Problem calling AsyncTask obj other time - Android_问答_开发者

In my Activity class implements UINotifier that is used to notify the Activity class on call of a TimerTask object. In my doInBackground(), I call my function located in ASyncTask class (connectTask) only. onPostExecute is executed and in last, I call a method "ReConnect()" that is located in my Activity class. The code and its flow is :

// OF Interface UINotifier
@Override
public void notifyUI() {
    Log.i(TAG, "GOT MESSAGE FROM MonitorConnection");
    monitorTimer.cancel();
    Log.i(TAG, "Preparing to Start");
    PrepareToStartToConnect();
    //publishProgress(4);
    int status = 1;
    if (status == 1 || status == 2)
        ReConnect();
}

// Called on "Connect" button
private void ConnectClicked() {
    Log.i(TAG, "Inside Connectclicked");
    if (isConnectEligeble()) {
        Log.i(TAG, "isConnectionEligible = true");
        currentState= CONNECTING;
        connectTask = new ConnectTask();
        Log.i(TAG, "CReated ins of ConnectTask");
        connectTask.execute("");
    }
}

private void ReConnect() {
    connectTask = null;

    if (HttpUtilities.checkInternetConnection()) {
        Log.i(TAG, "ABOUT TO RE-CONNECT");
        ConnectClicked();
    } else {
        Log.i(TAG, "No Interne Mesage");
        mMessage.setText(R.string.NO_INERNET);
    }
    return;
}

private void PrepareToStartToConnect() {
    monitorTimer = null;
    monitorConn = null;
    // Make all vars, objects to null   
}

// Start TimerTask & Timer object
private void StartTimer() {
    Log.i(TAG, "Into Start Timer");
    monitorConn = new MonitorConnection(this);   // new MonitorConnection(connectTask);
    monitorTimer = new Timer();
    monitorTimer.schedule(monitorConn, 0, 30000);
}


/**
 * ConnectTask  AsyncTask class that handles all activities to get connected to the server
 */
private class ConnectTask extends AsyncTask<String, Integer, Boolean> implements UINotifier {
    private ProgressDialog dialog = null;
    private UServer us = null;
    private VPNServer vs = null;
    private ConfigData cd = null;
    String serverHost = "", errorMsg = ""; 
    private int status = -1; // 0 Connected  1 = ReConnect  2 = Failed to Connect

    public ConnectTask() {
        dialog  = new ProgressDialog(StartUltimate.this);
        us  = servers.get(selectedRowIndex);
        vs = us.getVpnServer(selectedProtocol, selectedPort);
        serverHost = us.getServerHost();
    }

    private void disposeAll() {
        // Dispose all objs
    }

    @Override
    protected void onPostExecute(Boolean result) {
        super.onPostExecute(result);
        Log.i(TAG, "Into onPostExecute()");
        if (result == false)
            mMessage.setText(errorMsg);
        else
            mMessage.setText("");
        dialog.dismiss();
        // Clean up all variables of the object
        disposeAll();
        Log.i(TAG, "FINISHED onPostExecute()");
        // Go out of AsyncTask and have control to other method of Activity class
        StartTimer();
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        selectedServerHost = serverHost.substring(0, serverHost.indexOf('.'));
        dialog.setCancelable(false);
        dialog.setIcon(R.drawable.icon);
        dialog.setTitle("Progessing...");
        dialog.setMessage(String.valueOf(R.string.ui_activity_authenticating));
        dialog.show();
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        super.onProgressUpdate(values);
        // Set all updates to UI
        return;
    }

    @Override
    protected Boolean doInBackground(String... params) {
        Log.i(TAG, "Into doBackground...");
        ......
        Log.i(TAG, "Starting Connect.....");
        StartConnect();

        return true;
    }

    @Override
    public void notifyUI() {
        Log.i(TAG, "GOT MESSAGE FROM MonitorConnection");
        monitorTimer.cancel();
        Log.i(TAG, "Preparing to Start");
        PrepareToStartToConnect();
        publishProgress(4);
        status = 1;
        if (status == 1 || status == 2)
            ReConnect();
    }


    private void StartConnect() {
        // This is empty right now      
    }
}   // END OF ConnectTask class

StartTimer is called, and MonitorThread notifies Activity class and that calls ReConnect which inturn calls ConnectClicked. In ConnectClicked, connectTask = new ConnectTask(); is where I get this exception and the log :

04-15 17:09:07.501: INFO/Ultimate VPN:(364): Starting Connect.....
04-15 17:09:07.501: INFO/Ultimate VPN:(364): Into onPostExecute()
04-15 17:09:07.501: INFO/Ultimate VPN:(364): FINISHED onPostExecute()
04-15 17:09:07.501: INFO/Ultimate VPN:(364): Into Start Timer
04-15 17:09:07.542: INFO/MON CONN(364): Into StartMonitor
04-15 17:09:07.542: INFO/MON CONN(364): Into checkConnection
04-15 17:09:07.671: WARN/InputManagerService(69): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@4073b170
04-15 17:09:08.252: INFO/System.out(364): MonitorConnection : Notifing the GUI
04-15 17:09:08.262: INFO/Ultimate VPN:(364): GOT MESSAGE FROM MonitorConnection
04-15 17:09:08.262: INFO/Ultimate VPN:(364): Preparing to Start
04-15 17:09:18.322: INFO/Ultimate VPN:(364): ABOUT TO RE-CONNECT
04-15 17:09:18.322: INFO/Ultimate VPN:(364): Inside Connectclicked
04-15 17:09:18.322: INFO/Ultimate VPN:(364): isConnectionEligible = true
04-15 17:09:18.331: WARN/dalvikvm(364): threadid=11: thread exiting with uncaught exception (group=0x40015560)
04-15 17:09:18.351: ERROR/AndroidRuntime(364): FATAL EXCEPTION: Timer-0
04-15 17:09:18.351: ERROR/AndroidRuntime(364): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at android.os.Handler.<init>(Handler.java:121)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at android.app.Dialog.<init>(Dialog.java:101)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at android.app.AlertDialog.<init>(AlertDialog.java:63)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at android.app.ProgressDialog.<init>(ProgressDialog.java:80)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at android.app.ProgressDialog.<init>(ProgressDialog.java:76)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at orange.android.vpn.StartUltimate$ConnectTask.<init>(StartUltimate.java:386)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at orange.android.vpn.StartUltimate.ConnectClicked(StartUltimate.java:324)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at orange.android.vpn.StartUltimate.ReConnect(StartUltimate.java:340)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at orange.android.vpn.St开发者_运维知识库artUltimate.notifyUI(StartUltimate.java:316)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at orange.android.vpn.MonitorConnection.setConnected(MonitorConnection.java:43)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at orange.android.vpn.MonitorConnection.checkConnection(MonitorConnection.java:69)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at orange.android.vpn.MonitorConnection.StartMonitor(MonitorConnection.java:61)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at orange.android.vpn.MonitorConnection.run(MonitorConnection.java:52)
04-15 17:09:18.351: ERROR/AndroidRuntime(364):     at java.util.Timer$TimerImpl.run(Timer.java:284)
04-15 17:09:18.382: WARN/ActivityManager(69):   Force finishing activity orange.android.vpn/.StartUltimate

Any idea why I get this error ? How do I solve it ? I tried handling the UINotifier in ConnectTask class instead of Activity class. But the onPost is called immediately after StartConnect() , despite StartTimer was added to it and that thread was already running. Then also the doInBackground stops, so I managed it this way. But both the ways I get error. In other case I get ... Looper.... exception.

Any help is highly appreciated.

Thanks

I would get rid of the UINotifier (custom implementation) and look at using the out-of-the box Handler mechanism in Android to notify the UI.

See How to get XML using AsyncTask and Timer? for a similar implementation.

Also, see the Painless threading article here : http://developer.android.com/resources/articles/painless-threading.html for more information about threading (and Handlers)