001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  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 distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.rest;
014
015import java.io.*;
016
017import javax.servlet.*;
018
019import org.apache.juneau.encoders.*;
020
021/**
022 * A wrapped {@link ServletOutputStream} with an added <code>finish()</code> method.
023 */
024public class FinishableServletOutputStream extends ServletOutputStream implements Finishable {
025
026   final OutputStream os;
027   final ServletOutputStream sos;
028   final Finishable f;
029   
030   FinishableServletOutputStream(OutputStream os) {
031      this.os = os;
032      this.sos = (os instanceof ServletOutputStream ? (ServletOutputStream)os : null);
033      this.f = (os instanceof Finishable ? (Finishable)os : null);
034   }
035   
036   @Override /* OutputStream */
037   public final void write(byte[] b, int off, int len) throws IOException {
038      os.write(b, off, len);
039   }
040   
041   @Override /* OutputStream */
042   public final void write(int b) throws IOException {
043      os.write(b);
044   }
045   
046   @Override /* OutputStream */
047   public final void flush() throws IOException {
048      os.flush();
049   }
050   
051   @Override /* OutputStream */
052   public final void close() throws IOException {
053      os.close();
054   }
055   
056   @Override /* ServletOutputStream */
057   public boolean isReady() {
058      return sos == null ? true : sos.isReady();
059   }
060   
061   @Override /* ServletOutputStream */
062   public void setWriteListener(WriteListener arg0) {
063      if (sos != null)
064         sos.setWriteListener(arg0);
065   }
066
067   /**
068    * Calls {@link Finishable#finish()} on the underlying output stream.
069    * 
070    * <p>
071    * A no-op if the underlying output stream does not implement the {@link Finishable} interface.
072    */
073   @Override /* Finishable */
074   public void finish() throws IOException {
075      if (f != null)
076         f.finish();
077   }
078}