java.lang.NullPointerException: Versuch, die virtuelle Methode 'java.io.File com.parse.ParsePlugins.getParseDir()' für eine Nullobjekt-Referenz aufzurufen

Question

Der Versuch, eine Klasse von Parse zu laden, jedoch stürzt die App so bald ich ab Starten Sie es! Hier ist der Code:

ListView listview; 
List<ParseObject> ob; 
ProgressDialog mProgressDialog; 
ArrayAdapter<String> adapter; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_big_board); 
    new RemoteDataTask().execute(); 

} 

private class RemoteDataTask extends AsyncTask<Void, Void, Void> { 
    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
     mProgressDialog = new ProgressDialog(BigBoard.this); 
     mProgressDialog.setTitle("Parse.com Simple ListView Tutorial"); 
     mProgressDialog.setMessage("Loading..."); 
     mProgressDialog.setIndeterminate(false); 
     mProgressDialog.show(); 
    } 

    @Override 
    protected Void doInBackground(Void... params) { 
     // Locate the class table named "Country" in Parse.com 
     ParseQuery<ParseObject> query = new ParseQuery<ParseObject>(
       "Country"); 
     query.orderByDescending("_created_at"); 
     try { 
      ob = query.find(); 
     } catch (ParseException e) { 
      Log.e("Error", e.getMessage()); 
      e.printStackTrace(); 
     } 
     return null; 
    } 

    @Override 
    protected void onPostExecute(Void result) { 
     // Locate the listview in listview_main.xml 
     listview = (ListView) findViewById(R.id.listview); 
     // Pass the results into an ArrayAdapter 
     adapter = new ArrayAdapter<String>(BigBoard.this, 
       R.layout.listview_item); 
     // Retrieve object "name" from Parse.com database 
     for (ParseObject country : ob) { 
      adapter.add((String) country.get("Name")); 
     } 
     // Binds the Adapter to the ListView 
     listview.setAdapter(adapter); 
     // Close the progressdialog 
     mProgressDialog.dismiss(); 
     // Capture button clicks on ListView items 
     listview.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView<?> parent, View view, 
            int position, long id) { 
       // Send single item click data to SingleItemView Class 
       Intent i = new Intent(BigBoard.this, 
         SingleItemView.class); 
       // Pass data "name" followed by the position 
       i.putExtra("name", ob.get(position).getString("name") 
         .toString()); 
       // Open SingleItemView.java Activity 
       startActivity(i); 
      } 
     }); 
    } 
} 

Und das ist, was ich in der logcat erhalten:

> 10-22 20:40:18.705 12588-12872/obx.com.futurister E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #3 
    Process: obx.com.futurister, PID: 12588 
    java.lang.RuntimeException: An error occurred while executing doInBackground() 
      at android.os.AsyncTask$3.done(AsyncTask.java:309) 
      at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354) 
      at java.util.concurrent.FutureTask.setException(FutureTask.java:223) 
      at java.util.concurrent.FutureTask.run(FutureTask.java:242) 
      at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234) 
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) 
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) 
      at java.lang.Thread.run(Thread.java:818) 
    Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.File com.parse.ParsePlugins.getParseDir()' on a null object reference 
      at com.parse.Parse.getParseDir(Parse.java:315) 
      at com.parse.ParseCorePlugins.getCurrentUserController(ParseCorePlugins.java:129) 
      at com.parse.ParseUser.getCurrentUserController(ParseUser.java:55) 
      at com.parse.ParseUser.getCurrentUserAsync(ParseUser.java:888) 
      at com.parse.ParseQuery.getUserAsync(ParseQuery.java:938) 
      at com.parse.ParseQuery$3.call(ParseQuery.java:1196) 
      at com.parse.ParseQuery$3.call(ParseQuery.java:1193) 
      at com.parse.ParseQuery.doWithRunningCheck(ParseQuery.java:1132) 
      at com.parse.ParseQuery.findAsync(ParseQuery.java:1193) 
      at com.parse.ParseQuery.findInBackground(ParseQuery.java:1161) 
      at com.parse.ParseQuery.find(ParseQuery.java:981) 
      at obx.com.futurister.BigBoard$RemoteDataTask.doInBackground(BigBoard.java:66) 
      at obx.com.futurister.BigBoard$RemoteDataTask.doInBackground(BigBoard.java:44) 
      at android.os.AsyncTask$2.call(AsyncTask.java:295) 
      at java.util.concurrent.FutureTask.run(FutureTask.java:237) 
            at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234) 
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) 
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) 
            at java.lang.Thread.run(Thread.java:818) 
10-22 20:40:18.857 12588-12619/obx.com.futurister E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xb3a1fb90 
10-22 20:40:18.955 12588-12619/obx.com.futurister E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xa96acbb0 
10-22 20:40:18.996 12588-12588/obx.com.futurister E/WindowManager﹕ android.view.WindowLeaked: Activity obx.com.futurister.BigBoard has leaked window com.android.internal.policy.PhoneWindow$DecorView{a0f50b2 V.E...... R......D 0,0-1026,538} that was originally added here 
      at android.view.ViewRootImpl.<init>(ViewRootImpl.java:368) 
      at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:299) 
      at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:85) 
      at android.app.Dialog.show(Dialog.java:319) 
      at obx.com.futurister.BigBoard$RemoteDataTask.onPreExecute(BigBoard.java:56) 
      at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:604) 
      at android.os.AsyncTask.execute(AsyncTask.java:551) 
      at obx.com.futurister.BigBoard.onCreate(BigBoard.java:40) 
      at android.app.Activity.performCreate(Activity.java:6237) 
      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) 
      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) 
      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
      at android.app.ActivityThread.-wrap11(ActivityThread.java) 
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
      at android.os.Handler.dispatchMessage(Handler.java:102) 
      at android.os.Looper.loop(Looper.java:148) 
      at android.app.ActivityThread.main(ActivityThread.java:5417) 
      at java.lang.reflect.Method.invoke(Native Method) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 

sein das Problem mit der doInBackground() Methode erraten? Fehle ich etwas? Bitte helfen, Danke

Answer 1

Basierend auf Ihrem Kommentar, ich vermute, Sie haben Parse nicht initialisiert. http://docs.parseplatform.org/android/guide/#local-datastore

public class App extends Application { 

    @Override 
    public void onCreate() { 
     super.onCreate(); 

     // Enable Local Datastore. 
     Parse.enableLocalDatastore(this); 

     // Register any ParseObject subclass. Must be done before calling Parse.initialize() 
     ParseObject.registerSubclass(YourClass.class); 

     Parse.initialize(this, "APPLICATION_ID", "CLIENT_KEY");  
    } 
} 

Stellen Sie sicher, Ihre App-Klasse das Manifest