Null-Zeiger-Ausnahme während ParseJSON

Question

Wenn ich versuche, den JSON zu analysieren, wird eine Nullzeigerausnahme ausgelöst. Auch wenn ich versuche, die Werte anzuzeigen, wird nichts angezeigt.

Code:

public class ParseJSON { 
    //public static String[] ids; 
    public static String[] names; 
    public static String[] message; 

    public static final String JSON_ARRAY = "users"; 
    // public static final String KEY_ID = "id"; 
    public static final String KEY_NAME = "username"; 
    public static final String KEY_EMAIL = "message"; 

    private JSONArray users = null; 

    private String json; 

    public ParseJSON(String json){ 
     this.json = json; 
    } 

    protected void parseJSON(){ 
     JSONObject jsonObject=null; 
     try { 
      jsonObject = new JSONObject(json); 
      users = jsonObject.getJSONArray(JSON_ARRAY); 

      //final String TAG = events.class.getSimpleName(); 
      //Log.d(TAG, "username value: \n" + KEY_NAME); 


      for(int i=0;i<users.length();i++){ 
       JSONObject jo = users.getJSONObject(i); 
       // ids[i] = jo.getString(KEY_ID); 
       names[i] = jo.getString(KEY_NAME); 
       message[i] = jo.getString(KEY_EMAIL); 
      } 
     } catch (JSONException e) { 
      e.printStackTrace(); 
     } 
    } 
} 

, aber wenn ich die den Parse-Wert anzuzeigen versuchen, ich kann es in einer anderen Seite bin Anzeige, da, wenn ich versuche, kann Werte LOG.d mit angezeigt werden, es zeigt Werte.

list_view.java

private void sendRequest(){ 


     StringRequest stringRequest = new StringRequest(JSON_URL, 
       new Response.Listener<String>() { 



        @Override 
        public void onResponse(String response) { 
         showJSON(response); 
        } 
       }, 


       new Response.ErrorListener() { 
        @Override 
        public void onErrorResponse(VolleyError error) { 
         Toast.makeText(list_view.this,error.getMessage(),Toast.LENGTH_LONG).show(); 
        } 
       }); 

     RequestQueue requestQueue = Volley.newRequestQueue(this); 
     requestQueue.add(stringRequest); 
    } 




    private void showJSON(String json){ 

     final String TAG = events.class.getSimpleName(); 
     Log.d(TAG, "showJSON: \n" + json); 

     ParseJSON pj = new ParseJSON(json); 
     pj.parseJSON(); 
     CustomList cl = new CustomList(this,ParseJSON.names,ParseJSON.message); 
     listView.setAdapter(cl); 
    } 

    @Override 
    public void onClick(View v) { 
     sendRequest(); 
    } 
} 

Hier ist der Fehler;

04-24 21:49:39.449 15992-15992/? D/events: showJSON: 
              {"users":[{"username":"varun","message":"hello word, my first message "},{"username":"varun","message":"hello word, my first message "},{"username":"rahul","message":"hello world"},{"username":"rahul","message":"world: its cool"},{"username":"rahul","message":"awesom"},{"username":"rahul","message":"ranom"},{"username":"rahul","message":"randimagain"},{"username":"rahi","message":"is it me again"},{"username":"rahull","message":"hi rahul"},{"username":"rahul","message":"world, am bacj"},{"username":"rahul","message":"hello parents"},{"username":"","message":""},{"username":"","message":""},{"username":"","message":""},{"username":"","message":""},{"username":"","message":""},{"username":"varun","message":"google world"},{"username":"rahul","message":"ollaaa"},{"username":"rahul","message":"ollaaa"},{"username":"rahul","message":"where are others"},{"username":"rahul","message":"where are others"},{"username":"varun","message":"oil spil"},{"username":"varun","message":"phone"},{"username":"vatun","message":"tttt"},{"username":"varun","message":"poiuytrew"},{"username":"rahui","message":"yregh"},{"username":"varun","message":"huiokgddfv"},{"username":"rahi","message":"poiutghklnbfd"},{"username":"rahui","message":"qwerty"},{"username":"varub","message":"hi eat pineapple"},{"username":"varun","message":"hi prabh"},{"username":"rahul","message":"hi world"},{"username":"ggjdjjf","message":"yhvdhhj"},{"username":"tgggg","message":"hhhh"},{"username":"rahul","message":"lqvrl"},{"username":"hhhh","message":"ghh"},{"username":"tff","message":"gg"},{"username":"hfdhn","message":"hnnnme"},{"username":"popo","message":"plpl"},{"username":"rahulpop","message":"op music"},{"username":"rtrt","message":"tyty"},{"username":"hlpo","message":"opop"},{"username":"hlpoghhj","message":"opop"},{"username":"tt","message":"hhh"},{"username":"ttere","message":"hhh"},{"username":"gytgjyg","message":"lajdhd"},{"username":"topo","message":"ptpt"},{"username":"jgj","message":"rtr"},{"username":"ry","message":"yr"},{"username":"ry","message":"yr"},{"username":"y","message":"q"},{"username":"u","message":"t"},{"username":"tt","message":"pp"},{"username":"q","message":"z"},{"username":"w","message":"v"},{"username":"e","message":"e."},{"username":"ui","message":"ui"},{"username":"yi","message":"yi"},{"username":"gg","message":"g"},{"username":"e","message":"e"},{"username":"h","message":"hh"},{"username":"j","message":"j"},{"username":"j","message":"k"},{"username":"v","message":"v"}]} 
04-24 21:49:39.459 15992-15992/? D/AndroidRuntime: Shutting down VM 
04-24 21:49:39.459 15992-15992/? W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x40c1ea68) 
04-24 21:49:39.529 15992-15992/? E/AndroidRuntime: FATAL EXCEPTION: main 
                java.lang.NullPointerException 
                 at com.weavearound.schools.weavearound.ParseJSON.parseJSON(ParseJSON.java:43) 
                 at com.weavearound.schools.weavearound.list_view.showJSON(list_view.java:76) 
                 at com.weavearound.schools.weavearound.list_view.access$000(list_view.java:22) 
                 at com.weavearound.schools.weavearound.list_view$1.onResponse(list_view.java:51) 
                 at com.weavearound.schools.weavearound.list_view$1.onResponse(list_view.java:45) 
                 at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:67) 
                 at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30) 
                 at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99) 
                 at android.os.Handler.handleCallback(Handler.java:605) 
                 at android.os.Handler.dispatchMessage(Handler.java:92) 
                 at android.os.Looper.loop(Looper.java:137) 
                 at android.app.ActivityThread.main(ActivityThread.java:4517) 
                 at java.lang.reflect.Method.invokeNative(Native Method) 
                 at java.lang.reflect.Method.invoke(Method.java:511) 
                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993) 
                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760) 
                 at dalvik.system.NativeStart.main(Native Method) 
04-24 21:49:39.559 403-420/? E/android.os.Debug: !@Dumpstate > dumpstate -k -t -n -z -d -o /data/log/dumpstate_app_error 

Answer 1

Ihr Problem ist, dass das String-Array nicht initialisiert wird.

names = new String[100]; 
messages = new String[100];