BufferedRead運行時崩潰

遇到BufferedReader操作時，我的應用程序崩潰。我試圖在asyncTask類中實現代碼，因爲我讀過崩潰是由ui線程引起的，但沒有任何改變。BufferedRead運行時崩潰

public class URLConnectionReader extends AsyncTask<URL, Void, String> { 

    String result = null; 

    @Override 
    protected String doInBackground(URL... params) { 

     String result = null; 

     URL url = (params[0]); 

     try { 

      BufferedReader reader = new BufferedReader(
        new InputStreamReader(
          url.openStream() 
        ) 
      ); 

     }catch (IOException e){ 
      e.printStackTrace(); 
     } 

     return result; 

    } 
}

日誌

03-02 13:28:43.215 25186-25186/com.example.jsonreader E/AndroidRuntime﹕ FATAL EXCEPTION: main 
    Process: com.example.jsonreader, PID: 25186 
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.jsonreader/com.example.jsonreader.MainActivity}: android.os.NetworkOnMainThreadException 
      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298) 
      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
      at android.app.ActivityThread.access$800(ActivityThread.java:144) 
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
      at android.os.Handler.dispatchMessage(Handler.java:102) 
      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$MethodAndArgsCaller.run(ZygoteInit.java:899) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 
    Caused by: android.os.NetworkOnMainThreadException 
      at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1147) 
      at java.net.InetAddress.lookupHostByName(InetAddress.java:418) 
      at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252) 
      at java.net.InetAddress.getAllByName(InetAddress.java:215) 
      at com.android.okhttp.HostResolver$1.getAllByName(HostResolver.java:29) 
      at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:232) 
      at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:124) 
      at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:272) 
      at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:211) 
      at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:373) 
      at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:323) 
      at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:190) 
      at java.net.URL.openStream(URL.java:470) 
      at com.example.jsonreader.URLConnectionReader.doInBackground(URLConnectionReader.java:38) 
      at com.example.jsonreader.MainActivity.onCreate(MainActivity.java:27) 
      at android.app.Activity.performCreate(Activity.java:5933) 
      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105) 
      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251) 
      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
      at android.app.ActivityThread.access$800(ActivityThread.java:144) 
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
      at android.os.Handler.dispatchMessage(Handler.java:102) 
      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)

MainActivity代碼

public class MainActivity extends ActionBarActivity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState){ 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     try { 
      URL address = new URL("http://www.youth-stories.com/api/all.php"); 
      URLConnectionReader reader = new URLConnectionReader(); 
      String result = reader.doInBackground(address); 
      Toast.makeText(getApplicationContext(),result,Toast.LENGTH_LONG).show(); 
     }catch (IOException e){ 
      e.printStackTrace(); 
     }

來源

2015-03-02 Armando Alberti

你有一個異常堆棧跟蹤問題找回數據？ – pL4Gu33 2015-03-02 12:28:42

0錯誤和0警告 – 2015-03-02 12:30:57

也許不是，只是教我 – 2015-03-02 12:32:45

我解決了使用不用彷徨指令

String result = reader.execute(address).get();

來源

2015-03-02 13:37:56

但是你知道這個解決方案鎖定用戶界面，直到你得到結果 – 2015-03-02 13:52:15

BufferedRead運行時崩潰

回答

相關問題