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
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
|
/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package ch.boye.httpclientandroidlib.protocol;
import java.io.IOException;
import ch.boye.httpclientandroidlib.HttpClientConnection;
import ch.boye.httpclientandroidlib.HttpEntityEnclosingRequest;
import ch.boye.httpclientandroidlib.HttpException;
import ch.boye.httpclientandroidlib.HttpRequest;
import ch.boye.httpclientandroidlib.HttpResponse;
import ch.boye.httpclientandroidlib.HttpStatus;
import ch.boye.httpclientandroidlib.HttpVersion;
import ch.boye.httpclientandroidlib.ProtocolException;
import ch.boye.httpclientandroidlib.ProtocolVersion;
import ch.boye.httpclientandroidlib.annotation.Immutable;
import ch.boye.httpclientandroidlib.util.Args;
/**
* <tt>HttpRequestExecutor</tt> is a client side HTTP protocol handler based
* on the blocking (classic) I/O model.
* <p/>
* <tt>HttpRequestExecutor</tt> relies on {@link HttpProcessor} to generate
* mandatory protocol headers for all outgoing messages and apply common,
* cross-cutting message transformations to all incoming and outgoing messages.
* Application specific processing can be implemented outside
* <tt>HttpRequestExecutor</tt> once the request has been executed and
* a response has been received.
*
* @since 4.0
*/
@Immutable
public class HttpRequestExecutor {
public static final int DEFAULT_WAIT_FOR_CONTINUE = 3000;
private final int waitForContinue;
/**
* Creates new instance of HttpRequestExecutor.
*
* @since 4.3
*/
public HttpRequestExecutor(final int waitForContinue) {
super();
this.waitForContinue = Args.positive(waitForContinue, "Wait for continue time");
}
public HttpRequestExecutor() {
this(DEFAULT_WAIT_FOR_CONTINUE);
}
/**
* Decide whether a response comes with an entity.
* The implementation in this class is based on RFC 2616.
* <br/>
* Derived executors can override this method to handle
* methods and response codes not specified in RFC 2616.
*
* @param request the request, to obtain the executed method
* @param response the response, to obtain the status code
*/
protected boolean canResponseHaveBody(final HttpRequest request,
final HttpResponse response) {
if ("HEAD".equalsIgnoreCase(request.getRequestLine().getMethod())) {
return false;
}
final int status = response.getStatusLine().getStatusCode();
return status >= HttpStatus.SC_OK
&& status != HttpStatus.SC_NO_CONTENT
&& status != HttpStatus.SC_NOT_MODIFIED
&& status != HttpStatus.SC_RESET_CONTENT;
}
/**
* Sends the request and obtain a response.
*
* @param request the request to execute.
* @param conn the connection over which to execute the request.
*
* @return the response to the request.
*
* @throws IOException in case of an I/O error.
* @throws HttpException in case of HTTP protocol violation or a processing
* problem.
*/
public HttpResponse execute(
final HttpRequest request,
final HttpClientConnection conn,
final HttpContext context) throws IOException, HttpException {
Args.notNull(request, "HTTP request");
Args.notNull(conn, "Client connection");
Args.notNull(context, "HTTP context");
try {
HttpResponse response = doSendRequest(request, conn, context);
if (response == null) {
response = doReceiveResponse(request, conn, context);
}
return response;
} catch (final IOException ex) {
closeConnection(conn);
throw ex;
} catch (final HttpException ex) {
closeConnection(conn);
throw ex;
} catch (final RuntimeException ex) {
closeConnection(conn);
throw ex;
}
}
private static void closeConnection(final HttpClientConnection conn) {
try {
conn.close();
} catch (final IOException ignore) {
}
}
/**
* Pre-process the given request using the given protocol processor and
* initiates the process of request execution.
*
* @param request the request to prepare
* @param processor the processor to use
* @param context the context for sending the request
*
* @throws IOException in case of an I/O error.
* @throws HttpException in case of HTTP protocol violation or a processing
* problem.
*/
public void preProcess(
final HttpRequest request,
final HttpProcessor processor,
final HttpContext context) throws HttpException, IOException {
Args.notNull(request, "HTTP request");
Args.notNull(processor, "HTTP processor");
Args.notNull(context, "HTTP context");
context.setAttribute(HttpCoreContext.HTTP_REQUEST, request);
processor.process(request, context);
}
/**
* Send the given request over the given connection.
* <p>
* This method also handles the expect-continue handshake if necessary.
* If it does not have to handle an expect-continue handshake, it will
* not use the connection for reading or anything else that depends on
* data coming in over the connection.
*
* @param request the request to send, already
* {@link #preProcess preprocessed}
* @param conn the connection over which to send the request,
* already established
* @param context the context for sending the request
*
* @return a terminal response received as part of an expect-continue
* handshake, or
* <code>null</code> if the expect-continue handshake is not used
*
* @throws IOException in case of an I/O error.
* @throws HttpException in case of HTTP protocol violation or a processing
* problem.
*/
protected HttpResponse doSendRequest(
final HttpRequest request,
final HttpClientConnection conn,
final HttpContext context) throws IOException, HttpException {
Args.notNull(request, "HTTP request");
Args.notNull(conn, "Client connection");
Args.notNull(context, "HTTP context");
HttpResponse response = null;
context.setAttribute(HttpCoreContext.HTTP_CONNECTION, conn);
context.setAttribute(HttpCoreContext.HTTP_REQ_SENT, Boolean.FALSE);
conn.sendRequestHeader(request);
if (request instanceof HttpEntityEnclosingRequest) {
// Check for expect-continue handshake. We have to flush the
// headers and wait for an 100-continue response to handle it.
// If we get a different response, we must not send the entity.
boolean sendentity = true;
final ProtocolVersion ver =
request.getRequestLine().getProtocolVersion();
if (((HttpEntityEnclosingRequest) request).expectContinue() &&
!ver.lessEquals(HttpVersion.HTTP_1_0)) {
conn.flush();
// As suggested by RFC 2616 section 8.2.3, we don't wait for a
// 100-continue response forever. On timeout, send the entity.
if (conn.isResponseAvailable(this.waitForContinue)) {
response = conn.receiveResponseHeader();
if (canResponseHaveBody(request, response)) {
conn.receiveResponseEntity(response);
}
final int status = response.getStatusLine().getStatusCode();
if (status < 200) {
if (status != HttpStatus.SC_CONTINUE) {
throw new ProtocolException(
"Unexpected response: " + response.getStatusLine());
}
// discard 100-continue
response = null;
} else {
sendentity = false;
}
}
}
if (sendentity) {
conn.sendRequestEntity((HttpEntityEnclosingRequest) request);
}
}
conn.flush();
context.setAttribute(HttpCoreContext.HTTP_REQ_SENT, Boolean.TRUE);
return response;
}
/**
* Waits for and receives a response.
* This method will automatically ignore intermediate responses
* with status code 1xx.
*
* @param request the request for which to obtain the response
* @param conn the connection over which the request was sent
* @param context the context for receiving the response
*
* @return the terminal response, not yet post-processed
*
* @throws IOException in case of an I/O error.
* @throws HttpException in case of HTTP protocol violation or a processing
* problem.
*/
protected HttpResponse doReceiveResponse(
final HttpRequest request,
final HttpClientConnection conn,
final HttpContext context) throws HttpException, IOException {
Args.notNull(request, "HTTP request");
Args.notNull(conn, "Client connection");
Args.notNull(context, "HTTP context");
HttpResponse response = null;
int statusCode = 0;
while (response == null || statusCode < HttpStatus.SC_OK) {
response = conn.receiveResponseHeader();
if (canResponseHaveBody(request, response)) {
conn.receiveResponseEntity(response);
}
statusCode = response.getStatusLine().getStatusCode();
} // while intermediate response
return response;
}
/**
* Post-processes the given response using the given protocol processor and
* completes the process of request execution.
* <p>
* This method does <i>not</i> read the response entity, if any.
* The connection over which content of the response entity is being
* streamed from cannot be reused until
* {@link ch.boye.httpclientandroidlib.util.EntityUtils#consume(ch.boye.httpclientandroidlib.HttpEntity)}
* has been invoked.
*
* @param response the response object to post-process
* @param processor the processor to use
* @param context the context for post-processing the response
*
* @throws IOException in case of an I/O error.
* @throws HttpException in case of HTTP protocol violation or a processing
* problem.
*/
public void postProcess(
final HttpResponse response,
final HttpProcessor processor,
final HttpContext context) throws HttpException, IOException {
Args.notNull(response, "HTTP response");
Args.notNull(processor, "HTTP processor");
Args.notNull(context, "HTTP context");
context.setAttribute(HttpCoreContext.HTTP_RESPONSE, response);
processor.process(response, context);
}
} // class HttpRequestExecutor
|