android上WebView设置cookie,以及设置webview cookie在部分手机失效

这是在网上抄的cookie设置方案,在android 5.0系统上测试时正常在，在部分4.X手机上测试有时会失效

（我使用的测试机为中兴  ZTE android版本4.3 ）

 public void cookie(Context context,String url,String value) {

        try {
            CookieSyncManager.createInstance(context);
            CookieManager cookieManager = CookieManager.getInstance();
            cookieManager.setAcceptCookie(true);
            cookieManager.removeSessionCookie();
            cookieManager.setCookie(url,value);
            CookieSyncManager.getInstance().sync();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

最终解决方案是

http://code.walletapp.net/post/46414301269/passing-cookie-to-webview

但是解决问题的人回答是

In few following lines I will describe my solution, how to pass cookies from DefaultHttpClient to WebView component. I was following many tutorials, but cookies weren’t send to WebView properly (in my Android 2.2). After several experiments I found out that it is working, when we wait a little time between removeSessionCookie and setCookie methods. I don’t know why. But important is, that it is working right now for me.

在removeSessionCookie和setCookie方法之间需要加入等待时间，设置cookie成功，但是不知道为什么。

解决方案是等待了1000毫秒，实际应该不需要这么长的时间

我们去android 源码在线网站上看看

http://grepcode.com/project/repository.grepcode.com/java/ext/com.google.android/android/

在android 4.0上removeSeesionCookie的代码  开启了AsyncTask的异步任务处理cookie。也就是说removeSeesionCookie这段代码是在4.0的系统上异步的

所以cookieManager.removeSeesionCookie()  异步会导致删除setcookie的内容，所以有时成功有时失败

public void More ...removeSessionCookie() {
610         signalCookieOperationsStart();//某个变量值+1
611         if (JniUtil.useChromiumHttpStack()) {
612             new AsyncTask<Void, Void, Void>() {
613                 protected Void More ...doInBackground(Void... none) {
614                     nativeRemoveSessionCookie();  //移除本地所有会话的cookie
615                     signalCookieOperationsComplete();//某个变量值-1 并断言 相当于log
616                     return null;
617                 }
618             }.execute();//启动异步任务
619             return;
620         }
621 
622         final Runnable clearCache = new Runnable() {
623             public void More ...run() {
624                 synchronized(CookieManager.this) {   //移除所有内存中的cookie映射
625                     Collection<ArrayList<Cookie>> cookieList = mCookieMap.values();
626                     Iterator<ArrayList<Cookie>> listIter = cookieList.iterator();
627                     while (listIter.hasNext()) {
628                         ArrayList<Cookie> list = listIter.next();
629                         Iterator<Cookie> iter = list.iterator();
630                         while (iter.hasNext()) {
631                             Cookie cookie = iter.next();
632                             if (cookie.expires == -1) {
633                                 iter.remove();
634                             }
635                         }
636                     }
637                     CookieSyncManager.getInstance().clearSessionCookies();//清空所有会话的cookie
638                     signalCookieOperationsComplete();
639                 }
640             }
641         };
642         new Thread(clearCache).start();//启动线程
643     }

另外4.X的CookieManager的sync()也是异步的  以下是代码段

开启一个mHandler（SyncHandler）等待100毫秒 调用 syncFlushCookieStor()->flushCookieStore()->nativeFlushCookieStore() （这句才是真正将cookiet同步的代码）

public void More ...sync() {
97         if (DebugFlags.WEB_SYNC_MANAGER) {
98             Log.v(LOGTAG, "*** WebSyncManager sync ***");
99         }
100        if (mHandler == null) {
101            return;
102        }
103        mHandler.removeMessages(SYNC_MESSAGE);
104        Message msg = mHandler.obtainMessage(SYNC_MESSAGE);
105        mHandler.sendMessageDelayed(msg, SYNC_NOW_INTERVAL); //等待<span style="font-family: 'Lucida Grande', Tahoma, Verdana, Arial, Helvetica, sans-serif;">SYNC_NOW_INTERVAL=</span><span style="font-family: 'Lucida Grande', Tahoma, Verdana, Arial, Helvetica, sans-serif;">100毫秒</span>
106    }

private class More ...SyncHandler extends Handler {
47         @Override
48         public void More ...handleMessage(Message msg) {
49             if (msg.what == SYNC_MESSAGE) {
50                 if (DebugFlags.WEB_SYNC_MANAGER) {
51                     Log.v(LOGTAG, "*** WebSyncManager sync ***");
52                 }
53                 syncFromRamToFlash();
54 
55                 // send a delayed message to request sync later
56                 Message newmsg = obtainMessage(SYNC_MESSAGE);
57                 sendMessageDelayed(newmsg, SYNC_LATER_INTERVAL);
58             }
59         }
60     }

protected void More ...syncFromRamToFlash() {
         if (DebugFlags.COOKIE_SYNC_MANAGER) {
             Log.v(LOGTAG, "CookieSyncManager::syncFromRamToFlash STARTS");
        }

        CookieManager manager = CookieManager.getInstance();

        if (!manager.acceptCookie()) {
            return;
        }

        manager.flushCookieStore();

        if (DebugFlags.COOKIE_SYNC_MANAGER) {
            Log.v(LOGTAG, "CookieSyncManager::syncFromRamToFlash DONE");
        }
    }

在android5.0系统上Sync回调用flush()方法

 @Deprecated
115    protected void More ...syncFromRamToFlash() {
116        CookieManager.getInstance().flush();
117    }

另外android 5.0官方文档上面也说明了

The WebView now automatically syncs cookies as necessary. You no longer need to create or use the CookieSyncManager. To manually force a sync you can use the CookieManager methodCookieManager.flush() which is a synchronous replacement for sync().

webview现在必须自动同步cookie，你不再需要创建或使用cookiesyncmanager，你可以使用CookieManager的CookieManager.flush()方法，flush()是sync()同步置换

结论在android4.X系统下面cookiesyncmanager的方法有些事异步的，removeSeesionCookie()和sync()要等待100毫秒。

而在android5.0以上的系统Cookie是同步的,sync=flush方法，调用CookieManager.flush()就是同步设置cookie。