java - 每天执行android studio

Question

我每天早上都试着运行这个。我该怎么做才能让我每天做一次。下面是我的代码，但它不起作用。

public final class FetchMail extends TimerTask {
DatabaseHelper myDb;
SQLiteDatabase db = myDb.getReadableDatabase();


public static void main (String... arguments ) {
    TimerTask fetchMail = new FetchMail();

    Timer timer = new Timer();
    timer.scheduleAtFixedRate(fetchMail, getTomorrowMorning4am(), fONCE_PER_DAY);
}


@Override
public void run(){

    Cursor t = db.rawQuery("SELECT ID_TARGET,TARGET,LEAD_TIME FROM TARGET_TABLE WHERE (LEAD_TIME < date('now')) AND AMOUNT > 0", null);

if (t != null ) {
    if  (t.moveToFirst()) {
        do {

            String tmpName = t.getString(t.getColumnIndex("TARGET"));


            String selectQuery = ("INSERT INTO GAMIFICATION(ID,HISTORY,STATE_POINTS) VALUES(NULL,'Points: " + tmpName + "',-1)");
            db.execSQL(selectQuery);




        }while (t.moveToNext());
    }
} 

}


private final static long fONCE_PER_DAY = 1000*60*60*24;

private final static int fONE_DAY = 1;
private final static int fFOUR_AM = 4;
private final static int fZERO_MINUTES = 0;

private static Date getTomorrowMorning4am(){
    Calendar tomorrow = new GregorianCalendar();
    tomorrow.add(Calendar.DATE, fONE_DAY);
    Calendar result = new GregorianCalendar(
            tomorrow.get(Calendar.YEAR),
            tomorrow.get(Calendar.MONTH),
            tomorrow.get(Calendar.DATE),
            fFOUR_AM,
            fZERO_MINUTES
    );
    return result.getTime();
}}

我必须向 MainActivity 添加一些东西吗？因为 MainActivity 是第一页。

Answer 1

我认为您的问题是“如何运行预定的后台任务”？依赖 Activity 将无济于事，因为 Activity 需要可见才能运行(请参阅带有 Activity 文档的状态表。您可能会更高兴有背景 Service 并从 Application

祝你好运。