Pari Pari - 4 months ago 16
Java Question

No empty constructor when create a service

I am struggling with this error:


08-08 11:42:53.179: E/AndroidRuntime(20288): Caused by: java.lang.InstantiationException: can't instantiate class com.example.localnotificationtest.ReminderService; no empty constructor


I don't understand why this error occurs.

I am trying to appear notification at specific time and after searching for a time i found this old stackoverflow question. I tried everything but my code gives error.

Please help me to solve this problem.

Here is my MainActivity code:

public class MainActivity extends Activity {
int mHour, mMinute;
ReminderService reminderService;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
reminderService = new ReminderService("ReminderService");

TimePickerDialog dialog = new TimePickerDialog(this, mTimeSetListener, mHour, mMinute, false);
dialog.show();
}

TimePickerDialog.OnTimeSetListener mTimeSetListener = new OnTimeSetListener() {

@Override
public void onTimeSet(TimePicker v, int hourOfDay, int minute) {
mHour = hourOfDay;
mMinute = minute;

AlarmManager alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
Calendar c = Calendar.getInstance();
c.set(Calendar.YEAR, Calendar.YEAR);
c.set(Calendar.MONTH, Calendar.MONTH);
c.set(Calendar.DAY_OF_MONTH, Calendar.DAY_OF_MONTH);
c.set(Calendar.HOUR_OF_DAY, mHour);
c.set(Calendar.MINUTE, mMinute);
c.set(Calendar.SECOND, 0);

long timeInMills = c.getTimeInMillis();

Intent intent = new Intent(MainActivity.this, ReminderService.class);
PendingIntent pendingIntent = PendingIntent.getService(MainActivity.this, 0, intent, 0);
alarmManager.set(AlarmManager.RTC, timeInMills, pendingIntent);
}
};

}


and here is my ReminderService code:

public class ReminderService extends IntentService {

public ReminderService(String name) {
super(name);
// TODO Auto-generated constructor stub
}

@Override
protected void onHandleIntent(Intent intent) {

Intent notificationIntent = new Intent(this, MainActivity.class);
PendingIntent contentIntent = PendingIntent.getActivity(this, 1, notificationIntent, PendingIntent.FLAG_CANCEL_CURRENT);

NotificationManager nm = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);

Notification.Builder builder = new Notification.Builder(this);

builder.setContentIntent(contentIntent)
.setSmallIcon(R.drawable.ic_launcher)
.setTicker("Local Notification Ticker")
.setWhen(System.currentTimeMillis())
.setAutoCancel(true)
.setContentTitle("Local Notification")
.setContentText("This is content text.");
Notification n = builder.getNotification();

nm.notify(1, n);
}

}


and here is my manifest.xml:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.localnotificationtest"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="15" />

<application
android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" >
<activity android:name=".MainActivity" android:label="@string/title_activity_main" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name="ReminderService"></service>
</application>

</manifest>


I don't know where I am going wrong. Am I missing some code?

Answer

You need to add an empty constructor to your class i.e. one that takes no arguments:

public ReminderService() {
    super("ReminderService");
}

Explanation from the documentation:

The name is used to name the worker thread.

NOTE: this is only applicable to intent service.

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