Unexpected exception during bean creation; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder '' in value "${}" 에러

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'messageSource' defined in class path resource [com/spring/practice/api/config/MessageConfiguration.class]: Unexpected exception during bean creation; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'spring.message.basename' in value "${spring.message.basename}"
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:537) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:213) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.context.support.AbstractApplicationContext.initMessageSource(AbstractApplicationContext.java:772) ~[spring-context-5.3.9.jar:5.3.9]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:571) ~[spring-context-5.3.9.jar:5.3.9]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.3.jar:2.5.3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-2.5.3.jar:2.5.3]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-2.5.3.jar:2.5.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) ~[spring-boot-2.5.3.jar:2.5.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-2.5.3.jar:2.5.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) ~[spring-boot-2.5.3.jar:2.5.3]
	at com.spring.practice.api.ApiApplication.main(ApiApplication.java:10) ~[classes/:na]
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'spring.message.basename' in value "${spring.message.basename}"
	at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:180) ~[spring-core-5.3.9.jar:5.3.9]
	at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:126) ~[spring-core-5.3.9.jar:5.3.9]
	at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:239) ~[spring-core-5.3.9.jar:5.3.9]
	at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:210) ~[spring-core-5.3.9.jar:5.3.9]
	at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties$0(PropertySourcesPlaceholderConfigurer.java:175) ~[spring-context-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:936) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1321) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1300) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:887) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:541) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1334) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.3.9.jar:5.3.9]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:564) ~[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]
	... 13 common frames omitted


Process finished with exit code 1

spring 에서 IllegalArgumentException 이 발생했다.

 

 

원인

application.yml 에는 messages 라고 적혀있지만 yml파일을 참조하는 Value에 message라고 적음

@Bean // yml 파일을 참조하는 MessageSource 선언
    public MessageSource messageSource(
          @Value("${spring.message.basename}") String basename,
          @Value("${spring.message.encoding}") String encoding
    ) {
        YamlMessageSource ms = new YamlMessageSource();
        ms.setBasename(basename);
        ms.setDefaultEncoding(encoding);
        ms.setAlwaysUseMessageFormat(true);
        ms.setUseCodeAsDefaultMessage(true);
        ms.setFallbackToSystemLocale(true);
        return ms;
    }

spring:
  port: 8080
  messages:
    basename: i18n/exception
    encoding: UTF-8

 

해결방법

yml을 바르게 참조할 수 있도록 경로를 올바르게 수정

@Value("${spring.messages.basename}") String basename,
@Value("${spring.messages.encoding}") String encoding