Question

XML配置：

<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"
    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">


    <bean class="com.fossians.maven_courses.Say_Impl" id="id_Say_Impl" />
</beans>

Say_I

public interface Say_I
    {
        public void Say_I_m1();
    }

Say_Impl

public class Say_Impl implements Say_I
    {
        public void Say_I_m1()
            {
                System.out.println("inside : public void Say_I_m1() \n");
            }
    }

控制器：

public class Controller_Test implements SpringApplicationContextInterface
    {
        @Autowired
        private Say_Impl say_Impl;

        //Below line not assigning, need to reassign into method
        private Say_I say_I =  (Say_I) say_Impl;
//        private Say_I say_I =  (Say_I) applicationContext.getBean("id_Say_Impl");

        @RequestMapping(value = "/test10")
        public String Test1()
        {
            say_I = say_Impl;
            System.out.println("Say_Impl_auto : "+say_Impl);
            System.out.println("Say_I : "+say_I);
            say_I.Say_I_m1();
            return " request value = test10 ";
        }  
    }

public interface SpringApplicationContextInterface 
{
 ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beanConfig.xml");
}


@SpringBootApplication
@ImportResource("classpath:beanConfig.xml")
public class Courses  extends SpringBootServletInitializer
{
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) 
    {
        return application.sources(Courses.class);
    }

}

上面的代码是spring boot应用程序的一部分。

“Controller_Test”类中的这行代码：

 private Say_I say_I =  (Say_I) say_Impl;

未将Say_Impl对象“say_Impl”引用分配给其父对象say_I。但是，如果我再次将它分配给Test1（）方法，那么它正在工作。

但下面的代码行将say_Impl引用分配给say_I对象。

private Say_I say_I =  (Say_I) applicationContext.getBean("id_Say_Impl");

现在我的问题是，当我通过自动装配获取say_impl对象时为什么我需要将其重新分配给方法？有没有办法让它在没有重新分配的情况下工作？

当我通过应用程序上下文获取bean时，我不需要重新分配，为什么？

Answer 1

非常难看的代码，带有spring boot WTF的旧版xml？

试试这个

@Autowired
private Say_I say_I;

或更好：

@SpringBootApplication
public class Courses {

    public static void main(String[] args) {
        SpringApplication.run(Courses.class, args);
    }

    @RestController
    public class Controller_Test {

        @Autowired
        private Say_I say_I;

        @RequestMapping(value = "/test10")
        public String Test1() {
            System.out.println("Say_I : " + say_I);
            say_I.Say_I_m1();
            return " request value = test10 ";
        }
    }   

    @Component
    public class Say_I {    
        void Say_I_m1() {
            System.out.println("inside : public void Say_I_m1() \n");
        }
    }

}

无法在Spring Boot中将自动装配的子bean分配给父对象

1 个答案: