使用@PropertySource注释时@Value未解析.如何配置PropertySourcesPlaceholderConfigurer？

Question

我有以下配置类:

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

我有财产服务:

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

当我想要测试AppConfig配置类时,我收到错误

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' 

该问题记录在SPR-8539中

但无论如何我无法弄清楚如何配置PropertySourcesPlaceholderConfigurer 以使其工作.

编辑1

这种方法适用于xml配置

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

但我想用java进行配置.

Answer 1

正如@cwash所说;

@Configuration
@PropertySource("classpath:/test-config.properties")
public class TestConfig {

     @Value("${name}")
     public String name;


     //You need this
     @Bean
     public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
     }

}

Answer 2

如果使用@PropertySource,则必须使用以下内容检索属性:

@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prop占位符.

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

Answer 3

我发现原因@value不适合我,@value需要PropertySourcesPlaceholderConfigurer而不是一个PropertyPlaceholderConfigurer.我做了相同的更改,它对我有用,我使用的是Spring 4.0.3版本.我在配置文件中使用下面的代码配置了它.

@Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
   return new PropertySourcesPlaceholderConfigurer();
}

Answer 4

你的@Configuration类上是否需要一个方法来返回PropertySourcesPlaceholderConfigurer,带注释的@Bean并且是静态的,用Spring注册任何@PropertySource？

http://www.baeldung.com/2012/02/06/properties-with-spring/#java

https://jira.springsource.org/browse/SPR-8539

Answer 5

我遇到了同样的问题.@PropertySource打得不好@Value.一个快速的解决方法是使用XML配置,您可以@ImportResource像往常一样从Spring Java Configuration中引用它,并且XML配置文件将包含一个条目:( <context:property-placeholder />当然还有所需的命名空间仪式).没有任何其他更改@Value将在您的@Configurationpojo中注入属性.

Answer 6

这也可以用java这种方式配置

@Bean
public static PropertySourcesPlaceholderConfigurer properties() {
    PropertySourcesPlaceholderConfigurer configurer = new PropertySourcesPlaceholderConfigurer();
    configurer.setIgnoreUnresolvablePlaceholders(true);
    configurer.setIgnoreResourceNotFound(true);
    return configurer;
}