为什么下面的cron表达式运行所有操作，而不是每周六凌晨1点运行一次？

我想确保我的Cron表达式每周六凌晨1点只运行一次。我已经编写了以下代码来验证它，但看起来它将每分钟触发一次：

import org.quartz.CronExpression;

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

public class Main {

    public static void main(String[] args) throws ParseException {
        CronExpression exp = new CronExpression("0 0 1 ? * SAT");
        Calendar calendar = Calendar.getInstance();
        calendar.set(2014, Calendar.JANUARY, 1, 1, 0, 0);

        Date date = calendar.getTime();
        for (int day = 1; day < 31; day++) {
            date = exp.getNextInvalidTimeAfter(date);
            System.out.println("date = " + date);
        }
    }
}

你知道Cron表达式有什么问题吗？正确的表达式是什么

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谢谢。

Duh！我使用了错误的方法getNextInvalidTimeAfter，而不是getNextValidTimeAfter

date = Wed Jan 01 01:00:01 GMT 2014
date = Wed Jan 01 01:00:02 GMT 2014
date = Wed Jan 01 01:00:03 GMT 2014
date = Wed Jan 01 01:00:04 GMT 2014
date = Wed Jan 01 01:00:05 GMT 2014
date = Wed Jan 01 01:00:06 GMT 2014
date = Wed Jan 01 01:00:07 GMT 2014
date = Wed Jan 01 01:00:08 GMT 2014
date = Wed Jan 01 01:00:09 GMT 2014
date = Wed Jan 01 01:00:10 GMT 2014
date = Wed Jan 01 01:00:11 GMT 2014
date = Wed Jan 01 01:00:12 GMT 2014
date = Wed Jan 01 01:00:13 GMT 2014
date = Wed Jan 01 01:00:14 GMT 2014
date = Wed Jan 01 01:00:15 GMT 2014
date = Wed Jan 01 01:00:16 GMT 2014
date = Wed Jan 01 01:00:17 GMT 2014
date = Wed Jan 01 01:00:18 GMT 2014
date = Wed Jan 01 01:00:19 GMT 2014
date = Wed Jan 01 01:00:20 GMT 2014
date = Wed Jan 01 01:00:21 GMT 2014
date = Wed Jan 01 01:00:22 GMT 2014
date = Wed Jan 01 01:00:23 GMT 2014
date = Wed Jan 01 01:00:24 GMT 2014
date = Wed Jan 01 01:00:25 GMT 2014
date = Wed Jan 01 01:00:26 GMT 2014
date = Wed Jan 01 01:00:27 GMT 2014
date = Wed Jan 01 01:00:28 GMT 2014
date = Wed Jan 01 01:00:29 GMT 2014
date = Wed Jan 01 01:00:30 GMT 2014