add preview schedule

escheduler-api/src/main/java/cn/escheduler/api/controller/SchedulerController.java

@@ -304,4 +304,33 @@ public class SchedulerController extends BaseController {
             return error(Status.QUERY_SCHEDULE_LIST_ERROR.getCode(), Status.QUERY_SCHEDULE_LIST_ERROR.getMsg());
         }
     }
+
+    /**
+     * preview schedule
+     *
+     * @param loginUser
+     * @param projectName
+     * @param schedule
+     * @return
+     */
+    @ApiOperation(value = "previewSchedule", notes= "PREVIEW_SCHEDULE_NOTES")
+    @ApiImplicitParams({
+            @ApiImplicitParam(name = "schedule", value = "SCHEDULE", dataType = "String", example = "{'startTime':'2019-06-10 00:00:00','endTime':'2019-06-13 00:00:00','crontab':'0 0 3/6 * * ? *'}"),
+    })
+    @PostMapping("/preview")
+    @ResponseStatus(HttpStatus.CREATED)
+    public Result previewSchedule(@ApiIgnore @RequestAttribute(value = SESSION_USER) User loginUser,
+                                 @ApiParam(name = "projectName", value = "PROJECT_NAME", required = true) @PathVariable String projectName,
+                                 @RequestParam(value = "schedule") String schedule
+    ){
+        logger.info("login user {}, project name: {}, preview schedule: {}",
+                loginUser.getUserName(), projectName, schedule);
+        try {
+            Map<String, Object> result = schedulerService.previewSchedule(loginUser, projectName, schedule);
+            return returnDataList(result);
+        } catch (Exception e) {
+            logger.error(PREVIEW_SCHEDULE_ERROR.getMsg(), e);
+            return error(PREVIEW_SCHEDULE_ERROR.getCode(), PREVIEW_SCHEDULE_ERROR.getMsg());
+        }
+    }
 }

escheduler-api/src/main/java/cn/escheduler/api/service/SchedulerService.java

@@ -19,14 +19,13 @@ package cn.escheduler.api.service;
 
 import cn.escheduler.api.dto.ScheduleParam;
 import cn.escheduler.api.enums.Status;
-import cn.escheduler.server.quartz.ProcessScheduleJob;
-import cn.escheduler.server.quartz.QuartzExecutors;
 import cn.escheduler.api.utils.Constants;
 import cn.escheduler.api.utils.PageInfo;
 import cn.escheduler.common.enums.FailureStrategy;
 import cn.escheduler.common.enums.Priority;
 import cn.escheduler.common.enums.ReleaseState;
 import cn.escheduler.common.enums.WarningType;
+import cn.escheduler.common.utils.DateUtils;
 import cn.escheduler.common.utils.JSONUtils;
 import cn.escheduler.dao.ProcessDao;
 import cn.escheduler.dao.mapper.MasterServerMapper;
@@ -34,7 +33,11 @@ import cn.escheduler.dao.mapper.ProcessDefinitionMapper;
 import cn.escheduler.dao.mapper.ProjectMapper;
 import cn.escheduler.dao.mapper.ScheduleMapper;
 import cn.escheduler.dao.model.*;
+import cn.escheduler.dao.utils.cron.CronUtils;
+import cn.escheduler.server.quartz.ProcessScheduleJob;
+import cn.escheduler.server.quartz.QuartzExecutors;
 import org.apache.commons.lang3.StringUtils;
+import org.quartz.CronExpression;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -42,6 +45,7 @@ import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 import java.io.IOException;
+import java.text.ParseException;
 import java.util.*;
 
 /**
@@ -537,4 +541,32 @@ public class SchedulerService extends BaseService {
         }
         return result;
     }
+
+    /**
+     * preview schedule
+     * @param loginUser
+     * @param projectName
+     * @param schedule
+     * @return
+     */
+    public Map<String,Object> previewSchedule(User loginUser, String projectName, String schedule) {
+        Map<String, Object> result = new HashMap<>(5);
+        CronExpression cronExpression;
+        ScheduleParam scheduleParam = JSONUtils.parseObject(schedule, ScheduleParam.class);
+        Date now = new Date();
+
+        Date startTime = now.after(scheduleParam.getStartTime()) ? now : scheduleParam.getStartTime();
+        Date endTime = scheduleParam.getEndTime();
+        try {
+            cronExpression = CronUtils.parse2CronExpression(scheduleParam.getCrontab());
+        } catch (ParseException e) {
+            logger.error(e.getMessage(),e);
+            putMsg(result,Status.PARSE_TO_CRON_EXPRESSION_ERROR);
+            return result;
+        }
+        List<Date> selfFireDateList = CronUtils.getSelfFireDateList(startTime, endTime,cronExpression);
+        result.put(Constants.DATA_LIST, selfFireDateList.stream().map(t -> DateUtils.dateToString(t)).limit(cn.escheduler.common.Constants.PREVIEW_SCHEDULE_EXECUTE_COUNT));
+        putMsg(result, Status.SUCCESS);
+        return result;
+    }
 }