Java 求从今天向前三天

package com.jie.java.phone;

import java.text.SimpleDateFormat;
import java.util.Calendar;

public class What {
	
	public static void main(String args[]){
		Calendar c = Calendar.getInstance(); 
		c.add(Calendar.DATE,-3); 
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"); 
		String now = sdf.format(c.getTime()); 
		System.out.println(now); 

	}
}