一般在写定时任务的时候都是后台定义好的定时时间，但根据不同的项目需求需要客户去配置某个时间段的定时，把操作权给用户 所以就需要后端人员通过前端传值的方式来实现定时任务配置;
补充一下core表达式官网:https://cron.qqe2.com/
先看一下项目的原型图
类似于core表达式官网的效果，我查询了一下core表达式官网的配置发现他们通过JS进行拼接的方式;
相对于我们来说更倾向于后台去拼接这样的话能保证表达式正确性，前端也比较费时费力；以下就是后端的解决方案:
TaskScheduleModel.java
public class TaskScheduleModel {
/**
* 所选作业类型:
* 0 ->每次
* 1 -> 每天
* 2 -> 每月
* 3 -> 每周
* 4 ->间隔（每隔2个小时，每隔30分钟）
*/
Integer jobType;
/**一周的哪几天*/
Integer[] dayOfWeeks;
/**一个月的哪几天*/
Integer[] dayOfMonths;
/**秒 */
Integer second;
/**分 */
Integer minute;
/**时 */
Integer hour;
Integer beApart;
public Integer getBeApart() {
return beApart;
}
public void setBeApart(Integer beApart) {
this.beApart = beApart;
}
public Integer getJobType() {
return jobType;
}
public void setJobType(Integer jobType) {
this.jobType = jobType;
}
public Integer[] getDayOfWeeks() {
return dayOfWeeks;
}
public void setDayOfWeeks(Integer[] dayOfWeeks) {
this.dayOfWeeks = dayOfWeeks;
}
public Integer[] getDayOfMonths() {
return dayOfMonths;
}
public void setDayOfMonths(Integer[] dayOfMonths) {
this.dayOfMonths = dayOfMonths;
}
public Integer getSecond() {
return second;
}
public void setSecond(Integer second) {
this.second = second;
}
public Integer getMinute() {
return minute;
}
public void setMinute(Integer minute) {
this.minute = minute;
}
public Integer getHour() {
return hour;
}
public void setHour(Integer hour) {
this.hour = hour;
}
}
公共方法:
/**
* @ClassName: CronUtil
* @Description: Cron表达式工具类
* 目前支持三种常用的cron表达式
* 1.每天的某个时间点执行 例:12 12 12 * * ?表示每天12时12分12秒执行
* 2.每周的哪几天执行 例:12 12 12 ? * 1,2,3表示每周的周1周2周3 ,12时12分12秒执行
* 3.每月的哪几天执行 例:12 12 12 1,21,13 * ?表示每月的1号21号13号 12时12分12秒执行
* @author
* @date
*
*/
/**
*
*方法摘要：构建Cron表达式
*@param taskScheduleModel
*@return String
*/
public static String createCronExpression(TaskScheduleModel taskScheduleModel){
StringBuffer cronExp = new StringBuffer("");
if(null == taskScheduleModel.getJobType()) {
System.out.println("执行周期未配置" );//执行周期未配置
}
if (null != taskScheduleModel.getSecond()
&& null != taskScheduleModel.getMinute()
&& null != taskScheduleModel.getHour()) {
//秒
cronExp.append(taskScheduleModel.getSecond()).append(" ");
//分
cronExp.append(taskScheduleModel.getMinute()).append(" ");
//小时
cronExp.append(taskScheduleModel.getHour()).append(" ");
//每天
if(taskScheduleModel.getJobType().intValue() == 1){
//12 12 12 1/2 * ? *
//12 12 12 * * ?
if(taskScheduleModel.getBeApart()!=null){
cronExp.append("1");//日
cronExp.append("/");
cronExp.append(taskScheduleModel.getBeApart()+1);//月
cronExp.append(" ");
cronExp.append("* ");
cronExp.append("? ");//周
cronExp.append("*");
}else {
cronExp.append("* ");//日
cronExp.append("* ");//月
cronExp.append("?");//周
}
}
//按每周
else if(taskScheduleModel.getJobType().intValue() == 3){
//一个月中第几天
cronExp.append("? ");
//月份
cronExp.append("* ");
//周
Integer[] weeks = taskScheduleModel.getDayOfWeeks();
for(int i = 0; i < weeks.length; i++){
if(i == 0){
cronExp.append(weeks[i]);
} else{
cronExp.append(",").append(weeks[i]);
}
}
}
//按每月
else if(taskScheduleModel.getJobType().intValue() == 2){
//一个月中的哪几天
Integer[] days = taskScheduleModel.getDayOfMonths();
for(int i = 0; i < days.length; i++){
if(i == 0){
if(days[i]==32){
//本月最后一天
String endMouthCron="0 0 0 L * ?";
return endMouthCron;
}else {
cronExp.append(days[i]);
}
} else{
cronExp.append(",").append(days[i]);
}
}
//月份
cronExp.append(" * ");
//周
cronExp.append("?");
}
else if(taskScheduleModel.getJobType().intValue() == 0){
cronExp.append("* ");//日
cronExp.append("* ");//月
cronExp.append("?");//周
}
}
else {
System.out.println("时或分或秒参数未配置" );//时或分或秒参数未配置
}
return cronExp.toString();
}
/**
*
*方法摘要：生成计划的详细描述
*@param taskScheduleModel
*@return String
*/
public static String createDescription(TaskScheduleModel taskScheduleModel){
StringBuffer description = new StringBuffer("");
//计划执行开始时间
// Date startTime = taskScheduleModel.getScheduleStartTime();
if (null != taskScheduleModel.getSecond()
&& null != taskScheduleModel.getMinute()
&& null != taskScheduleModel.getHour()) {
//按每天
if(taskScheduleModel.getJobType().intValue() == 1){
description.append("每天");
description.append(taskScheduleModel.getHour()).append("时");
description.append(taskScheduleModel.getMinute()).append("分");
description.append(taskScheduleModel.getSecond()).append("秒");
description.append("执行");
}
//按每周
else if(taskScheduleModel.getJobType().intValue() == 3){
if(taskScheduleModel.getDayOfWeeks() != null && taskScheduleModel.getDayOfWeeks().length > 0) {
String days = "";
for(int i : taskScheduleModel.getDayOfWeeks()) {
days += "周" + i;
}
description.append("每周的").append(days).append(" ");
}
if (null != taskScheduleModel.getSecond()
&& null != taskScheduleModel.getMinute()
&& null != taskScheduleModel.getHour()) {
description.append(",");
description.append(taskScheduleModel.getHour()).append("时");
description.append(taskScheduleModel.getMinute()).append("分");
description.append(taskScheduleModel.getSecond()).append("秒");
}
description.append("执行");
}
//按每月
else if(taskScheduleModel.getJobType().intValue() == 2){
//选择月份
if(taskScheduleModel.getDayOfMonths() != null && taskScheduleModel.getDayOfMonths().length > 0) {
String days = "";
for(int i : taskScheduleModel.getDayOfMonths()) {
days += i + "号";
}
description.append("每月的").append(days).append(" ");
}
description.append(taskScheduleModel.getHour()).append("时");
description.append(taskScheduleModel.getMinute()).append("分");
description.append(taskScheduleModel.getSecond()).append("秒");
description.append("执行");
}
}
return description.toString();
}
/**
* @description: 构建Cron表达式
* @param rate cycle
* @return String
* @author panlupeng
* @date 2021/9/27 15:55
*/
public static String createLoopCronExpression(int rate, int cycle) {
String cron = "";
switch (rate) {
case 0:// 每cycle秒执行一次
cron = "0/" + cycle + " * * * * ?";
break;
case 1:// 每cycle分钟执行一次
cron = "0 0/" + cycle + " * * * ?";
break;
case 2:// 每cycle小时执行一次
cron = "0 0 0/" + cycle + " * * ?";
break;
case 3:// 每cycle天的0点执行一次
cron = "0 0 0 1/" + cycle + " * ?";
break;
case 4:// 每cycle月的1号0点执行一次
cron = "0 0 0 1 1/" + cycle + " ? ";
break;
case 5:// 每天cycle点执行一次
cron = "0 0 " + cycle+ " * * ?";
break;
default:// 默认每cycle秒执行一次
cron = "0/1 * * * * ?";
break;
}
return cron;
}
public static void main(String[] args) {
//执行时间：每天的12时12分12秒 start
TaskScheduleModel taskScheduleModel = new TaskScheduleModel();
taskScheduleModel.setJobType(1);//按每天
Integer hour = 12; //时
Integer minute = 12; //分
Integer second = 12; //秒
taskScheduleModel.setHour(hour);
taskScheduleModel.setMinute(minute);
taskScheduleModel.setSecond(second);
//每隔几天执行
taskScheduleModel.setBeApart(1);
String cropExp = createCronExpression(taskScheduleModel);
System.out.println(cropExp + ":" + createDescription(taskScheduleModel));
//执行时间：每天的12时12分12秒 end
taskScheduleModel.setJobType(3);//每周的哪几天执行
Integer[] dayOfWeeks = new Integer[3];
dayOfWeeks[0] = 1;
dayOfWeeks[1] = 2;
dayOfWeeks[2] = 3;
taskScheduleModel.setDayOfWeeks(dayOfWeeks);
cropExp = createCronExpression(taskScheduleModel);
System.out.println(cropExp + ":" + createDescription(taskScheduleModel));
taskScheduleModel.setJobType(2);//每月的哪几天执行
Integer[] dayOfMonths = new Integer[3];
dayOfMonths[0] = 1;
dayOfMonths[1] = 21;
dayOfMonths[2] = 13;
taskScheduleModel.setDayOfMonths(dayOfMonths);
cropExp = createCronExpression(taskScheduleModel);
System.out.println(cropExp + ":" + createDescription(taskScheduleModel));
taskScheduleModel.setJobType(0);//每天的几点几分几秒开始
cropExp = createCronExpression(taskScheduleModel);
System.out.println(cropExp);
}
测试一下:
