Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, 16); // 时
calendar.set(Calendar.MINUTE, 17);// 分
calendar.set(Calendar.SECOND, 00); // 秒
Date date = calendar.getTime(); // 第一次执行定时任务的时间
// 如果第一次执行定时任务的时间 小于当前的时间
// 判断时间是否已经过了(也是时间比较)
if (date.before(new Date())) {
calendar.add(Calendar.DAY_OF_MONTH, 1);
date = this.addDay(date, 1);
}
//时间的加一天还是减一天
public static Date addDay(Date date, int num) {
Calendar startDT = Calendar.getInstance();
startDT.setTime(date);
startDT.add(Calendar.DAY_OF_MONTH, num);
return startDT.getTime();
}
//时间比较前后
public static void compareTime() {
String s1 = "2009-01-25 09:12:09";
String s2 = "2008-01-29 09:12:11";
SimpleDateFormat df = SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
java.util.Calendar c1 = java.util.Calendar.getInstance();
java.util.Calendar c2 = java.util.Calendar.getInstance();
try {
c1.setTime(df.parse(s1));
c2.setTime(df.parse(s2));
} catch (java.text.ParseException e) {
System.err.println("格式不正确");
}
int result = c1.compareTo(c2);
System.out.println(result);
if (result == 0)
System.out.println("c1相等c2");
else if (result < 0)
System.out.println("c1小于c2");
else
System.out.println("c1大于c2");
}