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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.http.nio.entity;
29  
30  import java.io.IOException;
31  import java.io.InputStream;
32  import java.nio.ByteBuffer;
33  import java.nio.channels.Channels;
34  import java.nio.channels.ReadableByteChannel;
35  
36  import org.apache.http.HttpEntity;
37  import org.apache.http.nio.ContentEncoder;
38  import org.apache.http.nio.IOControl;
39  import org.apache.http.util.Args;
40  
41  /**
42   * Basic implementation of {@link HttpAsyncContentProducer} that relies on
43   * inefficient and potentially blocking I/O operation redirection through
44   * {@link Channels#newChannel(java.io.InputStream)}.
45   *
46   * @since 4.2
47   */
48  public class EntityAsyncContentProducer implements HttpAsyncContentProducer {
49  
50      private final HttpEntity entity;
51      private final ByteBuffer buffer;
52      private ReadableByteChannel channel;
53  
54      public EntityAsyncContentProducer(final HttpEntity entity) {
55          super();
56          Args.notNull(entity, "HTTP entity");
57          this.entity = entity;
58          this.buffer = ByteBuffer.allocate(4096);
59      }
60  
61      @Override
62      public void produceContent(
63              final ContentEncoder encoder, final IOControl ioctrl) throws IOException {
64          if (this.channel == null) {
65              this.channel = Channels.newChannel(this.entity.getContent());
66          }
67          final int i = this.channel.read(this.buffer);
68          this.buffer.flip();
69          encoder.write(this.buffer);
70          final boolean buffering = this.buffer.hasRemaining();
71          this.buffer.compact();
72          if (i == -1 && !buffering) {
73              encoder.complete();
74              close();
75          }
76      }
77  
78      @Override
79      public boolean isRepeatable() {
80          return this.entity.isRepeatable();
81      }
82  
83      @Override
84      public void close() throws IOException {
85          final ReadableByteChannel local = this.channel;
86          this.channel = null;
87          if (local != null) {
88              local.close();
89          }
90          if (this.entity.isStreaming()) {
91              final InputStream instream = this.entity.getContent();
92              instream.close();
93          }
94      }
95  
96      @Override
97      public String toString() {
98          return this.entity.toString();
99      }
100 
101 }