0006SpringBoot中@Configuration與@Bean聯合使用

需求：將某個普通類做為組件注冊到容器中，可通過如下辦法

1、定義HelloService類

package springboot_test.springboot_test.service;

public class HelloService {
}

2、定義配置類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 {
　　//方法名稱即為組件的id值
    @Bean
    public HelloService helloService(){
        return new HelloService();
    }
}

3、在原有測試類PersonTest.java中增加testHelloService()測試方法

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;

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


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