Java Data Type - 如何将XX：XX上午/下午转换为24小时时钟

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

public class Main {

  public static void main(String[] args) throws Exception {
    // Declare a date format for parsing
    SimpleDateFormat dateParser = new SimpleDateFormat("h:mm a");

    // Parse the time string
    Date date = dateParser.parse("3:30 PM");

    // Declare a date format for printing
    SimpleDateFormat dateFormater = new SimpleDateFormat("HH:mm");

    // Print the previously parsed time
    System.out.println(dateFormater.format(date));
  }
}