在spring中实例化bean无效

在做Struts2和Spring整合时遇到Spring实例化无效的情况，Action中代码如下：

public class UserAction extends ActionSupport {
@Resource
private UserService userService;

public String execute(){
//userService.saveUser(new Object());
System.out.println(userService);
System.out.println("struts2spring整合成功");
return "success";

}
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"> 
<!-- 自动扫描与装配bean -->
<context:component-scan base-package="com.bjwl"></context:component-scan>

</beans>