onProgressUpdate에 대한 NullPointerException

Question

정확히 Null이 무슨 말을하는지 이해하려고했지만 올바른 값을 가진 배열을 넣었습니다. 그래서 누군가가 나에게 해결책을 줄 수 있다면 좋을 것입니다.

로그 캣 :

02-29 23:03:52.078: D/Surface(4619): Surface is full screen 
02-29 23:03:52.088: D/AndroidRuntime(4619): Shutting down VM 
02-29 23:03:52.088: W/dalvikvm(4619): threadid=1: thread exiting with uncaught exception (group=0x4001d560) 
02-29 23:03:52.088: E/AndroidRuntime(4619): FATAL EXCEPTION: main 
02-29 23:03:52.088: E/AndroidRuntime(4619): java.lang.NullPointerException 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at com.ratetheplate.application.Reviews$Read.onProgressUpdate(Reviews.java:115) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at com.ratetheplate.application.Reviews$Read.onProgressUpdate(Reviews.java:1) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:432) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at android.os.Handler.dispatchMessage(Handler.java:99) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at android.os.Looper.loop(Looper.java:130) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at android.app.ActivityThread.main(ActivityThread.java:3835) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at java.lang.reflect.Method.invokeNative(Native Method) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at java.lang.reflect.Method.invoke(Method.java:507) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:883) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:641) 
02-29 23:03:52.088: E/AndroidRuntime(4619):  at dalvik.system.NativeStart.main(Native Method) 

자바 :

package com.ratetheplate.application; 

import java.io.IOException; 

import org.apache.http.HttpEntity; 
import org.apache.http.HttpResponse; 
import org.apache.http.client.ClientProtocolException; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.methods.HttpGet; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.apache.http.util.EntityUtils; 
import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 
import android.app.Activity; 
import android.app.ProgressDialog; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.view.Window; 
import android.view.WindowManager; 
import android.widget.TextView; 
import android.widget.Toast; 

public class Reviews extends Activity { 

TextView rssStuff; 
HttpClient client; 
JSONObject json; 
final static String URL = "http://api.tumblr.com/v2/blog/ratetheplate.tumblr.com/posts.json?api_key=*********************"; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 

    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
      WindowManager.LayoutParams.FLAG_FULLSCREEN); 

    setContentView(R.layout.reviews); 
    rssStuff = (TextView) findViewById(R.id.rss); 
    client = new DefaultHttpClient(); 
    new Read().execute("posts"); 

} 

public JSONObject lastPost(String review) throws ClientProtocolException, 
     IOException, JSONException { 

    HttpGet get = new HttpGet(URL.toString()); 
    HttpResponse r = client.execute(get); 
    int status = r.getStatusLine().getStatusCode(); 
    if (status == 200) { 
     HttpEntity e = r.getEntity(); 
     String data = EntityUtils.toString(e); 
     JSONArray timeline = new JSONArray(data); 
     JSONObject last = timeline.getJSONObject(0); 
     return last; 
    } else { 
     Toast.makeText(Reviews.this, "Error", Toast.LENGTH_SHORT); 
     return null; 
    } 
} 

public class Read extends AsyncTask<String, Integer, String> { 

    String title, msg; 
    ProgressDialog dialog; 

    protected void onPreExectute() { 
     title = "Loading"; 
     msg = "Loading Reviews..."; 
     dialog = new ProgressDialog(Reviews.this); 
     dialog.setTitle(title); 
     dialog.setMessage(msg); 
     dialog.setIndeterminate(false); 
     dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL); 
     dialog.setProgress(0); 
     dialog.setMax(100); 
     dialog.show(); 
     super.onPreExecute(); 
    } 

    @Override 
    protected String doInBackground(String... params) { 
     // TODO Auto-generated method stub 
     for (int i = 0; i < 20; i++) { 
      publishProgress(5); 
      try { 
       Thread.sleep(88); 
      } catch (InterruptedException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
     } 
     dialog.dismiss(); 
     try { 
      json = lastPost("posts"); 
      return json.getString(params[0]); 
     } catch (ClientProtocolException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } catch (JSONException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
     return null; 
    } 

    protected void onProgressUpdate(Integer... progress) { 
     dialog.incrementProgressBy(progress[0]); 
     setProgress(progress[0]); 
    } 

    @Override 
    protected void onPostExecute(String result) { 
     // TODO Auto-generated method stub 
     rssStuff.setText(result); 
    } 
} 
} 

Answer 1

난 당신이 프로젝트 확인하고 onPreExecute 전에 초기화를 변경 : 그것은 나를 위해 일한

ProgressDialog dialog = new ProgressDialog(TestProjectActivity.this); 

.

Answer 2

어쩌면 ProgressDialog를 AsyncTask 내부가 아닌 Main Activity 안에 두어야합니다. 그런 다음 AsyncTask 클래스 내에서 초기화하십시오. 나는 이것을 가지고 일하고있다. 희망 사항이 적용됩니다.

Answer 3

AsyncTask의 onPreExecute() 메서드를 재정의하지 않았습니다. 당신은 방법 onPreExectute()를 만드는

이있는 당신은 dialog의 intializing을 할 수 있지만 그 방법은 명시 적으로 호출되지하지도 않고 결과 dialog로서 AsyncTask

여전히 null 인에 의해 당신은 publishProgress

변경을 수행 할 때 onPreExectute()에서 onPreExecute() 사이의 맞춤법과 그 위에 @override을 추가하십시오.