在Facebook上分享時出現空指針異常

Question

我使用下面的代碼來分享FaceBook share.The圖片張貼在某些FaceBook ID中但有一定的FaceBook ID我得到空指針異常。我該如何解決這個問題。

postParams.putString("message", message); 
    postParams.putString("picture",picture); 
    System.out.println("******* 111111 *********"); 

    com.facebook.Request.Callback callback = new com.facebook.Request.Callback() 
    { 
    public void onCompleted(Response response) 
     { 
     JSONObject graphResponse =response.getGraphObject().getInnerJSONObject(); 
     String postId = null; 
     try { 
     postId = graphResponse.getString("id"); 
     } catch (JSONException e) 
     { 
     Log.i("postthis", "JSON error " + e.getMessage()); 
     } 
     FacebookRequestError error = response.getError(); 
     if (error != null) { 
      Log.i("postthis", "JSON error "  +error.getErrorMessage()); 
      } 
     else { 
//  Toast.makeText(ctx.getApplicationContext(), postId, 
//      Toast.LENGTH_LONG).show(); 
      } 
      } 
      }; 

這是logcat錯誤：

01-22 09:43:20.812: E/AndroidRuntime(5201): FATAL EXCEPTION: main 
01-22 09:43:20.812: E/AndroidRuntime(5201): java.lang.NullPointerException 
01-22 09:43:20.812: E/AndroidRuntime(5201):  at FBLogin$2.onCompleted (FBLogin.java:316) 
01-22 09:43:20.812: E/AndroidRuntime(5201):  at com.facebook.Request$4.run(Request.java:1669) 
01-22 09:43:20.812: E/AndroidRuntime(5201):  at android.os.Handler.handleCallback(Handler.java:615) 
01-22 09:43:20.812: E/AndroidRuntime(5201):  at android.os.Handler.dispatchMessage(Handler.java:92) 
01-22 09:43:20.812: E/AndroidRuntime(5201):  at android.os.Looper.loop(Looper.java:137) 
01-22 09:43:20.812: E/AndroidRuntime(5201):  at android.app.ActivityThread.main(ActivityThread.java:4895) 
01-22 09:43:20.843: E/android.os.Debug(353): !@Dumpstate > dumpstate -k -t -z -d -o /data/log/dumpstate_app_error 

Answer 1

檢查您的參數，如果該參數的任何一個爲null，則圖形對象顯示在Facebook分享空值。

Answer 2

張貼在牆上的會話是空所以你必須主動會話首次張貼在牆上的空指針異常。您可以使用以下代碼在牆上分享。

Session.openActiveSession(activity, true, new Session.StatusCallback() { 

    // callback when session changes state 
    @Override 
    public void call(Session session, SessionState state, 
      Exception exception) { 
     if (session != null && session.isOpened()) { 

      // Check for publish permissions 
      List<String> permissions = session.getPermissions(); 
      if (!isSubsetOf(PERMISSIONS, permissions)) { 
       Session.NewPermissionsRequest newPermissionsRequest = new Session.NewPermissionsRequest(
         activity, PERMISSIONS); 
       session.requestNewPublishPermissions(newPermissionsRequest); 
       return; 
      } 

      Bundle postParams = new Bundle(); 
      postParams.putString("message", message); 

       postParams.putString("tags",tag); 
        postParams.putString("place",place_id); 



      Request.Callback callback = new Request.Callback() { 
       private String toastmessage; 

       public void onCompleted(Response response) { 
        try { 
         JSONObject graphResponse = response 
           .getGraphObject().getInnerJSONObject(); 
         String postId = null; 

         postId = graphResponse.getString("id"); 
        } catch (Exception e) { 
         Log.i("Test", "JSON error " + e.getMessage()); 
        } 
        FacebookRequestError error = response.getError(); 
        if (error != null) { 
         isPosted(false); 
         Toast.makeText(
           activity.getApplicationContext(), 
           error.getErrorMessage(), 
           Toast.LENGTH_SHORT).show(); 
        } else { 
         isPosted(true); 
         toastmessage = "Posted Successfully"; 
         Toast.makeText(activity, toastmessage, 
           Toast.LENGTH_SHORT).show(); 
         { 

         } 
        } 
       } 
      }; 

      Request request = new Request(session, "me/feed", 
        postParams, HttpMethod.POST, callback); 

      RequestAsyncTask task = new RequestAsyncTask(request); 
      task.execute(); 
     } 


    } 
}); 

鑑於在此鏈接How do I publish a check in to facebook with android SDK

Answer 3

一旦試試這個，這是爲我工作在Android sdk 3.x

void publishToWall(Session session) {  
    if (session != null) {   
     Bundle postParams = new Bundle(); 
     postParams.putString("message", "contentStr"); 
     postParams.putString("description", "description"); 
     postParams.putString("link", ""); 
     postParams.putString("name", "Name"); 
     postParams.putString("picture", "picture url"); 

     Request.Callback callback = new Request.Callback() { 
      public void onCompleted(Response response) {  

      } 
     }; 
     Request request = new Request(session, "me/feed", postParams, HttpMethod.POST, callback); 
     RequestAsyncTask task = new RequestAsyncTask(request); 
     task.execute();    

     Log.i("TAG", "Message posted to your facebook wall!..");   


    }   
}