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 static org.apache.juneau.commons.utils.Utils.*;
020
021import java.io.*;
022
023import org.apache.juneau.encoders.*;
024
025import jakarta.servlet.*;
026
027/**
028 * A wrapped {@link ServletOutputStream} with an added <c>finish()</c> method.
029 *
030 */
031public class FinishableServletOutputStream extends ServletOutputStream implements Finishable {
032
033   final OutputStream os;
034   final ServletOutputStream sos;
035   final Finishable f;
036
037   /**
038    * Constructor.
039    *
040    * @param os The wrapped output stream.
041    */
042   public FinishableServletOutputStream(OutputStream os) {
043      this.os = os;
044      this.sos = (os instanceof ServletOutputStream ? (ServletOutputStream)os : null);
045      this.f = (os instanceof Finishable ? (Finishable)os : null);
046   }
047
048   @Override /* Overridden from OutputStream */
049   public final void close() throws IOException {
050      os.close();
051   }
052
053   /**
054    * Calls {@link Finishable#finish()} on the underlying output stream.
055    *
056    * <p>
057    * A no-op if the underlying output stream does not implement the {@link Finishable} interface.
058    */
059   @Override /* Overridden from Finishable */
060   public void finish() throws IOException {
061      if (nn(f))
062         f.finish();
063   }
064
065   @Override /* Overridden from OutputStream */
066   public final void flush() throws IOException {
067      os.flush();
068   }
069
070   @Override /* Overridden from ServletOutputStream */
071   public boolean isReady() { return sos == null ? true : sos.isReady(); }
072
073   @Override /* Overridden from ServletOutputStream */
074   public void setWriteListener(WriteListener arg0) {
075      if (nn(sos))
076         sos.setWriteListener(arg0);
077   }
078
079   @Override /* Overridden from OutputStream */
080   public final void write(byte[] b, int off, int len) throws IOException {
081      os.write(b, off, len);
082   }
083
084   @Override /* Overridden from OutputStream */
085   public final void write(int b) throws IOException {
086      os.write(b);
087   }
088}