java对日期的格式化和自定义

package test_enmu;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/**
 * Created with IntelliJ IDEA.
 * User: @别慌
 * Date: 2019-05-20
 * Time: 21:39
 * Description:
 */
public class week_test {

    public static void main(String arg[]) {
        Calendar calendar =Calendar.getInstance();
        calendar.set(2019,5,12,20,34,34);
        Date date=calendar.getTime();
        SimpleDateFormat dataFormat =new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        System.out.println(dataFormat.format(date));

    }
}