.

  *

  * @version $Id: DemuxInputStream.java 1415850 2012-11-30 20:51:39Z ggregory $

  */

 public class DemuxInputStream

     extends InputStream

 {

     private final InheritableThreadLocal<InputStream> m_streams = new InheritableThreadLocal<InputStream>();

     /**

      * Bind the specified stream to the current thread.

      *

      * @param input the stream to bind

      * @return the InputStream that was previously active

      */

     public InputStream bindStream( final InputStream input )

     {

         final InputStream oldValue = m_streams.get();

         m_streams.set( input );

         return oldValue;

     }

     /**

      * Closes stream associated with current thread.

      *

      * @throws IOException if an error occurs

      */

     @Override

     public void close()

         throws IOException

     {

         final InputStream input = m_streams.get();

         if( null != input )

         {

             input.close();

         }

     }

     /**

      * Read byte from stream associated with current thread.

      *

      * @return the byte read from stream

      * @throws IOException if an error occurs

      */

     @Override

     public int read()

         throws IOException

     {

         final InputStream input = m_streams.get();

         if( null != input )

         {

             return input.read();

         }

         else

         {

             return -1;

         }

     }

 }