Java Data Type - 如何通过传递特定日期确定星期几

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

public class Main {
  public static void main(String args[]) {
    SimpleDateFormat df = new SimpleDateFormat("dd/MM/yy");
    java.util.Date date = new Date();
    df.applyPattern("EEE");
    String day = df.format(date);
    if (day.compareTo("Sat") == 0 || day.compareTo("Sun") == 0) {
      System.out.println(day + ": Weekend");
    } else {
      System.out.println(day + ": Weekday");
    }
  }
}