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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;
29  
30  import org.apache.http.HttpConnection;
31  import org.apache.http.HttpRequest;
32  import org.apache.http.HttpResponse;
33  import org.apache.http.protocol.HttpContext;
34  
35  /**
36   * Abstract non-blocking HTTP connection interface. Each connection contains an
37   * HTTP execution context, which can be used to maintain a processing state,
38   * as well as the actual {@link HttpRequest} and {@link HttpResponse} that are
39   * being transmitted over this connection. Both the request and
40   * the response objects can be <code>null</code> if there is no incoming or
41   * outgoing message currently being transferred.
42   * <p>
43   * Please note non-blocking HTTP connections are stateful and not thread safe.
44   * Input / output operations on non-blocking HTTP connections should be
45   * restricted to the dispatch events triggered by the I/O event dispatch thread.
46   * However, the {@link IOControl} interface is fully threading safe and can be
47   * manipulated from any thread.
48   *
49   * @since 4.0
50   */
51  public interface NHttpConnection extends HttpConnection, IOControl {
52  
53      public static final int ACTIVE      = 0;
54      public static final int CLOSING     = 1;
55      public static final int CLOSED      = 2;
56  
57      /**
58       * Returns status of the connection:
59       * <p>
60       * {@link #ACTIVE}: connection is active.
61       * <p>
62       * {@link #CLOSING}: connection is being closed.
63       * <p>
64       * {@link #CLOSED}: connection has been closed.
65       *
66       * @return connection status.
67       */
68      int getStatus();
69  
70      /**
71       * Returns the current HTTP request if one is being received / transmitted.
72       * Otherwise returns <code>null</code>.
73       *
74       * @return HTTP request, if available, <code>null</code> otherwise.
75       */
76      HttpRequest getHttpRequest();
77  
78      /**
79       * Returns the current HTTP response if one is being received / transmitted.
80       * Otherwise returns <tt>null</tt>.
81       *
82       * @return HTTP response, if available, <code>null</code> otherwise.
83       */
84      HttpResponse getHttpResponse();
85  
86      /**
87       * Returns an HTTP execution context associated with this connection.
88       * @return HTTP context
89       */
90      HttpContext getContext();
91  
92  }