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 org.apache.juneau.encoders.*;
018
019/**
020 * A wrapped {@link PrintWriter} with an added <c>finish()</c> method.
021 *
022 * <h5 class='section'>See Also:</h5><ul>
023 * </ul>
024 */
025public class FinishablePrintWriter extends PrintWriter implements Finishable {
026
027   final Finishable f;
028
029   /**
030    * Constructor.
031    *
032    * @param out The wrapped output stream.
033    * @param characterEncoding The character encoding of the output stream.
034    * @param autoFlush Automatically flush after every println.
035    * @throws IOException Thrown by underlying stream.
036    */
037   public FinishablePrintWriter(OutputStream out, String characterEncoding, boolean autoFlush) throws IOException {
038      super(new OutputStreamWriter(out, characterEncoding), autoFlush);
039      f = (out instanceof Finishable ? (Finishable)out : null);
040   }
041
042   /**
043    * Calls {@link Finishable#finish()} on the underlying output stream.
044    *
045    * <p>
046    * A no-op if the underlying output stream does not implement the {@link Finishable} interface.
047    */
048   @Override /* Finishable */
049   public void finish() throws IOException {
050      if (f != null)
051         f.finish();
052   }
053}