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.server.util;
018
019import static org.apache.juneau.commons.utils.Shorts.*;
020
021import java.io.*;
022
023import org.apache.juneau.marshall.encoders.*;
024
025import jakarta.servlet.*;
026
027/**
028 * A wrapped {@link ServletOutputStream} with an added <c>finish()</c> method.
029 *
030 */
031@SuppressWarnings({
032   "resource" // os and sos are servlet-container-managed streams passed in by the caller; closed by the container
033})
034public class FinishableServletOutputStream extends ServletOutputStream implements Finishable {
035
036   final OutputStream os;
037   final ServletOutputStream sos;
038   final Finishable f;
039
040   /**
041    * Constructor.
042    *
043    * @param os The wrapped output stream. Must not be <jk>null</jk>.
044    */
045   public FinishableServletOutputStream(OutputStream os) {
046      this.os = os;
047      this.sos = (os instanceof ServletOutputStream os2 ? os2 : null);
048      this.f = (os instanceof Finishable os2 ? os2 : null);
049   }
050
051   @Override /* Overridden from OutputStream */
052   public final void close() throws IOException {
053      os.close();
054   }
055
056   /**
057    * Calls {@link Finishable#finish()} on the underlying output stream.
058    *
059    * <p>
060    * A no-op if the underlying output stream does not implement the {@link Finishable} interface.
061    */
062   @Override /* Overridden from Finishable */
063   public void finish() throws IOException {
064      if (nn(f))
065         f.finish();
066   }
067
068   @Override /* Overridden from OutputStream */
069   public final void flush() throws IOException {
070      os.flush();
071   }
072
073   @Override /* Overridden from ServletOutputStream */
074   public boolean isReady() { return sos == null || sos.isReady(); }
075
076   @Override /* Overridden from ServletOutputStream */
077   public void setWriteListener(WriteListener arg0) {
078      if (nn(sos))
079         sos.setWriteListener(arg0);
080   }
081
082   @Override /* Overridden from OutputStream */
083   public final void write(byte[] b, int off, int len) throws IOException {
084      os.write(b, off, len);
085   }
086
087   @Override /* Overridden from OutputStream */
088   public final void write(int b) throws IOException {
089      os.write(b);
090   }
091}