From 1501514857255d2ffc3ac58bad671b3d88218db6 Mon Sep 17 00:00:00 2001
From: 王明元 <97082371@qq.com>
Date: Fri, 27 May 2022 15:08:04 +0800
Subject: [PATCH] 2022年5月27日15:07:24 cron表达式执行时间计算

---
 src/main/java/cn/fw/freya/utils/CronCheckUtil.java | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/src/main/java/cn/fw/freya/utils/CronCheckUtil.java b/src/main/java/cn/fw/freya/utils/CronCheckUtil.java
index 52c85fb..ad6d9da 100644
--- a/src/main/java/cn/fw/freya/utils/CronCheckUtil.java
+++ b/src/main/java/cn/fw/freya/utils/CronCheckUtil.java
@@ -1,18 +1,20 @@
 package cn.fw.freya.utils;
 
-import org.springframework.scheduling.support.CronSequenceGenerator;
+import org.springframework.scheduling.support.CronExpression;
 
-import java.text.SimpleDateFormat;
-import java.util.*;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
 
 /**
  * @author wmy3969
  * @version 1.0
  * @date 2021/10/05 17:30
- * @Description cron表达式校验工具类
+ * @Description cron表达式执行时间校验工具类
  */
 public class CronCheckUtil {
-
     /**
      * 根据cron表达式, 获取在某个时间点之后的counter次执行时间列表
      *
@@ -21,15 +23,15 @@ public class CronCheckUtil {
      * @param counter        执行次数
      * @return
      */
-    public static List<Date> getRuntimeList(String cronExpression, Date startDate, int counter) {
-        List<Date> timeList = new ArrayList(counter);
-        Calendar calendar = new GregorianCalendar();
-        TimeZone timeZone = calendar.getTimeZone();
-        CronSequenceGenerator cronSequenceGenerator = new CronSequenceGenerator(cronExpression, timeZone);
-        Date next = cronSequenceGenerator.next(startDate);
-        for (int i = 0; i < counter; i++) {
-            timeList.add(next);
-            next = cronSequenceGenerator.next(next);
+    public static List<LocalDateTime> getRuntimeList(String cronExpression, LocalDateTime startDate, int counter) {
+        final int cnt = Math.max(counter, 1);
+        ArrayList<LocalDateTime> timeList = new ArrayList<LocalDateTime>(cnt);
+        CronExpression expression = CronExpression.parse(cronExpression);
+        LocalDateTime nextTime = Objects.isNull(startDate) ? LocalDateTime.now() : startDate;
+        for (int i = 0; i < cnt; i++) {
+            assert nextTime != null;
+            nextTime = expression.next(nextTime);
+            timeList.add(nextTime);
         }
         return timeList;
     }
@@ -40,8 +42,8 @@ public class CronCheckUtil {
      * @param args
      */
     public static void main(String[] args) {
-        final List<Date> runtimeList = CronCheckUtil.getRuntimeList("0 0/2 * * * ?", new Date(), 300);
-        final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss mmm");
-        runtimeList.forEach(item -> System.out.println(sdf.format(item)));
+        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
+        final List<LocalDateTime> runtimeList = CronCheckUtil.getRuntimeList("0 0/2 * * * ?", LocalDateTime.now(), 10);
+        runtimeList.forEach(item -> System.out.println(dateTimeFormatter.format(item)));
     }
 }
--
libgit2 0.22.2