Android doInBackgroundエラー

Question

私はAndroid開発の初心者です。数日前にdoInBackground()メソッドで解決できないというエラーが発生しました。 私のエラーは、私のコードの末尾にある

e2 = e11; 
createInsecureRfcommSocketToServiceRecord = null; 
this.sender = e2.getMessage(); 
createInsecureRfcommSocketToServiceRecord.close(); 

でエラーが

未処理の例外がある：java.io.IO.EXCEPTION

あなたは解決策を持っている場合は、感謝しますあなたは事前に！ マイコード：

protected Object doInBackground(Object[] objArr) { 
    BluetoothSocket createInsecureRfcommSocketToServiceRecord; 
    IOException e; 
    Throwable th; 
    IButton a; 
    Boolean valueOf; 
    boolean z = true; 
    this.jobType = (JobType) objArr[0]; 
    this.sender = (MainActivity) objArr[1]; 
    this.device = (BluetoothDevice) objArr[2]; 
    try { 
     createInsecureRfcommSocketToServiceRecord = 
       device.createInsecureRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB")); 
     try { 
      createInsecureRfcommSocketToServiceRecord.connect(); 
     } catch (IOException e2) { 
      Log.e("Bluetooth", e2.getMessage()); 
      Log.e("Bluetooth", "trying fallback"); 
      try { 
       createInsecureRfcommSocketToServiceRecord = (BluetoothSocket) 
         this.device.getClass().getMethod("createInsecureRfcommSocket", new Class[]{Integer.TYPE}).invoke(this.device, new Object[]{Integer.valueOf(1)}); 
      } catch (Exception e3) { 
       Log.e("Bluetooth", e3.getMessage()); 
      } 
      try { 
       createInsecureRfcommSocketToServiceRecord.connect(); 
      } catch (IOException e4) { 
       e2 = e4; 
       try { 
        this.error = e2.getMessage(); 
        try { 
         createInsecureRfcommSocketToServiceRecord.close(); 
        } catch (IOException e5) { 
        } 
        return null; 
       } catch (Throwable th2) { 
        th = th2; 
        try { 
         createInsecureRfcommSocketToServiceRecord.close(); 
        } catch (IOException e6) { 
        } 
        throw th; 
       } 
      } 
     } 
     if (this.jobType == JobType.read) { 
      a = readDevice(createInsecureRfcommSocketToServiceRecord); 
      try { 
       createInsecureRfcommSocketToServiceRecord.close(); 
       return a; 
      } catch (IOException e7) { 
       return a; 
      } 
     } else 

     if (this.jobType == JobType.stopMission) { 
      a = (IButton) objArr[3]; 
      if (!(stopMission(createInsecureRfcommSocketToServiceRecord) && 
        writeDevice(createInsecureRfcommSocketToServiceRecord, a))) { 
       z = false; 
      } 
      valueOf = Boolean.valueOf(z); 
      try { 
       createInsecureRfcommSocketToServiceRecord.close(); 
       return valueOf; 
      } catch (IOException e8) { 
       return valueOf; 
      } 
     } else 

     if (this.jobType == JobType.startMission) { 
      boolean z2 = writeDevice(createInsecureRfcommSocketToServiceRecord, (IButton) objArr[3]) && 
        startMission(createInsecureRfcommSocketToServiceRecord); 
      valueOf = Boolean.valueOf(z2); 
      try { 
       createInsecureRfcommSocketToServiceRecord.close(); 
       return valueOf; 
      } catch (IOException e9) { 
       return valueOf; 
      } 
     } else { 
      try { 
       createInsecureRfcommSocketToServiceRecord.close(); 
      } catch (IOException e10) { 
      } 
      return null; 
     } 
    } catch (IOException e11) { 
     e2 = e11; 
     createInsecureRfcommSocketToServiceRecord = null; 
     this.sender = e2.getMessage(); 
     createInsecureRfcommSocketToServiceRecord.close(); 
     return null; 
    } catch (Throwable th3) { 
     th = th3; 
     createInsecureRfcommSocketToServiceRecord = null; 
     createInsecureRfcommSocketToServiceRecord.close(); 
     throw th; 
    } 
    return null; 
} 

Answer 1

close()はまた、あなたが処理する必要がIOException例外がスローされます。さらに、finallyブロックをクリーンアップに使用し、nullを閉じる前に変数をNullPointerExeptionに設定しないように注意してください。

あなたは

try { 
    .... 
} catch (Exception e) { 
    .... 
} finally { 
    try { 
     createInsecureRfcommSocketToServiceRecord.close(); 
     createInsecureRfcommSocketToServiceRecord = null; 
    } catch (IOException e) { 
    } 
} 

Answer 2

のようなあなたのコードを向上させることができ、私はこれで私のコードを変更するが、私はjava.lang.NullPointerExceptionがよ... fonction doInBackground（）は非常に困難です... ありがとうございました！

私のコードは、あなたがクリーンアップのために `finally`を使用することを検討すべきである

protected Object doInBackground(Object[] objArr) { 
    BluetoothSocket createInsecureRfcommSocketToServiceRecord = null; 
    IOException e; 
    Throwable th; 
    IButton a; 
    Boolean valueOf; 
    boolean z = true; 
    this.jobType = (JobType) objArr[0]; 
    this.sender = (MainActivity) objArr[1]; 
    this.device = (BluetoothDevice) objArr[2]; 
    try { 
     createInsecureRfcommSocketToServiceRecord = 
       device.createInsecureRfcommSocketToServiceRecord(UUID.fromString("00001101-0000-1000-8000-00805F9B34FB")); 
     try { 
      createInsecureRfcommSocketToServiceRecord.connect(); 
     } catch (IOException e2) { 
      Log.e("Bluetooth", e2.getMessage()); 
      Log.e("Bluetooth", "trying fallback"); 
      try { 
       createInsecureRfcommSocketToServiceRecord = (BluetoothSocket) 
         this.device.getClass().getMethod("createInsecureRfcommSocket", new Class[]{Integer.TYPE}).invoke(this.device, new Object[]{Integer.valueOf(1)}); 
      } catch (Exception e3) { 
       Log.e("Bluetooth", e3.getMessage()); 
      } 
      try { 
       createInsecureRfcommSocketToServiceRecord.connect(); 
      } catch (IOException e4) { 
       e2 = e4; 
       try { 
        this.error = e2.getMessage(); 
        try { 
         createInsecureRfcommSocketToServiceRecord.close(); 
        } catch (IOException e5) { 
        } 
        return null; 
       } catch (Throwable th2) { 
        th = th2; 
        try { 
         createInsecureRfcommSocketToServiceRecord.close(); 
        } catch (IOException e6) { 
        } 
        throw th; 
       } 
      } 
     } 
     if (this.jobType == JobType.read) { 
      a = readDevice(createInsecureRfcommSocketToServiceRecord); 
      try { 
       createInsecureRfcommSocketToServiceRecord.close(); 
       return a; 
      } catch (IOException e7) { 
       return a; 
      } 
     } else if (this.jobType == JobType.stopMission) { 
      a = (IButton) objArr[3]; 
      if (!(stopMission(createInsecureRfcommSocketToServiceRecord) && 
        writeDevice(createInsecureRfcommSocketToServiceRecord, a))) { 
       z = false; 
      } 
      valueOf = Boolean.valueOf(z); 
      try { 
       createInsecureRfcommSocketToServiceRecord.close(); 
       return valueOf; 
      } catch (IOException e8) { 
       return valueOf; 
      } 
     } else if (this.jobType == JobType.startMission) { 
      boolean z2 = writeDevice(createInsecureRfcommSocketToServiceRecord, (IButton) objArr[3]) && 
        startMission(createInsecureRfcommSocketToServiceRecord); 
      valueOf = Boolean.valueOf(z2); 
      try { 
       createInsecureRfcommSocketToServiceRecord.close(); 
       return valueOf; 
      } catch (IOException e9) { 
       return valueOf; 
      } 
     } else { 
      try { 
       createInsecureRfcommSocketToServiceRecord.close(); 
      } catch (IOException e10) { 
      } 
      return null; 
     } 
    } catch (IOException e11) { 
     try { 
      createInsecureRfcommSocketToServiceRecord.close(); 
     } catch (IOException e1) { 
      e1.printStackTrace(); 
     } 
     createInsecureRfcommSocketToServiceRecord = null; 
     return null; 
    } catch (Throwable th3) { 
     th = th3; 
    } finally { 
     try { 
      createInsecureRfcommSocketToServiceRecord.close(); 
      createInsecureRfcommSocketToServiceRecord = null; 
     } catch (IOException e2) { 
     } 
    } 
    return null; 
}