Android：無法啓動活動ComponentInfo：java.lang.NullPointerException

Question

當我運行我的Android應用程序時，出現錯誤「Unable to start activity ComponentInfo」錯誤。

這是錯誤似乎正在發生的類。

public class GalleryZoom extends Activity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     requestWindowFeature(Window.FEATURE_NO_TITLE); 
     getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN); 
     setContentView(R.layout.gallery_zoom); 

     ImageView image = (ImageView) findViewById(R.id.imageZoom); 
     String selection = getIntent().getExtras().getString("image"); 
     Toast.makeText(this, selection, Toast.LENGTH_LONG).show(); 


     BitmapFactory.Options bmpOptions; 
     bmpOptions = new BitmapFactory.Options(); 
     bmpOptions.inSampleSize = 1; 
     Bitmap bmp = LoadImage(getIntent().getExtras().getString("image"), bmpOptions); 
     image.setImageBitmap(bmp); 

    } 

    private Bitmap LoadImage(String URL, BitmapFactory.Options options) { 
     Bitmap bitmap = null; 
     InputStream in = null; 
     try { 
      in = OpenHttpConnection(URL); 
      bitmap = BitmapFactory.decodeStream(in, null, options); 
      in.close(); 
     } catch (IOException e1) { 
     } 
     return bitmap; 
    } 

    private InputStream OpenHttpConnection(String strURL) throws IOException { 
     InputStream inputStream = null; 
     URL url = new URL(strURL); 
     URLConnection conn = url.openConnection(); 

     try { 
      HttpURLConnection httpConn = (HttpURLConnection) conn; 
      httpConn.setRequestMethod("GET"); 
      httpConn.connect(); 

      if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) { 
       inputStream = httpConn.getInputStream(); 
      } 
     } catch (Exception ex) { 
     } 
     return inputStream; 
    } 

} 

以下是我的LogCat錯誤消息。

07-20 00:15:12.779: D/AndroidRuntime(802): Shutting down VM 
07-20 00:15:12.779: W/dalvikvm(802): threadid=1: thread exiting with uncaught exception (group=0x40a13300) 
07-20 00:15:12.789: E/AndroidRuntime(802): FATAL EXCEPTION: main 
07-20 00:15:12.789: E/AndroidRuntime(802): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.example.mobile.application/com.example.example.mobile.application.gallery.GalleryZoom}: java.lang.NullPointerException 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059) 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.app.ActivityThread.access$600(ActivityThread.java:130) 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.os.Handler.dispatchMessage(Handler.java:99) 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.os.Looper.loop(Looper.java:137) 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.app.ActivityThread.main(ActivityThread.java:4745) 
07-20 00:15:12.789: E/AndroidRuntime(802): at java.lang.reflect.Method.invokeNative(Native Method) 
07-20 00:15:12.789: E/AndroidRuntime(802): at java.lang.reflect.Method.invoke(Method.java:511) 
07-20 00:15:12.789: E/AndroidRuntime(802): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 
07-20 00:15:12.789: E/AndroidRuntime(802): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
07-20 00:15:12.789: E/AndroidRuntime(802): at dalvik.system.NativeStart.main(Native Method) 
07-20 00:15:12.789: E/AndroidRuntime(802): Caused by: java.lang.NullPointerException 
07-20 00:15:12.789: E/AndroidRuntime(802): at com.example.example.mobile.application.gallery.GalleryZoom.LoadImage(GalleryZoom.java:52) 
07-20 00:15:12.789: E/AndroidRuntime(802): at com.example.example.mobile.application.gallery.GalleryZoom.onCreate(GalleryZoom.java:41) 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.app.Activity.performCreate(Activity.java:5008) 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 
07-20 00:15:12.789: E/AndroidRuntime(802): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023) 
07-20 00:15:12.789: E/AndroidRuntime(802): ... 11 more 

任何幫助將是非常讚賞:)和也，這工作得很好在模擬器上2.3.3，但是當最新的4.1跑了，我似乎得到這個錯誤。

Answer 1

你可能有一個NullPointerException這行：

in.close(); 

你流似乎null（壞URL，沒有連接，或STHG這樣）。

試試這個：

InputStream in = null; 
    try { 
     in = OpenHttpConnection(URL); 
     bitmap = BitmapFactory.decodeStream(in, null, options); 

    } catch (IOException e1) { 
    } 
    finally{ 
     try{ 
      in.close(); 
     }catch(Exception e){} 
    } 
    return bitmap;