1 /*
2 * Copyright (c) 2002-2026 Gargoyle Software Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 * https://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15 package org.htmlunit;
16
17 import java.io.IOException;
18 import java.io.ObjectInputStream;
19 import java.lang.ref.WeakReference;
20
21 import org.apache.commons.logging.Log;
22 import org.apache.commons.logging.LogFactory;
23 import org.htmlunit.html.HtmlPage;
24
25 /**
26 * This {@link AjaxController} resynchronizes calls calling from the main thread.
27 * The idea is that asynchronous AJAX calls performed directly in response to a user
28 * action (therefore in the "main" thread and not in the thread of a background task)
29 * are directly useful for the user. To easily have a testable state, these calls
30 * are performed synchronously.
31 *
32 * @author Marc Guillemot
33 * @author Ronald Brill
34 */
35 public class NicelyResynchronizingAjaxController extends AjaxController {
36
37 private static final Log LOG = LogFactory.getLog(NicelyResynchronizingAjaxController.class);
38
39 private transient WeakReference<Thread> originatedThread_;
40
41 /**
42 * Creates an instance.
43 */
44 public NicelyResynchronizingAjaxController() {
45 super();
46 init();
47 }
48
49 /**
50 * Initializes this instance.
51 */
52 private void init() {
53 originatedThread_ = new WeakReference<>(Thread.currentThread());
54 }
55
56 /**
57 * Resynchronizes calls performed from the thread where this instance has been created.
58 * <p>
59 * {@inheritDoc}
60 */
61 @Override
62 public boolean processSynchron(final HtmlPage page, final WebRequest settings, final boolean async) {
63 if (async && isInOriginalThread()) {
64 LOG.info("Re-synchronized call to " + settings.getUrl());
65 return true;
66 }
67 return !async;
68 }
69
70 /**
71 * Indicates if the currently executing thread is the one in which this instance has been created.
72 * @return {@code true} if it's the same thread
73 */
74 boolean isInOriginalThread() {
75 return Thread.currentThread() == originatedThread_.get();
76 }
77
78 /**
79 * Custom deserialization logic.
80 * @param stream the stream from which to read the object
81 * @throws IOException if an IO error occurs
82 * @throws ClassNotFoundException if a class cannot be found
83 */
84 private void readObject(final ObjectInputStream stream) throws IOException, ClassNotFoundException {
85 stream.defaultReadObject();
86 init();
87 }
88
89 }