本文介绍通过java生成cron表达式，解析表达式，计算表达式执行日期
1. 生成表达式
public static String createCronExpression(CronModel cronModel){
StringBuilder cronExp = new StringBuilder();
if(null == cronModel.getJobType()) {
System.out.println("执行周期未配置" );//执行周期未配置
}
if (null != cronModel.getSecond()
&& null != cronModel.getMinute()
&& null != cronModel.getHour()) {
//秒
cronExp.append(cronModel.getSecond()).append(" ");
//分
cronExp.append(cronModel.getMinute()).append(" ");
//小时
cronExp.append(cronModel.getHour()).append(" ");
//每天
if(cronModel.getJobType().getValue() == 1){
//12 12 12 1/2 * ? *
//12 12 12 * * ?
if(cronModel.getBeApart()!=null){
cronExp.append("1");//日
cronExp.append("/");
cronExp.append(cronModel.getBeApart()+1);//月
cronExp.append(" ");
cronExp.append("* ");
cronExp.append("?");
}else {
cronExp.append("* ");//日
cronExp.append("* ");//月
cronExp.append("?");
}
}
//按每周
else if(cronModel.getJobType().getValue() == 3){
//一个月中第几天
cronExp.append("? ");
//月份
cronExp.append("* ");
//周
Integer[] weeks = cronModel.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(cronModel.getJobType().getValue()== 2){
//一个月中的哪几天
Integer[] days = cronModel.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("?");
}
//按每年
else if(cronModel.getJobType().getValue()== 4){
//一个年中的哪几天
Integer[] days = cronModel.getDayOfMonths();
if(ArrayUtil.isEmpty(days)){
cronExp.append("*");
}else{
for(int i = 0; i < days.length; i++){
if(i == 0){
cronExp.append(days[i]);
} else{
cronExp.append(",").append(days[i]);
}
}
}
//月份
Integer[] months = cronModel.getMonths();
if (ArrayUtil.isEmpty(months)) {
cronExp.append(" *");
}else{
for (int i = 0; i < months.length; i++){
Integer month = months[i];
if (month > 12){
throw new RuntimeException("月份数据异常: "+ Arrays.toString(months));
}
if(i == 0){
cronExp.append(" ").append(month);
}else{
cronExp.append(",").append(month);
}
}
}
cronExp.append(" ?");
}
else if(cronModel.getJobType().getValue() == 0){
cronExp.append("* ");//日
cronExp.append("* ");//月
cronExp.append("?");//周
}
}
return cronExp.toString();
}
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;
}
2. 解析表达式
/**
* 生成计划的详细描述
*
*@param cronModel
*@return String
*/
public static String createDescription(CronModel cronModel){
StringBuffer description = new StringBuffer("");
//计划执行开始时间
// Date startTime = cronModel.getScheduleStartTime();
if (null != cronModel.getSecond()
&& null != cronModel.getMinute()
&& null != cronModel.getHour()) {
//按每天
if(cronModel.getJobType().getValue() == 1){
Integer beApart = cronModel.getBeApart();
if(beApart !=null){
description.append("每间隔").append(beApart).append("天");
}else{
description.append("每天");
}
description.append(cronModel.getHour()).append("时");
description.append(cronModel.getMinute()).append("分");
description.append(cronModel.getSecond()).append("秒");
description.append("执行");
}
//按每周
else if(cronModel.getJobType().getValue() == 3){
if(cronModel.getDayOfWeeks() != null && cronModel.getDayOfWeeks().length > 0) {
String days = "";
for(int i : cronModel.getDayOfWeeks()) {
days += "周" + i;
}
description.append("每周的").append(days).append(" ");
}
if (null != cronModel.getSecond()
&& null != cronModel.getMinute()
&& null != cronModel.getHour()) {
description.append(",");
description.append(cronModel.getHour()).append("时");
description.append(cronModel.getMinute()).append("分");
description.append(cronModel.getSecond()).append("秒");
}
description.append("执行");
}
//按每月
else if(cronModel.getJobType().getValue() == 2){
//选择月份
if(cronModel.getDayOfMonths() != null && cronModel.getDayOfMonths().length > 0) {
String days = "";
for(int i : cronModel.getDayOfMonths()) {
days += i + "号";
}
description.append("每月的").append(days).append(" ");
}
description.append(cronModel.getHour()).append("时");
description.append(cronModel.getMinute()).append("分");
description.append(cronModel.getSecond()).append("秒");
description.append("执行");
}
}
return description.toString();
}
3. 计算表达式执行日期
需要引入quartz依赖
<dependency>
<groupId>quartz</groupId>
<artifactId>quartz</artifactId>
<version>1.5.2</version>
</dependency>
/**
* 计算表达式最近几次执行时间
* @param cronExpress 表达式
* @param num 次数
* @return 时间集合
*/
public static List<String> getCronNextTimes(String cronExpress,Integer num){
if(StrUtil.isEmpty(cronExpress)){
throw new RuntimeException("cron 表达式不能为空");
}
//判断cron表达式
if(!CronSequenceGenerator.isValidExpression(cronExpress)){
throw new RuntimeException("cron 表达式格式不正确,cron: "+cronExpress);
}
if(num == null || num == 0){
num = 1;
}
List<String> list = new ArrayList<>();
CronTrigger cronTrigger = new CronTrigger();
try {
cronTrigger.setCronExpression(cronExpress);
} catch (ParseException e) {
throw new RuntimeException("cron表达式不正确,cron: "+cronExpress);
}
List<Date> dates = TriggerUtils.computeFireTimes(cronTrigger, null, num);
String format = "yyyy-MM-dd HH:mm:ss";
for (Date date : dates) {
list.add(DateUtil.format(date,format));
}
return list;
}
4. 测试
public static void main(String[] args) {
CronModel cronModel = new CronModel();
cronModel.setJobType(JobEnum.DAY);//按每天
//每隔几天执行
cronModel.setBeApart(1);
String cropExp = createCronExpression(cronModel);
System.out.println(cropExp + ":" + createDescription(cronModel));
//执行时间：每天的12时12分12秒 end
System.out.println(getCronNextTimes(cropExp, 5));
cronModel.setJobType(JobEnum.WEEK);//每周的哪几天执行
Integer[] dayOfWeeks = new Integer[3];
dayOfWeeks[0] = 1;
dayOfWeeks[1] = 2;
dayOfWeeks[2] = 3;
cronModel.setDayOfWeeks(dayOfWeeks);
cronModel.setJobType(JobEnum.WEEK);
cropExp = createCronExpression(cronModel);
System.out.println(cropExp + ":" + createDescription(cronModel));
System.out.println(getCronNextTimes(cropExp, 5));
cronModel.setJobType(JobEnum.MONTH);//每月的哪几天执行
Integer[] dayOfMonths = new Integer[3];
dayOfMonths[0] = 1;
dayOfMonths[1] = 21;
dayOfMonths[2] = 13;
cronModel.setDayOfMonths(dayOfMonths);
cropExp = createCronExpression(cronModel);
System.out.println(cropExp + ":" + createDescription(cronModel));
System.out.println(getCronNextTimes(cropExp, 5));
cronModel.setJobType(JobEnum.EVERY);//每天的几点几分几秒开始
cropExp = createCronExpression(cronModel);
System.out.println(cropExp);
System.out.println(getCronNextTimes(cropExp, 5));
}
5. 完整代码
gitee地址:
https://gitee.com/zhenglm/tools.git
1
/**
* @author zlm
* @date 2023/8/3
*/
public enum JobEnum {
EVERY("每天",0),
DAY("日",1),
MONTH("月",2),
WEEK("周",3),
YEAR("年",4),
;
JobEnum(String name,Integer value) {
this.name = name;
this.value = value;
}
private final String name;
private final Integer value;
public Integer getValue() {
return value;
}
public String getName() {
return name;
}
}
public class CronModel {
Integer[] dayOfWeeks;
Integer[] dayOfMonths;
Integer[] months;
Integer second;
Integer minute;
Integer hour;
/**
* 类型
*/
JobEnum jobType;
/**
* 间隔
*/
Integer beApart;
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[] getMonths() {
return months;
}
public void setMonths(Integer[] months) {
this.months = months;
}
public Integer getSecond() {
return second == null ? 0 : second;
}
public void setSecond(Integer second) {
this.second = second;
}
public Integer getMinute() {
return minute == null ? 0 : minute;
}
public void setMinute(Integer minute) {
this.minute = minute;
}
public Integer getHour() {
return hour==null ? 0 : hour;
}
public void setHour(Integer hour) {
this.hour = hour;
}
public JobEnum getJobType() {
return jobType == null ? JobEnum.DAY : jobType;
}
public void setJobType(JobEnum jobType) {
this.jobType = jobType;
}
public Integer getBeApart() {
return beApart;
}
public void setBeApart(Integer beApart) {
this.beApart = beApart;
}
}
/**
* @author zlm
* @date 2023/8/3
*
* 字段 允许值 允许的特殊字符
* 秒 0-59 , – * /
* 分 0-59 , – * /
* 小时 0-23 , – * /
* 日期 1-31 , – * ? / L W C
* 月份 1-12 或者 JAN-DEC , – * /
* 星期 1-7 或者 SUN-SAT , – * ? / L C #
* 年（可选） 留空, 1970-2099 , – * /
*
* * 表示所有值；
* ? 表示未说明的值，即不关心它为何值；
* – 表示一个指定的范围；
* , 表示附加一个可能值；
* / 符号前表示开始时间，符号后表示每次递增的值；
* L("last") ("last") "L" 用在day-of-month字段意思是 "这个月最后一天"；用在 day-of-week字段, 它简单意思是 "7" or "SAT"。 如果在day-of-week字段里和数字联合使用，它的意思就是 "这个月的最后一个星期几" – 例如： "6L" means "这个月的最后一个星期五". 当我们用“L”时，不指明一个列表值或者范围是很重要的，不然的话，我们会得到一些意想不到的结果。
* W("weekday") 只能用在day-of-month字段。用来描叙最接近指定天的工作日（周一到周五）。例如：在day-of-month字段用“15W”指“最接近这个 月第15天的工作日”，即如果这个月第15天是周六，那么触发器将会在这个月第14天即周五触发；如果这个月第15天是周日，那么触发器将会在这个月第 16天即周一触发；如果这个月第15天是周二，那么就在触发器这天触发。注意一点：这个用法只会在当前月计算值，不会越过当前月。“W”字符仅能在 day-of-month指明一天，不能是一个范围或列表。也可以用“LW”来指定这个月的最后一个工作日。
* # 只能用在day-of-week字段。用来指定这个月的第几个周几。例：在day-of-week字段用"6#3"指这个月第3个周五（6指周五，3指第3个）。如果指定的日期不存在，触发器就不会触发。
* C 指和calendar联系后计算过的值。例：在day-of-month 字段用“5C”指在这个月第5天或之后包括calendar的第一天；在day-of-week字段用“1C”指在这周日或之后包括calendar的第一天。
*
*
*/
public class CronUtil {
/**
* 计算表达式最近几次执行时间
* @param cronExpress 表达式
* @param num 次数
* @return 时间集合
*/
public static List<String> getCronNextTimes(String cronExpress,Integer num){
if(StrUtil.isEmpty(cronExpress)){
throw new RuntimeException("cron 表达式不能为空");
}
//判断cron表达式
if(!CronSequenceGenerator.isValidExpression(cronExpress)){
throw new RuntimeException("cron 表达式格式不正确,cron: "+cronExpress);
}
if(num == null || num == 0){
num = 1;
}
List<String> list = new ArrayList<>();
CronTrigger cronTrigger = new CronTrigger();
try {
cronTrigger.setCronExpression(cronExpress);
} catch (ParseException e) {
throw new RuntimeException("cron表达式不正确,cron: "+cronExpress);
}
List<Date> dates = TriggerUtils.computeFireTimes(cronTrigger, null, num);
String format = "yyyy-MM-dd HH:mm:ss";
for (Date date : dates) {
list.add(DateUtil.format(date,format));
}
return list;
}
/**
* 构建Cron表达式
* 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
*
*
*/
public static String createCronExpression(CronModel cronModel){
StringBuilder cronExp = new StringBuilder();
if(null == cronModel.getJobType()) {
System.out.println("执行周期未配置" );//执行周期未配置
}
if (null != cronModel.getSecond()
&& null != cronModel.getMinute()
&& null != cronModel.getHour()) {
//秒
cronExp.append(cronModel.getSecond()).append(" ");
//分
cronExp.append(cronModel.getMinute()).append(" ");
//小时
cronExp.append(cronModel.getHour()).append(" ");
//每天
if(cronModel.getJobType().getValue() == 1){
//12 12 12 1/2 * ? *
//12 12 12 * * ?
if(cronModel.getBeApart()!=null){
cronExp.append("1");//日
cronExp.append("/");
cronExp.append(cronModel.getBeApart()+1);//月
cronExp.append(" ");
cronExp.append("* ");
cronExp.append("?");
}else {
cronExp.append("* ");//日
cronExp.append("* ");//月
cronExp.append("?");//周
}
}
//按每周
else if(cronModel.getJobType().getValue() == 3){
//一个月中第几天
cronExp.append("? ");
//月份
cronExp.append("* ");
//周
Integer[] weeks = cronModel.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(cronModel.getJobType().getValue()== 2){
//一个月中的哪几天
Integer[] days = cronModel.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("?");
}
//按每年
else if(cronModel.getJobType().getValue()== 4){
//一个年中的哪几天
Integer[] days = cronModel.getDayOfMonths();
if(ArrayUtil.isEmpty(days)){
cronExp.append("*");
}else{
for(int i = 0; i < days.length; i++){
if(i == 0){
cronExp.append(days[i]);
} else{
cronExp.append(",").append(days[i]);
}
}
}
//月份
Integer[] months = cronModel.getMonths();
if (ArrayUtil.isEmpty(months)) {
cronExp.append(" *");
}else{
for (int i = 0; i < months.length; i++){
Integer month = months[i];
if (month > 12){
throw new RuntimeException("月份数据异常: "+ Arrays.toString(months));
}
if(i == 0){
cronExp.append(" ").append(month);
}else{
cronExp.append(",").append(month);
}
}
}
cronExp.append(" ?");
}
else if(cronModel.getJobType().getValue() == 0){
cronExp.append("* ");//日
cronExp.append("* ");//月
cronExp.append("?");//周
}
}
return cronExp.toString();
}
/**
* 生成计划的详细描述
*
*@param cronModel
*@return String
*/
public static String createDescription(CronModel cronModel){
StringBuffer description = new StringBuffer("");
//计划执行开始时间
// Date startTime = cronModel.getScheduleStartTime();
if (null != cronModel.getSecond()
&& null != cronModel.getMinute()
&& null != cronModel.getHour()) {
//按每天
if(cronModel.getJobType().getValue() == 1){
Integer beApart = cronModel.getBeApart();
if(beApart !=null){
description.append("每间隔").append(beApart).append("天");
}else{
description.append("每天");
}
description.append(cronModel.getHour()).append("时");
description.append(cronModel.getMinute()).append("分");
description.append(cronModel.getSecond()).append("秒");
description.append("执行");
}
//按每周
else if(cronModel.getJobType().getValue() == 3){
if(cronModel.getDayOfWeeks() != null && cronModel.getDayOfWeeks().length > 0) {
String days = "";
for(int i : cronModel.getDayOfWeeks()) {
days += "周" + i;
}
description.append("每周的").append(days).append(" ");
}
if (null != cronModel.getSecond()
&& null != cronModel.getMinute()
&& null != cronModel.getHour()) {
description.append(",");
description.append(cronModel.getHour()).append("时");
description.append(cronModel.getMinute()).append("分");
description.append(cronModel.getSecond()).append("秒");
}
description.append("执行");
}
//按每月
else if(cronModel.getJobType().getValue() == 2){
//选择月份
if(cronModel.getDayOfMonths() != null && cronModel.getDayOfMonths().length > 0) {
String days = "";
for(int i : cronModel.getDayOfMonths()) {
days += i + "号";
}
description.append("每月的").append(days).append(" ");
}
description.append(cronModel.getHour()).append("时");
description.append(cronModel.getMinute()).append("分");
description.append(cronModel.getSecond()).append("秒");
description.append("执行");
}
}
return description.toString();
}
/**
* 构建Cron表达式
* @param rate 第几位
* @param cycle 数值
* @return
*/
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) {
CronModel cronModel = new CronModel();
cronModel.setJobType(JobEnum.DAY);//按每天
//每隔几天执行
cronModel.setBeApart(1);
String cropExp = createCronExpression(cronModel);
System.out.println(cropExp + ":" + createDescription(cronModel));
//执行时间：每天的12时12分12秒 end
System.out.println(getCronNextTimes(cropExp, 5));
cronModel.setJobType(JobEnum.WEEK);//每周的哪几天执行
Integer[] dayOfWeeks = new Integer[3];
dayOfWeeks[0] = 1;
dayOfWeeks[1] = 2;
dayOfWeeks[2] = 3;
cronModel.setDayOfWeeks(dayOfWeeks);
cronModel.setJobType(JobEnum.WEEK);
cropExp = createCronExpression(cronModel);
System.out.println(cropExp + ":" + createDescription(cronModel));
System.out.println(getCronNextTimes(cropExp, 5));
cronModel.setJobType(JobEnum.MONTH);//每月的哪几天执行
Integer[] dayOfMonths = new Integer[3];
dayOfMonths[0] = 1;
dayOfMonths[1] = 21;
dayOfMonths[2] = 13;
cronModel.setDayOfMonths(dayOfMonths);
cropExp = createCronExpression(cronModel);
System.out.println(cropExp + ":" + createDescription(cronModel));
System.out.println(getCronNextTimes(cropExp, 5));
cronModel.setJobType(JobEnum.EVERY);//每天的几点几分几秒开始
cropExp = createCronExpression(cronModel);
System.out.println(cropExp);
System.out.println(getCronNextTimes(cropExp, 5));
}
}
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版权声明：本文为CSDN博主「*郑*」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/weixin_42202992/article/details/132085828