Android - Why calling this function directly instead of onClick causes a NullPointerException?

Question

I am trying to integrate the Sinch Android SDK in my project and I wanted to remove the Login button, i.e. such that the Activity switches to the next activity without the user having to click the Login button. For this, I removed the code for setOnClickListener for the mLoginButton and instead, directly called the loginClicked() function, which was previously being called from the onClick() method.
But this causes NullPointerException: Attempt to invoke virtual method 'boolean com.example.yankee.cw.SinchService$SinchServiceInterface.isStarted()' on a null object reference.
These are the only changes I made to the code:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);

        mLoginName = (EditText) findViewById(R.id.loginName);

        mLoginButton = (Button) findViewById(R.id.loginButton);
        mLoginButton.setEnabled(false);
//        mLoginButton.setOnClickListener(new OnClickListener() {
//            @Override
//            public void onClick(View v) {
//                loginClicked();
//            }
//        });
        loginClicked();
    }

And earlier it was like this:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);

        mLoginName = (EditText) findViewById(R.id.loginName);

        mLoginButton = (Button) findViewById(R.id.loginButton);
        mLoginButton.setEnabled(false);
        mLoginButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                loginClicked();
            }
        });
    }

Why doesn't this work and gives the NullPointerException instead ?

Edit: LoginActivity.java

It is already provided, the rest of the code is same as before. Sorry I didn't link it. I have added the link now. — Yankee, Nov 02 '16 at 07:33
@Yankee please provide the loginClicked() method for the understanding the problem. — LoveAndroid, Nov 02 '16 at 07:36
Problem is in base activity. Make sure you have same base activity as provided in the sample. Also make you sure you provide username. I think it won't work without user name — Zeeshan Shabbir, Nov 02 '16 at 07:40
@ZeeshanShabbir , Yes, everything else is the same. I have also provided the usernames. — Yankee, Nov 02 '16 at 07:41
If you dont want a login I would not load a activity and close it, you should rather move the implementation to i.e on app started and use what ever username you have stored. As Ishan pointed out it works, but the implementation gets very hacky — cjensen, Nov 02 '16 at 16:19

Ishan · Accepted Answer · 2016-11-02T07:49:21.523

3

getSinchServiceInterface() method is returning null that is why you are getting null pointer exception.

Earlier loginCliked() method was getting called after button was enabled in onServiceConnected method.

try calling loginClicked() method in onServiceConnected() method or use some delay.

edited Nov 02 '16 at 07:49

answered Nov 02 '16 at 07:42

Ishan

1,125
10
23

Wow, bro. I've been crying over this problem since a week. And this just worked. Thanks a lot. – Yankee Nov 02 '16 at 07:47
your welcome :) – Ishan Nov 02 '16 at 07:48
Would you please mind explaining it to me briefly why `loginClicked()` needed to be placed in the `onServiceConnected()` ? – Yankee Nov 02 '16 at 07:48
1

getSinchServiceInterface() is not getting initialized till onServiceConnected() method is called and that is why it is returning null. – Ishan Nov 02 '16 at 07:50

score 2 · Answer 2 · edited Apr 24 '17 at 13:05

2

My solution :

final Handler handler = new Handler();
    handler.postDelayed(new Runnable() {
    @Override
    public void run() {
       loginClicked();
    }
}, 4000);

edited Apr 24 '17 at 13:05

Mukesh Ram

5,814
4
15
34

answered Nov 28 '16 at 08:22

Dekel Laifer

29
2

1

Welcome to SO! Please check the formatting of your source code - see http://meta.stackexchange.com/questions/22186/how-do-i-format-my-code-blocks – Michael Lihs Nov 28 '16 at 08:29
@Dekel well done, u saved my day. – Däñish Shärmà Apr 24 '17 at 12:51

Android - Why calling this function directly instead of onClick causes a NullPointerException?

2 Answers2