在spring中实例化bean无效的问题

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>

public abstract class TestBean {
    public String str;
    
    public TestBean(){
        this.str = initStr();
    }
    
    protected abstract String initStr();
}
public class TestSon extends TestBean {
    @Resource
    public String str;
    @Override
    protected String initStr() {
        return this.str;
    }
}

public class TestSon extends TestBean implements InitializingBean
{
    @Resource
    public String str;
    @Override
    protected String initStr() {
        return this.str;
    }
    @Override
    public void afterPropertiesSet() throws Exception {
        super.str = this.str;
    }
}