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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 java.io.IOException;
31  
32  import org.apache.http.HttpException;
33  
34  /**
35   * Abstract server-side HTTP event handler.
36   *
37   * @since 4.2
38   */
39  public interface NHttpServerEventHandler {
40  
41      /**
42       * Triggered when a new incoming connection is created.
43       *
44       * @param conn new incoming connection HTTP connection.
45       */
46      void connected(
47              NHttpServerConnection conn) throws IOException, HttpException;
48  
49      /**
50       * Triggered when a new HTTP request is received. The connection
51       * passed as a parameter to this method is guaranteed to return
52       * a valid HTTP request object.
53       * <p/>
54       * If the request received encloses a request entity this method will
55       * be followed a series of
56       * {@link #inputReady(NHttpServerConnection, ContentDecoder)} calls
57       * to transfer the request content.
58       *
59       * @see NHttpServerConnection
60       *
61       * @param conn HTTP connection that contains a new HTTP request
62       */
63      void requestReceived(
64              NHttpServerConnection conn) throws IOException, HttpException;
65  
66      /**
67       * Triggered when the underlying channel is ready for reading a
68       * new portion of the request entity through the corresponding
69       * content decoder.
70       * <p/>
71       * If the content consumer is unable to process incoming content,
72       * input event notifications can be temporarily suspended using
73       * {@link IOControl} interface (super interface of {@link NHttpServerConnection}).
74       * <p/>
75       * Please note that the {@link NHttpServerConnection} and {@link ContentDecoder}
76       * objects are not thread-safe and should only be used within the context of
77       * this method call. The {@link IOControl} object can be shared and used on other
78       * thread to resume input event notifications when the handler is capable of
79       * processing more content.
80       *
81       * @see NHttpServerConnection
82       * @see ContentDecoder
83       * @see IOControl
84       *
85       * @param conn HTTP connection that can produce a new portion of the
86       * incoming request content.
87       * @param decoder The content decoder to use to read content.
88       */
89      void inputReady(
90              NHttpServerConnection conn,
91              ContentDecoder decoder) throws IOException, HttpException;
92  
93      /**
94       * Triggered when the connection is ready to accept a new HTTP response.
95       * The protocol handler does not have to submit a response if it is not
96       * ready.
97       *
98       * @see NHttpServerConnection
99       *
100      * @param conn HTTP connection that contains an HTTP response
101      */
102     void responseReady(
103             NHttpServerConnection conn) throws IOException, HttpException;
104 
105     /**
106      * Triggered when the underlying channel is ready for writing a
107      * next portion of the response entity through the corresponding
108      * content encoder.
109      * <p/>
110      * If the content producer is unable to generate outgoing content,
111      * output event notifications can be temporarily suspended using
112      * {@link IOControl} interface (super interface of {@link NHttpServerConnection}).
113      * <p/>
114      * Please note that the {@link NHttpServerConnection} and {@link ContentEncoder}
115      * objects are not thread-safe and should only be used within the context of
116      * this method call. The {@link IOControl} object can be shared and used on other
117      * thread to resume output event notifications when more content is made available.
118      *
119      * @see NHttpServerConnection
120      * @see ContentEncoder
121      * @see IOControl
122      *
123      * @param conn HTTP connection that can accommodate a new portion
124      * of the outgoing response content.
125      * @param encoder The content encoder to use to write content.
126      */
127     void outputReady(
128             NHttpServerConnection conn,
129             ContentEncoder encoder) throws IOException, HttpException;
130 
131     /**
132      * Triggered when the connection is closed by the opposite end point
133      * (half-closed).
134      *
135      * @param conn half-closed HTTP connection.
136      */
137     void endOfInput(
138             NHttpServerConnection conn) throws IOException;
139 
140     /**
141      * Triggered when no input is detected on this connection over the
142      * maximum period of inactivity.
143      *
144      * @param conn HTTP connection that caused timeout condition.
145      */
146     void timeout(
147             NHttpServerConnection conn) throws IOException;
148 
149     /**
150      * Triggered when the connection is closed.
151      *
152      * @param conn closed HTTP connection.
153      */
154     void closed(NHttpServerConnection conn);
155 
156     /**
157      * Triggered if an error occurs during the HTTP exchange.
158      *
159      * @param conn HTTP connection that caused an I/O error
160      * @param ex exception
161      */
162     void exception(NHttpServerConnection conn, Exception ex);
163 
164 }