java - 使用配置类时 Spring Autowiring

Question

我有一个 xml bean 文件

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.0.xsd">
   <context:annotation-config/>
   <bean id="helloWorld" class="com.a.b.HelloWorld"> 
         <property name="attr1" value="Attr1 from XML"></property>
   </bean>
    <bean id="helloWorld2" class="com.a.b.HelloWorld2">
        <property name="attr2" value="Attr2 from XML"></property>
    </bean>
</beans>

我已经使用了这样的构造函数 Autowiring

public class HelloWorld2{
       private String attr2;
       public void setAttr2(String message){
          this.attr2  = message;
       }

       public void getAttr2(){
          System.out.println("getAttr2 == " + attr2);
       }


    }

public class HelloWorld{
       private String attr1;
       private HelloWorld2 helloWorld2;    
       public HelloWorld(){

       }
       @Autowired
       public HelloWorld(HelloWorld2 helloWorld2){
           System.out.println("hhh");
           this.helloWorld2 = helloWorld2;
       }


    public void setAttr1(String message){
          this.attr1  = message;
       }

       public void getAttr1(){
          System.out.println("getAttr1 == " + attr1);
       }
       public void getH(){
           helloWorld2.getAttr2();
       }
    }

Autowiring 工作正常。

现在我想将我的 bean 移至配置类。但是如何移动代码以便 Autowiring 工作呢？

我已经尝试过这样的方法，但它不起作用

@Configuration
public class Config {
    @Bean
    public HelloWorld helloWorld(){
        HelloWorld a = new HelloWorld();
        a.setAttr1("Demo Attr1");
        return a;

    }

    @Bean
    public HelloWorld2 helloWorld2(){
        HelloWorld2 a = new HelloWorld2();
        a.setAttr2("Demo Attr2");
        return a;               
    }
}

Answer 1

我认为您想要实现的是将 HelloWorld2 实例注入(inject)到创建 HelloWorld @Bean 的方法中？

这应该可以做到:

@Configuration
public class Config {
    @Bean
    public HelloWorld helloWorld(HelloWorld2 helloWorld2){
        HelloWorld a = new HelloWorld(helloWorld2);
        a.setAttr1("Demo Attr1");
        return a;

    }

    @Bean
    public HelloWorld2 helloWorld2(){
        HelloWorld2 a = new HelloWorld2();
        a.setAttr2("Demo Attr2");
        return a;               
    }
}

这可能是这些问题的重复:

• Understanding Spring Autowired usage
• Converting Spring XML file to Spring configuration class