CookieSyncManager.java revision eb9e801424005756f319d91493386b9a4f180921 
1/*
2 * Copyright (C) 2007 The Android Open Source Project
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 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
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
17package android.webkit;
18
19import android.content.Context;
20import android.util.Log;
21
22
23/**
24 * The CookieSyncManager is used to synchronize the browser cookie store
25 * between RAM and permanent storage. To get the best performance, browser cookies are
26 * saved in RAM. A separate thread saves the cookies between, driven by a timer.
27 * <p>
28 *
29 * To use the CookieSyncManager, the host application has to call the following
30 * when the application starts:
31 * <p>
32 *
33 * <pre class="prettyprint">CookieSyncManager.createInstance(context)</pre><p>
34 *
35 * To set up for sync, the host application has to call<p>
36 * <pre class="prettyprint">CookieSyncManager.getInstance().startSync()</pre><p>
37 *
38 * in Activity.onResume(), and call
39 * <p>
40 *
41 * <pre class="prettyprint">
42 * CookieSyncManager.getInstance().stopSync()
43 * </pre><p>
44 *
45 * in Activity.onPause().<p>
46 *
47 * To get instant sync instead of waiting for the timer to trigger, the host can
48 * call
49 * <p>
50 * <pre class="prettyprint">CookieSyncManager.getInstance().sync()</pre><p>
51 *
52 * The sync interval is 5 minutes, so you will want to force syncs
53 * manually anyway, for instance in {@link
54 * WebViewClient#onPageFinished}. Note that even sync() happens
55 * asynchronously, so don't do it just as your activity is shutting
56 * down.
57 */
58public final class CookieSyncManager extends WebSyncManager {
59
60    private static CookieSyncManager sRef;
61
62    private static boolean sGetInstanceAllowed = false;
63
64    private CookieSyncManager() {
65        super("CookieSyncManager");
66    }
67
68    /**
69     * Singleton access to a {@link CookieSyncManager}. An
70     * IllegalStateException will be thrown if
71     * {@link CookieSyncManager#createInstance(Context)} is not called before.
72     *
73     * @return CookieSyncManager
74     */
75    public static synchronized CookieSyncManager getInstance() {
76        checkInstanceIsAllowed();
77        if (sRef == null) {
78            sRef = new CookieSyncManager();
79        }
80        return sRef;
81    }
82
83    /**
84     * Create a singleton CookieSyncManager within a context
85     * @param context
86     * @return CookieSyncManager
87     */
88    public static synchronized CookieSyncManager createInstance(Context context) {
89        if (context == null) {
90            throw new IllegalArgumentException("Invalid context argument");
91        }
92
93        setGetInstanceIsAllowed();
94        return getInstance();
95    }
96
97    protected void syncFromRamToFlash() {
98        if (DebugFlags.COOKIE_SYNC_MANAGER) {
99            Log.v(LOGTAG, "CookieSyncManager::syncFromRamToFlash STARTS");
100        }
101
102        CookieManager manager = CookieManager.getInstance();
103
104        if (!manager.acceptCookie()) {
105            return;
106        }
107
108        manager.flushCookieStore();
109
110        if (DebugFlags.COOKIE_SYNC_MANAGER) {
111            Log.v(LOGTAG, "CookieSyncManager::syncFromRamToFlash DONE");
112        }
113    }
114
115    static void setGetInstanceIsAllowed() {
116        sGetInstanceAllowed = true;
117    }
118
119    private static void checkInstanceIsAllowed() {
120        // Prior to Android KK, calling createInstance() or constructing a WebView is
121        // a hard pre-condition for calling getInstance(). We retain that contract to aid
122        // developers targeting a range of SDK levels.
123        if (!sGetInstanceAllowed) {
124            throw new IllegalStateException(
125                    "CookieSyncManager::createInstance() needs to be called "
126                            + "before CookieSyncManager::getInstance()");
127        }
128    }
129}
130