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.util;
014
015import java.io.*;
016
017import javax.servlet.*;
018
019import org.apache.juneau.encoders.*;
020
021/**
022 * A wrapped {@link ServletOutputStream} with an added <c>finish()</c> method.
023 */
024public class FinishableServletOutputStream extends ServletOutputStream implements Finishable {
025
026   final OutputStream os;
027   final ServletOutputStream sos;
028   final Finishable f;
029
030   /**
031    * Constructor.
032    *
033    * @param os The wrapped output stream.
034    */
035   public FinishableServletOutputStream(OutputStream os) {
036      this.os = os;
037      this.sos = (os instanceof ServletOutputStream ? (ServletOutputStream)os : null);
038      this.f = (os instanceof Finishable ? (Finishable)os : null);
039   }
040
041   @Override /* OutputStream */
042   public final void write(byte[] b, int off, int len) throws IOException {
043      os.write(b, off, len);
044   }
045
046   @Override /* OutputStream */
047   public final void write(int b) throws IOException {
048      os.write(b);
049   }
050
051   @Override /* OutputStream */
052   public final void flush() throws IOException {
053      os.flush();
054   }
055
056   @Override /* OutputStream */
057   public final void close() throws IOException {
058      os.close();
059   }
060
061   @Override /* ServletOutputStream */
062   public boolean isReady() {
063      return sos == null ? true : sos.isReady();
064   }
065
066   @Override /* ServletOutputStream */
067   public void setWriteListener(WriteListener arg0) {
068      if (sos != null)
069         sos.setWriteListener(arg0);
070   }
071
072   /**
073    * Calls {@link Finishable#finish()} on the underlying output stream.
074    *
075    * <p>
076    * A no-op if the underlying output stream does not implement the {@link Finishable} interface.
077    */
078   @Override /* Finishable */
079   public void finish() throws IOException {
080      if (f != null)
081         f.finish();
082   }
083}