Spring 3.0.5不会评估属性的@Value注释 [英] Spring 3.0.5 doesn't evaluate @Value annotation from properties

问题描述

尝试将属性自动连接到 Spring 3.0.5.RELEASE 中的bean，我使用：

• config.properties ：

    username = myusername 
    




• main-components.xml ：

   < context：property-placeholder location =classpath：config.properties/> 
    




• MyClass：
  
  <$ p $ @Service
public class MyClass {

@Value（$ {username}）
private String username;
...
}


因此，用户名被设置为 $ {username}，所以表达式不会被解析。我对这个类的其他自动连线依赖性得到了设置，并且Spring不会抛出任何异常。我也尝试添加 @Autowired 但它没有帮助。

如果我将属性解析为单独的bean然后使用 @Autowired + @Qualifier ，它可以工作：

 < bean id =usernameclass =java.lang.String> 
< constructor-arg value =$ {username}/> 
< / bean> 
  

如何使用 @Value ？也许我需要包含一些我没有的Spring依赖项？谢谢

解决方案

找到问题所在。复制/粘贴评论：

您确定您的< context：property-placeholder> 应用程序上下文作为你的MyClass bean（不在父上下文中）？ - axtavt

你说得对。我从 ContextLoaderListener 定义的上下文中将< context：property-placeholder> 移到了servlet上下文中。现在我的值被解析。非常感谢！ - alex

Trying to auto-wire properties to a bean in Spring 3.0.5.RELEASE, I'm using:

• config.properties:

  username=myusername
  

• main-components.xml:

  <context:property-placeholder location="classpath:config.properties" />
  

• MyClass:

  @Service
  public class MyClass {
  
      @Value("${username}")
      private String username;
      ...
  }
  

As a result, username gets set to literally "${username}", so the expression doesn't get parsed. My other auto-wired dependencies on this class get set, and Spring doesn't throw any exception. I also tried to add @Autowired but it didn't help.

If I parse properties to a separate bean and then use @Autowired + @Qualifier, it works:

<bean id="username" class="java.lang.String">
    <constructor-arg value="${username}"/>
</bean>

Any ideas how to use just @Value? Maybe I need to include some Spring dependency that I haven't? Thank you

解决方案

Found what the issue was. Copy/paste from comments:

Are you sure you have <context:property-placeholder> in the same application context as your MyClass bean (not in the parent context)? – axtavt

You're right. I moved <context:property-placeholder> from the context defined by the ContextLoaderListener to the servlet context. Now my values get parsed. Thanks a lot! - alex

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