Application crashing when trying to teardown connection in android P2P

Question

I am trying to implement the google's sample for wifidirect connection. Everyhing works ok but on the option menu if I click on disconnect the app crashes with 'nullpointer exception'. The error is shown on the line 'mconnecion.teardown()';

@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
    case android.R.id.home:   // using app icon for navigation up or home:
        Log.d(TAG, "home clicked.");
        // startActivity(new Intent(home.class, Intent.FLAG_ACTIVITY_CLEAR_TOP));
        return true;

    case R.id.atn_direct_enable:
        startActivity(new Intent(Settings.ACTION_WIRELESS_SETTINGS));
        return true;
    case R.id.atn_direct_discover:

        listFragment.onInitiateDiscovery();
        Log.d(TAG, "onOptionsItemSelected : start discoverying ");
        discoverPeers();

        return true;

    case R.id.disconnect:
        Log.d(TAG, "onOptionsItemSelected : disconnect all connections and stop server ");
        mConnection.tearDown();
        mConnection=null;
        return true;

    default:
        return super.onOptionsItemSelected(item);
}
}

'mconnection' is a class and 'teardown()' method is like following

public void tearDown() {
mChatServer.tearDown();
mChatClient.tearDown();
isReady = false;
mContext = null;
}

How can i solve this problem?

Answer 1

Its showing null pointer exception because the object is null there. check if the object is null and the problem should not exist.

if (mConnection!=null)
    mConnection.tearDown();
    mConnection=null;
    return true;

This should solve your problem i hope