Login using facebook sdk gives error on onActivityResult

Question

I am getting error while using facebook sdk. it gives me an error on OnActivtyResult method.

Please review my code given below.

This is the LogCat result:

07-05 22:33:51.762 24690-24690/uni.ek.com.re_think E/AndroidRuntime: FATAL EXCEPTION: main
                                                                 java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=64206, result=-1, data=Intent { (has extras) }} to activity {uni.ek.com.re_think/uni.ek.com.re_think.MainActivity}: java.lang.NullPointerException
                                                                     at android.app.ActivityThread.deliverResults(ActivityThread.java:3462)
                                                                     at android.app.ActivityThread.handleSendResult(ActivityThread.java:3505)
                                                                     at android.app.ActivityThread.access$1100(ActivityThread.java:150)
                                                                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1346)
                                                                     at android.os.Handler.dispatchMessage(Handler.java:99)
                                                                     at android.os.Looper.loop(Looper.java:213)
                                                                     at android.app.ActivityThread.main(ActivityThread.java:5225)
                                                                     at java.lang.reflect.Method.invokeNative(Native Method)
                                                                     at java.lang.reflect.Method.invoke(Method.java:525)
                                                                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741)
                                                                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
                                                                     at dalvik.system.NativeStart.main(Native Method)
                                                                  Caused by: java.lang.NullPointerException
                                                                     at uni.ek.com.re_think.MainActivity.onActivityResult(MainActivity.java:134)
                                                                     at android.app.Activity.dispatchActivityResult(Activity.java:5322)
                                                                     at android.app.ActivityThread.deliverResults(ActivityThread.java:3458)
                                                                     at android.app.ActivityThread.handleSendResult(ActivityThread.java:3505) 
                                                                     at android.app.ActivityThread.access$1100(ActivityThread.java:150) 
                                                                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1346) 
                                                                     at android.os.Handler.dispatchMessage(Handler.java:99) 
                                                                     at android.os.Looper.loop(Looper.java:213) 
                                                                     at android.app.ActivityThread.main(ActivityThread.java:5225) 
                                                                     at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                     at java.lang.reflect.Method.invoke(Method.java:525) 
                                                                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741) 
                                                                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557) 
                                                                     at dalvik.system.NativeStart.main(Native Method) 

This is the MainActivity:

package uni.ek.com.re_think;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.FacebookSdk;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;

public class MainActivity extends AppCompatActivity {

EditText name,pass;
Button login;
LoginButton fb_login;
String name1,pass1;
int count,counter;
CallbackManager callbackManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    FacebookSdk.sdkInitialize(getApplicationContext());
    CallbackManager callbackManager = CallbackManager.Factory.create();

    setContentView(R.layout.activity_main);






    fb_login= (LoginButton)findViewById(R.id.btnl_fblogin);
    //////////////////
    fb_login.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
        @Override
        public void onSuccess(LoginResult loginResult) {

            Toast.makeText(getApplicationContext(),"success",Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onCancel() {

        }

        @Override
        public void onError(FacebookException error) {

        }
    });


}




@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    callbackManager.onActivityResult(requestCode, resultCode, data);


}

}

Mainfest.xml

<?xml version="1.0" encoding="utf-8"?>

<uses-permission android:name="android.permission.INTERNET"/>

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

    <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/app_id"/>

    <activity android:name="com.facebook.FacebookActivity"
        android:configChanges=
            "keyboard|keyboardHidden|screenLayout|screenSize|orientation"
        android:theme="@android:style/Theme.Translucent.NoTitleBar"
        android:label="@string/app_name" />
    <activity android:name=".MainActivity" android:screenOrientation="portrait">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

</application>

Please solve the issue

Answer 1

callbackManager is always null as it is only a local var. Change your onCreate to fill in the class field /member like so:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    FacebookSdk.sdkInitialize(getApplicationContext());
    callbackManager = CallbackManager.Factory.create();
    //..  the rest of your onCreate