001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau.rest.util;
018
019import java.io.*;
020
021import org.apache.juneau.encoders.*;
022
023/**
024 * A wrapped {@link PrintWriter} with an added <c>finish()</c> method.
025 *
026 * <h5 class='section'>See Also:</h5><ul>
027 * </ul>
028 */
029public class FinishablePrintWriter extends PrintWriter implements Finishable {
030
031   final Finishable f;
032
033   /**
034    * Constructor.
035    *
036    * @param out The wrapped output stream.
037    * @param characterEncoding The character encoding of the output stream.
038    * @param autoFlush Automatically flush after every println.
039    * @throws IOException Thrown by underlying stream.
040    */
041   public FinishablePrintWriter(OutputStream out, String characterEncoding, boolean autoFlush) throws IOException {
042      super(new OutputStreamWriter(out, characterEncoding), autoFlush);
043      f = (out instanceof Finishable ? (Finishable)out : null);
044   }
045
046   /**
047    * Calls {@link Finishable#finish()} on the underlying output stream.
048    *
049    * <p>
050    * A no-op if the underlying output stream does not implement the {@link Finishable} interface.
051    */
052   @Override /* Finishable */
053   public void finish() throws IOException {
054      if (f != null)
055         f.finish();
056   }
057}