Cannot get value from application.yml in ApplicationRunner - spring-boot

Question

I've added my tiny initialization class in the same package with Spring Boot application (the main) class. (I want to perform some database initialization after all tables are created by Hibernate's spring.jpa.hibernate.ddl-auto property.) But the initialization class is not get populated with properties from application.yml.
Initialization class:
#Component
public class LocalInitializer implements ApplicationRunner {
#Value("${local.initialize}")
private String[] localInitialize;
#Override
public void run(ApplicationArguments args) throws Exception {
System.out.println(Arrays.toString(localInitialize));
}
}
application.yml:
local.initialize:
- test-string1
- test-string2
error:
...
Hibernate: drop table if exists t_worker cascade
Hibernate: drop sequence if exists hibernate_sequence
2019-05-22 17:06:45.530 INFO 16680 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown initiated...
2019-05-22 17:06:45.541 INFO 16680 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown completed.
2019-05-22 17:06:45.542 INFO 16680 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2019-05-22 17:06:45.579 INFO 16680 --- [ main] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-05-22 17:06:45.600 ERROR 16680 --- [ main] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'localInitializer': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'local.initialize' in value "${local.initialize}"
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:376) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1336) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:572) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:495) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:759) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:548) ~[spring-context-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:386) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1242) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1230) [spring-boot-2.0.6.RELEASE.jar:2.0.6.RELEASE]
at ua.aval.cards.dictionary.CardsDictionaryApp.main(CardsDictionaryApp.java:17) [classes/:na]
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'local.initialize' in value "${local.initialize}"
at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:172) ~[spring-core-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) ~[spring-core-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:237) ~[spring-core-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:211) ~[spring-core-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties$0(PropertySourcesPlaceholderConfigurer.java:175) ~[spring-context-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:839) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1083) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1062) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:581) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:370) ~[spring-beans-5.0.10.RELEASE.jar:5.0.10.RELEASE]
... 17 common frames omitted
Disconnected from the target VM, address: '127.0.0.1:55405', transport: 'socket'
Process finished with exit code 1

Answer 1

local.initialize:
test-string1,
test-string2
should work. note: use a ',' and leave out the '-' char
Remark:
When using a ConfigurationProperties Component like
#Component
#ConfigurationProperties(prefix = "myprops")
public class MyProperties {
private String[] initialize;
public String[] getInitialize() {
return initialize;
}
public void setInitialize(String[] initialize) {
this.initialize = initialize;
}
}
then this works
#Component
public class LocalInitializer implements CommandLineRunner{
private final MyProperties myprops;
#Value("${local.initialize:failed}")
private String[] localInitialize;
public LocalInitializer(MyProperties myprops) {
this.myprops = myprops;
}
#Override
public void run(String... args) throws Exception {
System.out.println(Arrays.toString(localInitialize));
System.out.println(Arrays.toString(myprops.getInitialize()));
}
}
in combination with application.yaml
local.initialize:
test-string1,
test-string2
myprops:
initialize:
- this is
- a bit
- strange
prints out
[test-string1, test-string2]
[this is, a bit, strange]