How insert Event in calnder without using intent in Android?

Question

Here is code: i am trying to add event to calender without using intent..here i put code.but getting some error.help me out.and got null pointer exception as given below.what to do now?

 btn_create_without_intent.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // Construct event details
            long startMillis = 0;
            long endMillis = 0;
            Calendar beginTime = Calendar.getInstance();
            beginTime.set(2015, 9, 21, 7, 30);
            startMillis = beginTime.getTimeInMillis();
            Calendar endTime = Calendar.getInstance();
            endTime.set(2015, 9, 21, 8, 45);
            endMillis = endTime.getTimeInMillis();

            // Insert Event
            ContentResolver cr = getContentResolver();
            ContentValues values = new ContentValues();
            TimeZone timeZone = TimeZone.getDefault();
            values.put(CalendarContract.Events.DTSTART, startMillis);
            values.put(CalendarContract.Events.DTEND, endMillis);
            values.put(CalendarContract.Events.EVENT_TIMEZONE, timeZone.getID());
            values.put(CalendarContract.Events.TITLE, "Android Example");
            values.put(CalendarContract.Events.DESCRIPTION, "Android Example");
            values.put(CalendarContract.Events.CALENDAR_ID, 3);
            Uri uri = cr.insert(CalendarContract.Events.CONTENT_URI, values);

            // Retrieve ID for new event
            String eventID = uri.getLastPathSegment();
        }
    });

And getting this error:

E/DatabaseUtils﹕ Writing exception to parcel
java.lang.NullPointerException
        at com.android.providers.calendar.CalendarProvider2.insertInTransaction(CalendarProvider2.java:2523)
        at com.android.providers.calendar.SQLiteContentProvider.insert(SQLiteContentProvider.java:96)
        at android.content.ContentProvider$Transport.insert(ContentProvider.java:192)
        at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:152)
        at android.os.Binder.execTransact(Binder.java:338)
        at dalvik.system.NativeStart.run(Native Method)
java.lang.NullPointerException
        at android.os.Parcel.readException(Parcel.java:1333)
        at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:182)
        at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:136)
        at android.content.ContentProviderProxy.insert(ContentProviderNative.java:415)
        at android.content.ContentResolver.insert(ContentResolver.java:730)
        at mockapp.techforce.com.calendereventexample.MainActivity$1.onClick(MainActivity.java:52)
        at android.view.View.performClick(View.java:3571)
        at android.view.View$PerformClick.run(View.java:14247)
        at android.os.Handler.handleCallback(Handler.java:605)
        at android.os.Handler.dispatchMessage(Handler.java:92)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:4517)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
        at dalvik.system.NativeStart.main(Native Method)