01: /*
02: * Copyright 2002-2007 the original author or authors.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16:
17: package org.springframework.web.context.request;
18:
19: import java.util.Iterator;
20: import java.util.LinkedHashMap;
21: import java.util.Map;
22:
23: import org.springframework.util.Assert;
24:
25: /**
26: * Abstract support class for RequestAttributes implementations,
27: * offering a request completion mechanism for request-specific destruction
28: * callbacks and for updating accessed session attributes.
29: *
30: * @author Juergen Hoeller
31: * @since 2.0
32: * @see #requestCompleted()
33: */
34: public abstract class AbstractRequestAttributes implements
35: RequestAttributes {
36:
37: /** Map from attribute name String to destruction callback Runnable */
38: protected final Map requestDestructionCallbacks = new LinkedHashMap(
39: 8);
40:
41: /**
42: * Signal that the request has been completed.
43: * <p>Executes all request destruction callbacks and updates the
44: * session attributes that have been accessed during request processing.
45: */
46: public void requestCompleted() {
47: executeRequestDestructionCallbacks();
48: updateAccessedSessionAttributes();
49: }
50:
51: /**
52: * Register the given callback as to be executed after request completion.
53: * @param name the name of the attribute to register the callback for
54: * @param callback the callback to be executed for destruction
55: */
56: protected final void registerRequestDestructionCallback(
57: String name, Runnable callback) {
58: Assert.notNull(name, "Name must not be null");
59: Assert.notNull(callback, "Callback must not be null");
60: this .requestDestructionCallbacks.put(name, callback);
61: }
62:
63: /**
64: * Remove the request destruction callback for the specified attribute, if any.
65: * @param name the name of the attribute to remove the callback for
66: */
67: protected final void removeRequestDestructionCallback(String name) {
68: Assert.notNull(name, "Name must not be null");
69: this .requestDestructionCallbacks.remove(name);
70: }
71:
72: /**
73: * Execute all callbacks that have been registered for execution
74: * after request completion.
75: */
76: private void executeRequestDestructionCallbacks() {
77: for (Iterator it = this .requestDestructionCallbacks.values()
78: .iterator(); it.hasNext();) {
79: ((Runnable) it.next()).run();
80: }
81: this .requestDestructionCallbacks.clear();
82: }
83:
84: /**
85: * Update all session attributes that have been accessed during request processing,
86: * to expose their potentially updated state to the underlying session manager.
87: */
88: protected abstract void updateAccessedSessionAttributes();
89:
90: }
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