SpringBoot自动装配基于此注解

1.创建配置类，代替xml文件

@Configuration  //作为配置类 代替xml配置文件
@ComponentScan(basePackages = {"com.spring5"})  //包扫描
public class SpringConfig {
}

2.junit测试类

    @Test
    public void springConfig(){

        ApplicationContext context = new AnnotationConfigApplicationContext(SpringConfig.class);

        UserService userService = context.getBean("userService", UserService.class);
        System.out.println(userService);
        userService.add();
    }