intent服务导致App崩溃

Question

我用过Android服务，我知道它是如何工作的，但我不知道它和IntentService有什么区别。所以我创建了 MyIntentService class 如下所示，但是在运行应用程序崩溃并生成下面发布的 logCat 错误的时间。

请告诉我为什么会收到这些错误以及如何解决

MainActivity

public class MainActivity extends AppCompatActivity {

    private final String TAG = this.getClass().getSimpleName();

    private Button mbtnSend = null;
    private int i = 0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        this.mbtnSend = (Button) findViewById(R.id.btn_send);

        this.mbtnSend.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(getApplicationContext(), MyIntentService.class);
                intent.putExtra("intent_key", ++i);
                startService(intent);
            }
        });

    }
}

MyIntentService:

public class MyIntentService extends IntentService {

    private final String TAG = this.getClass().getSimpleName();

    /**
     * Creates an IntentService.  Invoked by your subclass's constructor.
     *
     * @param name Used to name the worker thread, important only for debugging.
     */
    public MyIntentService(String name) {
        super(name);
        setIntentRedelivery(true);
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Log.w(TAG, SubTag.msg("onCreate"));
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        Log.w(TAG, SubTag.msg("onHandleIntent"));

        int intent_value = intent.getIntExtra("intent_key", -1);
        Log.i(TAG, SubTag.bullet("", "intent_value: " + intent_value));

        SystemClock.sleep(3000);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.w(TAG, SubTag.msg("onStartCommand"));

        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.w(TAG, SubTag.msg("onDestroy"));
    }
}

logcat:

07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime: FATAL EXCEPTION: main
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime: Process: com.example.com.intentservice_00, PID: 18094
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime: java.lang.RuntimeException: Unable to instantiate service com.example.com.intentservice_00.MyIntentService: java.lang.InstantiationException: java.lang.Class<com.example.com.intentservice_00.MyIntentService> has no zero argument constructor
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.app.ActivityThread.handleCreateService(ActivityThread.java:3778)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.app.ActivityThread.access00(ActivityThread.java:223)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1885)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:158)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:7231)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:  Caused by: java.lang.InstantiationException: java.lang.Class<com.example.com.intentservice_00.MyIntentService> has no zero argument constructor
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at java.lang.Class.newInstance(Native Method)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.app.ActivityThread.handleCreateService(ActivityThread.java:3775)
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.app.ActivityThread.access00(ActivityThread.java:223) 
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1885) 
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102) 
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:158) 
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:7231) 
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method) 
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
07-18 11:39:04.081 18094-18094/com.example.com.intentservice_00 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)

Answer 1

试试这个.. 创建默认构造函数

public class MyIntentService extends IntentService{

  public MyIntentService(){ 
       super(null);// That was the lacking constructor
  }
  public MyIntentService(String name) {
      super(name);
  }
//...
}

希望对您有所帮助

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