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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  package org.apache.hc.core5.http.nio.entity;
28  
29  import java.io.IOException;
30  import java.io.UnsupportedEncodingException;
31  import java.nio.charset.Charset;
32  import java.nio.charset.StandardCharsets;
33  import java.nio.charset.UnsupportedCharsetException;
34  
35  import org.apache.hc.core5.concurrent.FutureCallback;
36  import org.apache.hc.core5.http.ContentType;
37  import org.apache.hc.core5.http.EntityDetails;
38  import org.apache.hc.core5.http.HttpException;
39  import org.apache.hc.core5.http.nio.AsyncEntityConsumer;
40  import org.apache.hc.core5.util.Args;
41  
42  /**
43   * @since 5.0
44   */
45  public abstract class AbstractCharAsyncEntityConsumer<T> extends AbstractCharDataConsumer implements AsyncEntityConsumer<T> {
46  
47      private volatile FutureCallback<T> resultCallback;
48      private volatile T content;
49  
50      protected abstract void streamStart(ContentType contentType) throws HttpException, IOException;
51  
52      protected abstract T generateContent() throws IOException;
53  
54      @Override
55      public final void streamStart(
56              final EntityDetails entityDetails,
57              final FutureCallback<T> resultCallback) throws IOException, HttpException {
58          Args.notNull(resultCallback, "Result callback");
59          this.resultCallback = resultCallback;
60          try {
61              final ContentType contentType = entityDetails != null ? ContentType.parse(entityDetails.getContentType()) : null;
62              Charset charset = contentType != null ? contentType.getCharset() : null;
63              if (charset == null) {
64                  charset = StandardCharsets.US_ASCII;
65              }
66              setCharset(charset);
67              streamStart(contentType);
68          } catch (final UnsupportedCharsetException ex) {
69              throw new UnsupportedEncodingException(ex.getMessage());
70          }
71      }
72  
73      @Override
74      protected final void completed() throws IOException {
75          content = generateContent();
76          if (resultCallback != null) {
77              resultCallback.completed(content);
78          }
79          releaseResources();
80      }
81  
82      @Override
83      public final void failed(final Exception cause) {
84          if (resultCallback != null) {
85              resultCallback.failed(cause);
86          }
87          releaseResources();
88      }
89  
90      @Override
91      public final T getContent() {
92          return content;
93      }
94  
95  }