java获得当前时间一小时前的时间详解编程语言

 
Calendar calendar = Calendar.getInstance(); 
		calendar.setTime(new Date()); 
		calendar.set(Calendar.HOUR, 
				calendar.get(Calendar.HOUR) - 1);// 让日期加1 
		System.out.println(calendar.get(Calendar.DATE));// 加1之后的日期Top 
		System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SS").format(calendar.getTime()));