使用@PropertySource批注时未解析@Value。如何配置PropertySourcesPlaceHolderConfigurer？

Question

@Configuration
@PropertySource(name = "props", value = "classpath:/app-config.properties")
@ComponentScan("service")
public class AppConfig {

@Component 
public class SomeService {
    @Value("#{props['some.property']}") private String someProperty;

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'someService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.lang.String service.SomeService.someProperty; nested exception is org.springframework.beans.factory.BeanExpressionException: Expression parsing failed; nested exception is org.springframework.expression.spel.SpelEvaluationException: EL1008E:(pos 0): Field or property 'props' cannot be found on object of type 'org.springframework.beans.factory.config.BeanExpressionContext' 

这种方法适用于xml配置

<util:properties id="props" location="classpath:/app-config.properties" />

但我想使用java进行配置。

Answer 1

如果使用@PropertySource，则必须使用以下方法检索属性：

@Autowired
Environment env;
// ...
String subject = env.getProperty("mail.subject");

如果要使用@value（“${mail.subject}”）进行检索，则必须通过XML注册合适的占位符。

原因：https://jira.springsource.org/browse/spr-8539