使用配置类时的Spring自动装配

时间:2017-02-16 18:19:10

标签: java spring autowired

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>

我使用像这样的构造函数自动装配

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();
       }
    }

自动装配工作正常。

现在我想将我的bean移动到Configuation类。 但是,如何移动代码以便自动装配起作用?

我试过这样,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;               
    }
}

1 个答案:

答案 0 :(得分:5)

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

这应该这样做:

@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: