1.用java.util.Calender来实现
Calendar calendar=Calendar.getInstance()
calendar.setTime(new Date())
System.out.println(calendar.get(Calendar.DAY_OF_MONTH))
calendar.set(Calendar.DAY_OF_MONTH,calendar.get(Calendar.DAY_OF_MONTH)+1)
System.out.println(calendar.get(Calendar.DATE))
2.用java.text.SimpleDateFormat和java.util.Date来实现
Date d=new Date()
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd")
System.out.println("今天的日期:"+df.format(d))
System.out.println("两天前的日期:" + df.format(new Date(d.getTime() - 2 * 24 * 60 * 60 * 1000)))
System.out.println("三天后的日期:" + df.format(new Date(d.getTime() + 3 * 24 * 60 * 60 * 1000)))