定时任务支持在线生成cron表达式

ruoyi-quartz/src/main/java/com/ruoyi/quartz/controller/SysJobController.java

@@ -11,6 +11,7 @@ import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.ResponseBody;
 import com.ruoyi.common.annotation.Log;
 import com.ruoyi.common.constant.Constants;
@@ -189,4 +190,31 @@ public class SysJobController extends BaseController
     {
         return jobService.checkCronExpressionIsValid(job.getCronExpression());
     }
+
+    /**
+     * Cron表达式在线生成
+     */
+    @GetMapping("/cron")
+    public String cron()
+    {
+        return prefix + "/cron";
+    }
+
+    /**
+     * 查询cron表达式近5次的执行时间
+     */
+    @GetMapping("/queryCronExpression")
+    @ResponseBody
+    public AjaxResult queryCronExpression(@RequestParam(value = "cronExpression", required = false) String cronExpression)
+    {
+        if (jobService.checkCronExpressionIsValid(cronExpression))
+        {
+            List<String> dateList = CronUtils.getRecentTriggerTime(cronExpression);
+            return success(dateList);
+        }
+        else
+        {
+            return error("表达式无效");
+        }
+    }
 }

ruoyi-quartz/src/main/java/com/ruoyi/quartz/util/CronUtils.java

@@ -1,8 +1,13 @@
 package com.ruoyi.quartz.util;
 
 import java.text.ParseException;
+import java.util.ArrayList;
 import java.util.Date;
+import java.util.List;
 import org.quartz.CronExpression;
+import org.quartz.TriggerUtils;
+import org.quartz.impl.triggers.CronTriggerImpl;
+import com.ruoyi.common.utils.DateUtils;
 
 /**
  * cron表达式工具类
@@ -60,4 +65,30 @@ public class CronUtils
             throw new IllegalArgumentException(e.getMessage());
         }
     }
+
+    /**
+     * 通过表达式获取近10次的执行时间
+     * 
+     * @param cron 表达式
+     * @return 时间列表
+     */
+    public static List<String> getRecentTriggerTime(String cron)
+    {
+        List<String> list = new ArrayList<String>();
+        try
+        {
+            CronTriggerImpl cronTriggerImpl = new CronTriggerImpl();
+            cronTriggerImpl.setCronExpression(cron);
+            List<Date> dates = TriggerUtils.computeFireTimes(cronTriggerImpl, null, 10);
+            for (Date date : dates)
+            {
+                list.add(DateUtils.parseDateToStr(DateUtils.YYYY_MM_DD_HH_MM_SS, date));
+            }
+        }
+        catch (ParseException e)
+        {
+            return null;
+        }
+        return list;
+    }
 }