In this source code example, we will you how to format a Date or LocalDateTime into yyyy-MM-dd HH:mm:ss format in Java.

Java format Date to yyyy-MM-dd HH:mm:ss

import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Date;

public class Main {

    public static void main(String[] args) {

        System.out.println("Before JDK 8:");
        // yyyy-MM-dd
        Date date = new Date();
        
        SimpleDateFormat formatterD1 = new SimpleDateFormat("yyyy-MM-dd");
        String d1 = formatterD1.format(date);
        System.out.println(d1);
        
        // yyyy-MM-dd HH:mm:ss
        SimpleDateFormat formatterD2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String d2 = formatterD2.format(date);
        System.out.println(d2);
        
        System.out.println("\nStarting with JDK 8:");
        
        // yyyy-MM-dd
        LocalDate localDate = LocalDate.now();
        DateTimeFormatter formatterLocalDate = DateTimeFormatter.ofPattern("yyyy-MM-dd");
        String ld1 = formatterLocalDate.format(localDate);
        System.out.println(ld1);
        
        // yyyy-MM-dd HH:mm:ss
        LocalDateTime localDateTime = LocalDateTime.now();
        DateTimeFormatter formatterLocalDateTime = 
                DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        String ldt1 = formatterLocalDateTime.format(localDateTime);
        System.out.println(ldt1);
    }

}

Output:

Before JDK 8:
2021-11-10
2021-11-10 16:54:22

Starting with JDK 8:
2021-11-10
2021-11-10 16:54:22