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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  
28  package org.apache.hc.core5.http.impl.io;
29  
30  import java.io.IOException;
31  import java.io.OutputStream;
32  
33  import org.apache.hc.core5.http.StreamClosedException;
34  import org.apache.hc.core5.http.io.SessionOutputBuffer;
35  import org.apache.hc.core5.util.Args;
36  
37  /**
38   * Output stream that writes data without any transformation. The end of
39   * the content entity is demarcated by closing the underlying connection
40   * (EOF condition). Entities transferred using this input stream can be of
41   * unlimited length.
42   * <p>
43   * Note that this class NEVER closes the underlying stream, even when close
44   * gets called.  Instead, the stream will be marked as closed and no further
45   * output will be permitted.
46   *
47   * @since 4.0
48   */
49  public class IdentityOutputStream extends OutputStream {
50  
51      private final SessionOutputBuffer buffer;
52      private final OutputStream outputStream;
53  
54      /** True if the stream is closed. */
55      private boolean closed = false;
56  
57      /**
58       * Default constructor.
59       *
60       * @param buffer Session output buffer
61       * @param outputStream Output stream
62       */
63      public IdentityOutputStream(final SessionOutputBuffer buffer, final OutputStream outputStream) {
64          super();
65          this.buffer = Args.notNull(buffer, "Session output buffer");
66          this.outputStream = Args.notNull(outputStream, "Output stream");
67      }
68  
69      /**
70       * <p>Does not close the underlying socket output.</p>
71       *
72       * @throws IOException If an I/O problem occurs.
73       */
74      @Override
75      public void close() throws IOException {
76          if (!this.closed) {
77              this.closed = true;
78              this.buffer.flush(this.outputStream);
79          }
80      }
81  
82      @Override
83      public void flush() throws IOException {
84          this.buffer.flush(this.outputStream);
85      }
86  
87      @Override
88      public void write(final byte[] b, final int off, final int len) throws IOException {
89          if (this.closed) {
90              throw new StreamClosedException("Stream already closed");
91          }
92          this.buffer.write(b, off, len, this.outputStream);
93      }
94  
95      @Override
96      public void write(final byte[] b) throws IOException {
97          write(b, 0, b.length);
98      }
99  
100     @Override
101     public void write(final int b) throws IOException {
102         if (this.closed) {
103             throw new StreamClosedException("Stream already closed");
104         }
105         this.buffer.write(b, this.outputStream);
106     }
107 
108 }