Esercizi per l'inserimento di date come Long nel database

Conversione di data, da formato String a formato Date a Long (tempo quello dell'epoch...).
Facciamo il mio compleanno, vah...

Intanto mi salvo il codice con cui stavo giocherellando ieri sera perché mi potrebbe servire, non essendo ancora esperto di questa roba...

public class MainActivity extends AppCompatActivity {

    CalendarView calendarView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        calendarView=(CalendarView) findViewById(R.id.calendarView);

        Calendar calendar= Calendar.getInstance();
        SimpleDateFormat sdf=new SimpleDateFormat("dddd/MM/yyyy");
        String strDate="10/2/2016";
        try {
            Date myDate = sdf.parse(strDate);
            calendar.setTime(myDate);
        }catch(Exception e){}
        System.out.println("VALORE "+calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
        calendar.set(Calendar.DAY_OF_MONTH,calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
        calendarView.setMaxDate(calendar.getTimeInMillis());




    }
}

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Bene.
Vado. Da String a Date e quindi a Calendar.

public class MainActivity extends AppCompatActivity {

    CalendarView calendarView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Date myDate;
        String strDate="5/9/1961";
        Calendar calendar= Calendar.getInstance();
        SimpleDateFormat sdf=new SimpleDateFormat("dd/MM/yyyy");
        try{
            myDate=sdf.parse(strDate);
            calendar.setTime(myDate);
            System.out.println(calendar.getTimeInMillis());
        }catch(Exception e){}
    }
}

Usando il tempo in millisecondi dalla Linux Epoch:

public class MainActivity extends AppCompatActivity {

    CalendarView calendarView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Date myDate;
        String strDate="5/9/1961";
        Calendar calendar= Calendar.getInstance();
        SimpleDateFormat sdf=new SimpleDateFormat("dd/MM/yyyy");
        try{
            myDate=sdf.parse(strDate);
            calendar.setTime(myDate);
            Long numero=calendar.getTimeInMillis();

            calendar.setTimeInMillis(numero);
            Date secondDate=calendar.getTime();
            String str=sdf.format(secondDate);
            System.out.println("VALORE "+str);
        }catch(Exception e){}
    }
}

che funziona:

10-16 04:09:33.976 2276-2276/? I/System.out: VALORE 05/09/1961

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Bene. Ora metto in un database diverse date.
Creo il database...

Ho creato la classe del database:

    public class Helper extends SQLiteOpenHelper {

        public Helper(Context context) {
            super(context, "database.db",null, 1);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL("create tabella(data integer)");
        }

        public void save(long dat){
            SQLiteDatabase db=this.getWritableDatabase();
            ContentValues values=new ContentValues();
            values.put("data",dat);
            db.insert("tabella",null,values);
        }

        public Cursor query(){
            SQLiteDatabase db=this.getWritableDatabase();
            Cursor crs=db.rawQuery("select* from tabella",null);
            crs.moveToFirst();
            return crs;
        }

        @Override
        public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

        }
    }

Istanzio un oggetto database come al solito...

Helper helper;

.....

helper=new Helper(this);

Ora voglio inserire quattro date sotto forma di numeri Long.
Parto dalle stringhe.
Fatto.
Ecco il codice:

public class MainActivity extends AppCompatActivity {

    CalendarView calendarView;
    Helper helper;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        helper=new Helper(this);
        Date myDate;
        Long numero=0l;
        String[] matrice={"5/9/1961","13/6/1962","10/1/2003","10/2/1935"};
        for(String elemento : matrice){
            System.out.println("Stringa "+elemento);
            SimpleDateFormat sdf=new SimpleDateFormat("dddd/MM/yyyy");
            try {
                myDate = sdf.parse(elemento);
                numero=myDate.getTime();
                System.out.println("NUMERO "+numero);
                helper.save(numero);

            }catch(Exception e){}


        }

    }

    class Helper extends SQLiteOpenHelper {

        public Helper(Context context) {
            super(context, "database.db",null, 1);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            db.execSQL("create table tabella(data integer)");
        }

        public void save(long dat){
            SQLiteDatabase db=this.getWritableDatabase();
            ContentValues values=new ContentValues();
            values.put("data",dat);
            db.insert("tabella",null,values);
        }

        public Cursor query(){
            SQLiteDatabase db=this.getWritableDatabase();
            Cursor crs=db.rawQuery("select* from tabella",null);
            crs.moveToFirst();
            return crs;
        }

        @Override
        public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

        }
    }
}