Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
AbstractReceiverWorker |
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AbstractReceiverWorker$1 |
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1 | /* | |
2 | * $Id: AbstractReceiverWorker.java 20498 2010-12-08 00:27:08Z tcarlson $ | |
3 | * -------------------------------------------------------------------------------------- | |
4 | * Copyright (c) MuleSoft, Inc. All rights reserved. http://www.mulesoft.com | |
5 | * | |
6 | * The software in this package is published under the terms of the CPAL v1.0 | |
7 | * license, a copy of which has been included with this distribution in the | |
8 | * LICENSE.txt file. | |
9 | */ | |
10 | package org.mule.transport; | |
11 | ||
12 | import org.mule.api.MessagingException; | |
13 | import org.mule.api.MuleContext; | |
14 | import org.mule.api.MuleEvent; | |
15 | import org.mule.api.MuleMessage; | |
16 | import org.mule.api.MuleSession; | |
17 | import org.mule.api.endpoint.InboundEndpoint; | |
18 | import org.mule.api.transaction.Transaction; | |
19 | import org.mule.api.transaction.TransactionCallback; | |
20 | import org.mule.api.transaction.TransactionException; | |
21 | import org.mule.api.transport.SessionHandler; | |
22 | import org.mule.session.LegacySessionHandler; | |
23 | import org.mule.session.MuleSessionHandler; | |
24 | import org.mule.transaction.TransactionCoordination; | |
25 | import org.mule.transaction.TransactionTemplate; | |
26 | ||
27 | import java.io.OutputStream; | |
28 | import java.util.ArrayList; | |
29 | import java.util.List; | |
30 | ||
31 | import javax.resource.spi.work.Work; | |
32 | ||
33 | import org.apache.commons.lang.SerializationException; | |
34 | ||
35 | /** | |
36 | * A base Worker used by Transport {@link org.mule.api.transport.MessageReceiver} implementations. | |
37 | */ | |
38 | public abstract class AbstractReceiverWorker implements Work | |
39 | { | |
40 | protected List<Object> messages; | |
41 | protected InboundEndpoint endpoint; | |
42 | protected AbstractMessageReceiver receiver; | |
43 | protected OutputStream out; | |
44 | ||
45 | public AbstractReceiverWorker(List<Object> messages, AbstractMessageReceiver receiver) | |
46 | { | |
47 | 0 | this(messages, receiver, null); |
48 | 0 | } |
49 | ||
50 | public AbstractReceiverWorker(List<Object> messages, AbstractMessageReceiver receiver, OutputStream out) | |
51 | 0 | { |
52 | 0 | this.messages = messages; |
53 | 0 | this.receiver = receiver; |
54 | 0 | this.endpoint = receiver.getEndpoint(); |
55 | 0 | this.out = out; |
56 | 0 | } |
57 | ||
58 | /** | |
59 | * This will run the receiver logic and call {@link #release()} once {@link #doRun()} completes. | |
60 | * | |
61 | */ | |
62 | public final void run() | |
63 | { | |
64 | 0 | doRun(); |
65 | 0 | release(); |
66 | 0 | } |
67 | ||
68 | /** | |
69 | * The actual logic used to receive messages from the underlying transport. The default implementation | |
70 | * will execute the processing of messages within a TransactionTemplate. This template will manage the | |
71 | * transaction lifecycle for the list of messages associated with this receiver worker. | |
72 | */ | |
73 | protected void doRun() | |
74 | { | |
75 | // MuleContext is used down the line for | |
76 | // getTransactionManager() (XaTransactionFactory) and getQueueManager() (VMTransaction) | |
77 | 0 | final MuleContext muleContext = receiver.getConnector().getMuleContext(); |
78 | 0 | TransactionTemplate tt = new TransactionTemplate(endpoint.getTransactionConfig(), muleContext); |
79 | ||
80 | // Receive messages and process them in a single transaction | |
81 | // Do not enable threading here, but serveral workers | |
82 | // may have been started | |
83 | 0 | TransactionCallback<?> cb = new TransactionCallback() |
84 | 0 | { |
85 | public Object doInTransaction() throws Exception | |
86 | { | |
87 | 0 | Transaction tx = TransactionCoordination.getInstance().getTransaction(); |
88 | 0 | if (tx != null) |
89 | { | |
90 | 0 | bindTransaction(tx); |
91 | } | |
92 | 0 | List<Object> results = new ArrayList<Object>(messages.size()); |
93 | ||
94 | 0 | for (Object payload : messages) |
95 | { | |
96 | 0 | payload = preProcessMessage(payload); |
97 | 0 | if (payload != null) |
98 | { | |
99 | 0 | MuleMessage muleMessage = receiver.createMuleMessage(payload, endpoint.getEncoding()); |
100 | 0 | preRouteMuleMessage(muleMessage); |
101 | ||
102 | // TODO Move getSessionHandler() to the Connector interface | |
103 | SessionHandler handler; | |
104 | 0 | if (endpoint.getConnector() instanceof AbstractConnector) |
105 | { | |
106 | 0 | handler = ((AbstractConnector) endpoint.getConnector()).getSessionHandler(); |
107 | } | |
108 | else | |
109 | { | |
110 | 0 | handler = new MuleSessionHandler(); |
111 | } | |
112 | MuleSession session; | |
113 | try | |
114 | { | |
115 | 0 | session = handler.retrieveSessionInfoFromMessage(muleMessage); |
116 | } | |
117 | 0 | catch (SerializationException e) |
118 | { | |
119 | // EE-1820 Support message headers generated by previous Mule versions | |
120 | 0 | session = new LegacySessionHandler().retrieveSessionInfoFromMessage(muleMessage); |
121 | 0 | } |
122 | ||
123 | MuleEvent resultEvent; | |
124 | 0 | if (session != null) |
125 | { | |
126 | 0 | resultEvent = receiver.routeMessage(muleMessage, session, tx, out); |
127 | } | |
128 | else | |
129 | { | |
130 | 0 | resultEvent = receiver.routeMessage(muleMessage, tx, out); |
131 | } | |
132 | 0 | MuleMessage result = resultEvent == null ? null : resultEvent.getMessage(); |
133 | 0 | if (result != null) |
134 | { | |
135 | 0 | payload = postProcessMessage(result); |
136 | 0 | if (payload != null) |
137 | { | |
138 | 0 | results.add(payload); |
139 | } | |
140 | } | |
141 | 0 | } |
142 | } | |
143 | 0 | return results; |
144 | } | |
145 | }; | |
146 | ||
147 | try | |
148 | { | |
149 | 0 | List results = (List) tt.execute(cb); |
150 | 0 | handleResults(results); |
151 | } | |
152 | 0 | catch (MessagingException e) |
153 | { | |
154 | 0 | receiver.getFlowConstruct().getExceptionListener().handleException(e, e.getEvent()); |
155 | } | |
156 | 0 | catch (Exception e) |
157 | { | |
158 | 0 | muleContext.getExceptionListener().handleException(e); |
159 | } | |
160 | finally | |
161 | { | |
162 | 0 | messages.clear(); |
163 | 0 | } |
164 | 0 | } |
165 | ||
166 | /** | |
167 | * This callback is called before a message is routed into Mule and can be used by the worker to set connection | |
168 | * specific properties to message before it gets routed | |
169 | * | |
170 | * @param message the next message to be processed | |
171 | * @throws Exception | |
172 | */ | |
173 | protected void preRouteMuleMessage(MuleMessage message) throws Exception | |
174 | { | |
175 | //no op | |
176 | 0 | } |
177 | ||
178 | /** | |
179 | * Template method used to bind the resources of this receiver to the transaction. Only transactional | |
180 | * transports need implment this method | |
181 | * @param tx the current transaction or null if there is no transaction | |
182 | * @throws TransactionException | |
183 | */ | |
184 | protected abstract void bindTransaction(Transaction tx) throws TransactionException; | |
185 | ||
186 | /** | |
187 | * When Mule has finished processing the current messages, there may be zero or more messages to process | |
188 | * by the receiver if request/response messaging is being used. The result(s) should be passed back to the callee. | |
189 | * @param messages a list of messages. This argument will not be null | |
190 | * @throws Exception | |
191 | */ | |
192 | protected void handleResults(List messages) throws Exception | |
193 | { | |
194 | //no op | |
195 | 0 | } |
196 | ||
197 | /** | |
198 | * Before a message is passed into Mule this callback is called and can be used by the worker to inspect the | |
199 | * message before it gets sent to Mule | |
200 | * @param message the next message to be processed | |
201 | * @return the message to be processed. If Null is returned the message will not get processed. | |
202 | * @throws Exception | |
203 | */ | |
204 | protected Object preProcessMessage(Object message) throws Exception | |
205 | { | |
206 | //no op | |
207 | 0 | return message; |
208 | } | |
209 | ||
210 | /** | |
211 | * If a result is returned back this method will get called before the message is added to te list of | |
212 | * results (these are later passed to {@link #handleResults(java.util.List)}) | |
213 | * @param message the result message, this will never be null | |
214 | * @return the message to add to the list of results. If null is returned nothing is added to the | |
215 | * list of results | |
216 | * @throws Exception | |
217 | */ | |
218 | protected MuleMessage postProcessMessage(MuleMessage message) throws Exception | |
219 | { | |
220 | //no op | |
221 | 0 | return message; |
222 | } | |
223 | ||
224 | ||
225 | /** | |
226 | * This method is called once this worker is no longer required. Any resources *only* associated with | |
227 | * this worker should be cleaned up here. | |
228 | */ | |
229 | public void release() | |
230 | { | |
231 | // no op | |
232 | 0 | } |
233 | } |