java中有关日期的显示问题

import java.util.*;
import java.text.*;

public class StyleDemo {
  public static void main(String[] args) {
     Date now = new Date();

     DateFormat df = DateFormat.getDateInstance();
     DateFormat df1 = DateFormat.getDateInstance(DateFormat.SHORT);
     DateFormat df2 = DateFormat.getDateInstance(DateFormat.MEDIUM);
     DateFormat df3 = DateFormat.getDateInstance(DateFormat.LONG);
     DateFormat df4 = DateFormat.getDateInstance(DateFormat.FULL);
     String s = df.format(now);
     String s1 = df1.format(now);
     String s2 = df2.format(now);
     String s3 = df3.format(now);
     String s4 = df4.format(now);

     System.out.println("(Default) Today is " + s);
     System.out.println("(SHORT) Today is " + s1);
     System.out.println("(MEDIUM) Today is " + s2);
     System.out.println("(LONG) Today is " + s3);
     System.out.println("(FULL) Today is " + s4);
  }
}