java 对比目标时间与系统时间 ，得出是否今天、昨天

首先用到2个类 ，一个是Date ，一个是Calendar

代码如下

		// 将传入时间与当前时间进行对比，是否今天昨天
		private String getTime(Date date) {
			String todySDF = "今天 HH:mm";
			String yesterDaySDF = "昨天 HH:mm";
			String otherSDF = "M月d日 HH:mm";
			SimpleDateFormat sfd = null;
			String time = "";
			Calendar dateCalendar = Calendar.getInstance();
			dateCalendar.setTime(date);
			Date now = new Date();
			Calendar targetCalendar = Calendar.getInstance();
			targetCalendar.setTime(now);
			targetCalendar.set(Calendar.HOUR_OF_DAY, 0);
			targetCalendar.set(Calendar.MINUTE, 0);
			if (dateCalendar.after(targetCalendar)) {
				sfd = new SimpleDateFormat(todySDF);
				time = sfd.format(date);
				return time;
			} else {
				targetCalendar.add(Calendar.DATE, -1);
				if (dateCalendar.after(targetCalendar)) {
					sfd = new SimpleDateFormat(yesterDaySDF);
					time = sfd.format(date);
					return time;
				}
			}
			sfd = new SimpleDateFormat(otherSDF);
			time = sfd.format(date);
			return time;
		}

注意地方 24小时制 String todySDF = "今天 HH:mm";12小时制为小写 "hh:mm";
同样targetCalendar.set(Calendar.HOUR, 0);为12小时制