SharedPreference, Facebook Integration, NullPointerException

Question

Ich versuche Facebook Integration mit meiner App. Ich habe meine Login-Taste in einem Fragment, das in einer Aktivität ist.

wenn ich zurück zu meiner Haupttätigkeit gehe und zu meiner Facebook-Aktivität zurückkomme. Ich bekomme Nullzeiger Ausnahme. Ich verwende Shared preference, um die Daten des Benutzers zu behalten und auf die spezifischen textViews zu setzen.

Fragment mit Facebook login (Ich entfernte die Einfuhren aus Gründen der Frage)

public class Profilee extends Fragment { 
    static String email1, birthday1, gender1; 
    ImageView imageView; 
    static int itis = 1; 
    TextView texty; 
    LoginButton button; 
    LinearLayout userinput; 
    private CallbackManager callbackManager; 
    private TextView textView; 
    SharedPreferences pref; 
    private TextView email, birthday, gende; 
    private AccessTokenTracker accessTokenTracker; 
    private ProfileTracker profileTracker; 
    static String mail,gender,name; 


    private FacebookCallback<LoginResult> callback = new FacebookCallback<LoginResult>() { 
     @Override 
     public void onSuccess(LoginResult loginResult) { 
      AccessToken accessToken = loginResult.getAccessToken(); 
      Profile profile = Profile.getCurrentProfile(); 
      GraphRequest graphrequest = GraphRequest.newMeRequest(loginResult.getAccessToken(), 
        new GraphRequest.GraphJSONObjectCallback() { 

         @Override 
         public void onCompleted(JSONObject object, GraphResponse response) { 
          JSONObject jsonObject = response.getJSONObject(); 
          if (jsonObject != null) { 
           try { 
            email1 = jsonObject.getString("email"); 
            gender1 = jsonObject.getString("gender"); 
            birthday1 = jsonObject.getString("birthday"); 
           } catch (JSONException e) { 
            e.printStackTrace(); 
           } 
          } 
         } 
        }); 
      Bundle parameters = new Bundle(); 
      parameters.putString("fields", "email, gender, birthday"); 
      graphrequest.setParameters(parameters); 
      graphrequest.executeAsync(); 
      AppEventsLogger.activateApp(getContext()); 
     } 

     @Override 
     public void onCancel() { 

     } 

     @Override 
     public void onError(FacebookException e) { 

     } 
    }; 

    public Profilee() { 
     // Required empty public constructor 
    } 

    public boolean m; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     FacebookSdk.sdkInitialize(getActivity().getApplicationContext()); 
     callbackManager = CallbackManager.Factory.create(); 
     Toast.makeText(getContext(), "Create", Toast.LENGTH_SHORT).show(); 



      pref = getContext().getSharedPreferences("hello", getContext().MODE_PRIVATE); 
      pref.getString("name", "asdfgh"); 
      pref.getString("email", "qwerty"); 
      pref.getString("gender", "zxcvb"); 



      accessTokenTracker = new AccessTokenTracker() { 
       @Override 
       protected void onCurrentAccessTokenChanged(AccessToken oldToken, AccessToken newToken) { 
       } 
      }; 



     profileTracker = new ProfileTracker() { 
      @Override 
      protected void onCurrentProfileChanged(Profile oldProfile, Profile newProfile) { 
      } 
     }; 

     accessTokenTracker.startTracking(); 
     profileTracker.startTracking(); 

     onResume(); 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     View v = inflater.inflate(R.layout.fragment_profilee, container, false); 
     button = (LoginButton) v.findViewById(R.id.login_button); 
     TextView button12 = (TextView) v.findViewById(R.id.edit); 
     button12.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent i = new Intent(getContext(), PrifileEdit.class); 
       i.putExtra("st", email1); 
       startActivity(i); 
      } 
     }); 
     texty = (TextView) v.findViewById(R.id.emo); 
     imageView = (ImageView) v.findViewById(R.id.asd); 
     userinput = (LinearLayout) v.findViewById(R.id.userdetail); 
     int unicode = 0x1F60E; 
     String emoji = getEmijoByUnicode(unicode); 
     String text = "We will never post on your wall without permission "; 
     texty.setText(text + emoji); 

     Toast.makeText(getContext(), "CreateView", Toast.LENGTH_SHORT).show(); 
     return v; 
    } 


    public String getEmijoByUnicode(int unicode) { 
     return new String(Character.toChars(unicode)); 
    } 


    @Override 
    public void onViewCreated(View view, Bundle savedInstanceState) { 
     super.onViewCreated(view, savedInstanceState); 
     LoginButton loginButton = (LoginButton) view.findViewById(R.id.login_button); 
     textView = (TextView) view.findViewById(R.id.textView); 
     email = (TextView) view.findViewById(R.id.emailid); 
     gende = (TextView) view.findViewById(R.id.gender); 
     birthday = (TextView) view.findViewById(R.id.birth); 
     loginButton.setReadPermissions("email"); 
     loginButton.setFragment(this); 
     loginButton.registerCallback(callbackManager, callback); 
     Toast.makeText(getContext(), "ViewCreate", Toast.LENGTH_SHORT).show(); 


    } 

    @Override 
    public void onActivityResult(int requestCode, int resultCode, Intent data) { 
     super.onActivityResult(requestCode, resultCode, data); 
     callbackManager.onActivityResult(requestCode, resultCode, data); 
     new Handler().postDelayed(new Runnable() { 
      @Override 
      public void run() { 
       onResume(); 
      } 
     }, 2000); 
    } 

    public void displayMessage(final Profile profile) { 

     pref = getContext().getSharedPreferences("hello", getContext().MODE_PRIVATE); 
     SharedPreferences.Editor editor = pref.edit(); 
     m=pref.getBoolean("key",true); 


      if(m==true) { 
       if (profile != null) { 
        textView.setText(profile.getName()); 
        email.setText(email1); 
        gende.setText(gender1); 
        birthday.setText(birthday1); 
        button.setVisibility(View.GONE); 
        texty.setVisibility(View.GONE); 
        userinput.setVisibility(View.VISIBLE); 
        pref = getContext().getSharedPreferences("hello", getContext().MODE_PRIVATE); 


        editor.putString("email",email1); 
        editor.putString("name",profile.getName()); 
        editor.putString("gender",gender1); 
        editor.putBoolean("key",false); 
        editor.commit(); 
       } 
      } else if(m==false){ 
       mail=pref.getString("email","lol1"); 
       gender=pref.getString("gender","lol2"); 
       name=pref.getString("name","lol3"); 
       textView.setText(name); 
       email.setText(mail); 
       gende.setText(gender); 


      } 

    } 

    @Override 
    public void onStart() { 
     super.onStart(); 
     Toast.makeText(getContext(), "Start", Toast.LENGTH_SHORT).show(); 
    } 


    @Override 
    public void onStop() { 
     super.onStop(); 
     accessTokenTracker.stopTracking(); 
     profileTracker.stopTracking(); 
    } 

    @Override 
    public void onResume() { 
     super.onResume(); 
     Profile profile = Profile.getCurrentProfile(); 
     displayMessage(profile); 
     AppEventsLogger.activateApp(getContext()); 
    } 
} 

Acitivty mit dem obigen Fragment

public class Profile extends AppCompatActivity { 
    private ViewPagerAdapter mSectionsPagerAdapter; 
    private ViewPager mViewPager; 
    TextView textView, textView2; 
    SharedPreferences sp; 
    private static String totalurl = "random.com/l.php"; 
    public static final String MyPREFERENCES = "User" ; 
    public static final String UserID = "UserIDKey"; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_profile); 
     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 
     ActionBar actionBar = getSupportActionBar(); 
     if (actionBar != null) { 
      actionBar.setHomeButtonEnabled(true); 
      actionBar.setDisplayHomeAsUpEnabled(true); 
     } 
     mSectionsPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager()); 

     mViewPager = (ViewPager) findViewById(R.id.container); 
     mViewPager.setAdapter(mSectionsPagerAdapter); 
     setupViewPager(mViewPager); 
     TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs); 
     tabLayout.setupWithViewPager(mViewPager); 
     textView = (TextView) findViewById(R.id.redeem); 

     SharedPreferences sp = getSharedPreferences("User", Context.MODE_PRIVATE); 
     totalearn(); 
     textView.setText("₹ " + sp.getString("A_EARN", "")); 
     textView2.setText("₹ "+sp.getString("T_EARN","")); 

    } 


    private void setupViewPager(ViewPager viewPager) { 
     ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager()); 
     adapter.addFragment(new Profilee(), "PROFILE"); 
     adapter.addFragment(new Redeem(), "REDEEM"); 
     //adapter.addFragment(new History(), "HISTORY"); 
     viewPager.setAdapter(adapter); 
    } 


    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 


     switch (item.getItemId()) { 
      case android.R.id.home: 
       finish(); 
       return true; 
      default: 
       return super.onOptionsItemSelected(item); 
     } 

    } 


    public class ViewPagerAdapter extends FragmentPagerAdapter { 
     private final List<Fragment> mFragmentList = new ArrayList<>(); 
     private final List<String> mFragmentTitleList = new ArrayList<>(); 

     public ViewPagerAdapter(FragmentManager fm) { 
      super(fm); 
     } 

     @Override 
     public Fragment getItem(int position) { 
      return mFragmentList.get(position); 
     } 


     public void addFragment(Fragment fragment, String title) { 
      mFragmentList.add(fragment); 
      mFragmentTitleList.add(title); 
     } 


     @Override 
     public int getCount() { 
      return mFragmentList.size(); 
     } 

     @Override 
     public CharSequence getPageTitle(int position) { 
      return mFragmentTitleList.get(position); 
     } 
    } 
    public void redeem(View v){ 
     Intent internet = new Intent(); 
     internet.setAction(Intent.ACTION_VIEW); 
     internet.addCategory(Intent.CATEGORY_BROWSABLE); 
     internet.setData("my")); 
     startActivity(internet); 
    } 
} 

Logcat

FATAL EXCEPTION: mainProcess: earn.free.cashback.snapcash, PID: 3959 
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference 
at earn.free.cashback.snapcash.fragments.Profilee.displayMessage(Profilee.java:241) 
at earn.free.cashback.snapcash.fragments.Profilee.onResume(Profilee.java:268) 
at earn.free.cashback.snapcash.fragments.Profilee.onCreate(Profilee.java:149) 
at android.support.v4.app.Fragment.performCreate(Fragment.java:1951) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1029) 
at android.support.v4.app.FragmentManagerImpl.performPendingDeferredStart(FragmentManager.java:926) 
at android.support.v4.app.Fragment.setUserVisibleHint(Fragment.java:876) 
at android.support.v4.app.FragmentPagerAdapter.setPrimaryItem(FragmentPagerAdapter.java:130) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:1175) 
at android.support.v4.view.ViewPager.populate(ViewPager.java:1025) 
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1545) 
at android.view.View.measure(View.java:17430) 
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463) 
at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:664) 
at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:731) 
at android.view.View.measure(View.java:17430) 
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463) 
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430) 
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135) 
at android.view.View.measure(View.java:17430) 
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463) 
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436) 
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722) 
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613) 
at android.view.View.measure(View.java:17430) 
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463) 
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430) 
at android.view.View.measure(View.java:17430) 
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463) 
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436) 
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722) 
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613) 
at android.view.View.measure(View.java:17430) 
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463) 
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430) 
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2560) 
at android.view.View.measure(View.java:17430) 
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2001) 
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1166) 
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1372) 
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1054) 
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5779) 
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767) 
at android.view.Choreographer.doCallbacks(Choreographer.java:580) 
at android.view.Choreographer.doFrame(Choreographer.java:550) 
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753) 
at android.os.Handler.handleCallback(Handler.java:739) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5221) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 

Answer 1

Bevor Sie setText setzen, stellen Sie sicher, dass Sie keinen NULL-Wert übergeben. Ich denke das Problem liegt hier, die übergebenen Werte müssen null sein, daher NullPointerException.

   email.setText(email1); 
       gende.setText(gender1); 
       birthday.setText(birthday1); 

Answer 2

Ihre onResume() ändern wie folgt aussehen:

public void onResume() { 
     super.onResume(); 
     textView = (TextView) getView().findViewById(R.id.textView); 
     email = (TextView) getView().findViewById(R.id.emailid); 
     gende = (TextView) getView().findViewById(R.id.gender); 
     birthday = (TextView) getView().findViewById(R.id.birth); 
     Profile profile = Profile.getCurrentProfile(); 
     displayMessage(profile); 
     AppEventsLogger.activateApp(getContext()); 
    }