如何正确地将@ducedured（）注释CRON表达式外化到我的application.properties文件中？它无法解析占位符

Question

@Scheduled(cron = "0 42 13 * * *")
public void runUpdateNotaryDistrictsJob() {
    LOGGER.info("SCHEDULED run of updateNotaryDistrictsJob STARTED");
    Map<String, JobParameter> confMap = new HashMap<>();
    confMap.put("time", new JobParameter(System.currentTimeMillis()));
    JobParameters jobParameters = new JobParameters(confMap);
    try {
        jobLauncher.run(updateNotaryDistrictsJob, jobParameters);
    }catch (Exception ex){
        LOGGER.error(ex.getMessage());
    }

}

然后，我试图将这个表达式外部化为一个占位符，它的值被定义到application.properties文件中。

因此，我在application.properties文件中定义了以下内容：

cron.expresion.runUpdateNotaryDistrictJob='0 32 11 * * *'

然后我以这样的方式更改了前面的@Schedured方法注释：

@Scheduled(cron = "${cron.expresion.runUpdateNotaryDistrictJob=}")
public void runUpdateNotaryDistrictsJob() {
    LOGGER.info("SCHEDULED run of updateNotaryDistrictsJob STARTED");
    Map<String, JobParameter> confMap = new HashMap<>();
    confMap.put("time", new JobParameter(System.currentTimeMillis()));
    JobParameters jobParameters = new JobParameters(confMap);
    try {
        jobLauncher.run(updateNotaryDistrictsJob, jobParameters);
    }catch (Exception ex){
        LOGGER.error(ex.getMessage());
    }

}

现在的问题是，在运行这个Spring Boot应用程序时，我获得了以下异常：

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-10-26 11:30:43.556 ERROR 6117 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'springBatchExampleJobLauncher' defined in file [/home/andrea/git/notartel-api-batch/target/classes/com/notariato/updateInfo/SpringBatchExampleJobLauncher.class]: Initialization of bean failed; nested exception is java.lang.IllegalStateException: Encountered invalid @Scheduled method 'runUpdateNotaryDistrictsJob': Could not resolve placeholder 'cron.expresion.runUpdateNotaryDistrictJob=' in value "${cron.expresion.runUpdateNotaryDistrictJob=}"
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:610) ~[spring-beans-5.3.9.jar:5.3.9]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.9.jar:5.3.9]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.9.jar:5.3.9]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.9.jar:5.3.9]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.9.jar:5.3.9]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.9.jar:5.3.9]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944) ~[spring-beans-5.3.9.jar:5.3.9]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.9.jar:5.3.9]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.9.jar:5.3.9]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.3.jar:2.5.3]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-2.5.3.jar:2.5.3]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-2.5.3.jar:2.5.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) ~[spring-boot-2.5.3.jar:2.5.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-2.5.3.jar:2.5.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) ~[spring-boot-2.5.3.jar:2.5.3]
    at com.notariato.updateInfo.UpdateInfoBatchApplication.main(UpdateInfoBatchApplication.java:42) ~[classes/:na]
Caused by: java.lang.IllegalStateException: Encountered invalid @Scheduled method 'runUpdateNotaryDistrictsJob': Could not resolve placeholder 'cron.expresion.runUpdateNotaryDistrictJob=' in value "${cron.expresion.runUpdateNotaryDistrictJob=}"
    at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.processScheduled(ScheduledAnnotationBeanPostProcessor.java:511) ~[spring-context-5.3.9.jar:5.3.9]
    at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.lambda$null$1(ScheduledAnnotationBeanPostProcessor.java:374) ~[spring-context-5.3.9.jar:5.3.9]
    at java.base/java.lang.Iterable.forEach(Iterable.java:75) ~[na:na]
    at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.lambda$postProcessAfterInitialization$2(ScheduledAnnotationBeanPostProcessor.java:374) ~[spring-context-5.3.9.jar:5.3.9]
    at java.base/java.util.LinkedHashMap.forEach(LinkedHashMap.java:684) ~[na:na]
    at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.postProcessAfterInitialization(ScheduledAnnotationBeanPostProcessor.java:373) ~[spring-context-5.3.9.jar:5.3.9]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:437) ~[spring-beans-5.3.9.jar:5.3.9]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1790) ~[spring-beans-5.3.9.jar:5.3.9]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:602) ~[spring-beans-5.3.9.jar:5.3.9]
    ... 15 common frames omitted

Answer 1

@Scheduled(cron = "${cron.expresion.runUpdateNotaryDistrictJob}")

cron.expresion.runUpdateNotaryDistrictJob = 0 32 11 * * *