0006SpringBoot中@Configuration与@Bean联合使用

需求：将某个普通类做为组件注册到容器中，可通过如下办法

1、定义HelloService类

package springboot_test.springboot_test.service;

public class HelloService {
}

2、定义配置类MyConfig.java

package springboot_test.springboot_test.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springboot_test.springboot_test.service.HelloService;

@Configuration
public class MyConfig {
　　//方法名称即为组件的id值
    @Bean
    public HelloService helloService(){
        return new HelloService();
    }
}

3、在原有测试类PersonTest.java中增加testHelloService()测试方法

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationContext;
import org.springframework.test.context.junit4.SpringRunner;
import springboot_test.springboot_test.SpringbootTestApplication;
import springboot_test.springboot_test.bean.Person;

@SpringBootTest(classes = SpringbootTestApplication.class)
@RunWith(SpringRunner.class)
public class PersonTest {
    @Autowired
    private Person person;

    @Autowired
    private ApplicationContext ac;

    //在通过@Configuration和@Bean定义MyConfig.java之前，打印值为false，即容器中不存在helloService组件
　　//在配置之后，打印值为true
　　@Test
    public void testHelloService(){
        boolean flag =ac.containsBean("helloService");
        System.out.println(flag);
    }

    @Test
    public void getPerson(){
        System.out.println(person);
    }
}