E2jiH0 - Online Java Compiler & Debugging Tool

import java.text.*;
import java.util.*;

class Eveniment {
    private Date dataInceput, dataSfarsit;
    private String nume;
    // Primeste 2 stringuri in format yyyy-MM-dd HH:mm:ss reprezentand data si ora
    // de inceput si de final a evenimentului si inca un string care contine numele
    // cu care apare evenimentul in calendar
    public Eveniment(String dataInceput, String dataSfarsit, String nume) {
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try {
            this.dataInceput = format.parse(dataInceput);
            this.dataSfarsit = format.parse(dataSfarsit);
        } catch (Exception e) {
            System.out.println("Data nu este in formatul cerut!");
        }
        this.nume = nume;
    }

    public Date getDataInceput() {
        return dataInceput;
    }

    public Date getDataSfarsit() {
        return dataSfarsit;
    }

    public String getNume() {
        return nume;
    }
}

class EvenimentRecurent extends Eveniment {
    public static final long HOUR_IN_MSEC = 3600000;
    private int numarOre;

    public EvenimentRecurent(String dataInceput, String dataSfarsit, String nume, int numarOre) {
        super(dataInceput, dataSfarsit, nume);
        this.numarOre = numarOre;
    }

    public String urmatorulEveniment(String dataEveniment) {
        SimpleDateFormat formatRecurent = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date timpCurent = getDataInceput();
        try {
            Date timpSpecific = formatRecurent.parse(dataEveniment);
            timpCurent.setTime(timpCurent.getTime() + (timpSpecific.getTime() - timpCurent.getTime()) / (numarOre * HOUR_IN_MSEC) * numarOre * HOUR_IN_MSEC);
            if (timpCurent.before(timpSpecific)) {
                timpCurent.setTime(timpCurent.getTime() + numarOre * HOUR_IN_MSEC);
            }
        } catch (Exception e) {
            System.out.println("Data nu este in formatul cerut!");
            return null;
        }
        return formatRecurent.format(timpCurent).toString();
    }
}

public class Main {
    public static void main(String[] args) {
        EvenimentRecurent er = new EvenimentRecurent("2019-03-09 22:46:00",
                "2019-03-09 23:00:00", "Scris probleme", 24);
        System.out.println(er.urmatorulEveniment("2019-04-19 22:46:23"));
        // 2019-04-20 22:46:00
    }
}