java 日期计算

代码来自：    http://wenda.so.com/q/1364964025066182

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

public class NDays {
public static void main(String[] args) {
Date date = new Date();
System.out.println((new SimpleDateFormat("yyyy-MM-dd")).format(date));
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.add(Calendar.DATE, 100);
System.out.println((new SimpleDateFormat("yyyy-MM-dd")).format(cal.getTime()));
}
}