blob: eebefc714238952929ce13008286e489c569ae2f (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
/*
* BodyObserver.java February 2007
*
* Copyright (C) 2007, Niall Gallagher <niallg@users.sf.net>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package org.simpleframework.http.core;
import org.simpleframework.transport.ByteWriter;
/**
* The <code>BodyObserver</code> object is core to how the requests
* are processed from a pipeline. This observes the progress of the
* response streams as they are written to the underlying transport
* which is typically TCP. If at any point there is an error in
* the delivery of the response the observer is notified. It can
* then shutdown the connection, as RFC 2616 suggests on errors.
* <p>
* If however the response is delivered successfully the monitor is
* notified of this event. On successful delivery the monitor will
* hand the <code>Channel</code> back to the server kernel so that
* the next request can be processed. This ensures ordering of the
* responses matches ordering of the requests.
*
* @author Niall Gallagher
*
* @see org.simpleframework.http.core.Controller
*/
interface BodyObserver {
/**
* This is used to close the underlying transport. A closure is
* typically done when the response is to a HTTP/1.0 client
* that does not require a keep alive connection. Also, if the
* container requests an explicit closure this is used when all
* of the content for the response has been sent.
*
* @param writer this is the writer used to send the response
*/
void close(ByteWriter writer);
/**
* This is used when there is an error sending the response. On
* error RFC 2616 suggests a connection closure is the best
* means to handle the condition, and the one clients should be
* expecting and support. All errors result in closure of the
* underlying transport and no more requests are processed.
*
* @param writer this is the writer used to send the response
*/
void error(ByteWriter writer);
/**
* This is used when the response has been sent correctly and
* the connection supports persisted HTTP. When ready the channel
* is handed back in to the server kernel where the next request
* on the pipeline is read and used to compose the next entity.
*
* @param writer this is the writer used to send the response
*/
void ready(ByteWriter writer);
/**
* This is used to notify the monitor that the HTTP response is
* committed and that the header can no longer be changed. It
* is also used to indicate whether the response can be reset.
*
* @param writer this is the writer used to send the response
*/
void commit(ByteWriter writer);
/**
* This can be used to determine whether the response has been
* committed. If the response is committed then the header can
* no longer be manipulated and the response has been partially
* send to the client.
*
* @return true if the response headers have been committed
*/
boolean isCommitted();
/**
* This is used to determine if the response has completed or
* if there has been an error. This basically allows the writer
* of the response to take action on certain I/O events.
*
* @return this returns true if there was an error or close
*/
boolean isClosed();
/**
* This is used to determine if the response was in error. If
* the response was in error this allows the writer to throw an
* exception indicating that there was a problem responding.
*
* @return this returns true if there was a response error
*/
boolean isError();
/**
* This represents the time at which the response was either
* ready, closed or in error. Providing a time here is useful
* as it allows the time taken to generate a response to be
* determined even if the response is written asynchronously.
*
* @return the time when the response completed or failed
*/
long getTime();
}
|
