Here's a Java program to get the current date and time:

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class Main {
    public static void main(String[] args) {
        LocalDateTime now = LocalDateTime.now();
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        String formattedDateTime = now.format(formatter);
        System.out.println("Current Date and Time: " + formattedDateTime);
    }
}

This program uses the LocalDateTime class to get the current date and time. The LocalDateTime.now() method returns an instance of LocalDateTime representing the current date and time.

We then use a DateTimeFormatter to format the date and time as a string. In this example, we are using the format "yyyy-MM-dd HH:mm:ss", which will produce a string that looks like "2023-02-16 12:34:56".

Finally, we print the formatted date and time to the console using System.out.println().

This program can be customized to use different date/time formats or to perform additional date/time calculations.