Java中Cron表达式的生成解析和计算的工具类

Java中Cron表达式的生成解析和计算的工具类

• • 1. 生成表达式
  • 2. 解析表达式
  • 3. 计算表达式执行日期
  • 4. 测试
  • 5. 完整代码

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 * *@paramcronModel *@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 endSystem.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

/** * @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 * *@paramcronModel *@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 endSystem.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));}}