[Spring] Spring @Component뜻과 사용법

@Component
@Component 어노테이션을 이용하면 Bean Configuration 파일에 Bean을 따로 등록하지 않아도 사용할 수 있다.

빈 등록자체를 빈 클래스 자체에다가 할 수 있다는 의미이다.

 

 

ApplicationUser

//긁지않은 개발자
@AllArgsConstructor
@NoArgsConstructor
@Data
@Component("applicationUser")

public class ApplicationUser {
	 
    private String name="최고관리자";
 

}

Application

 

//긁지않은 개발자
@AllArgsConstructor
@NoArgsConstructor
@Data
@Component("application")

public class Application {
	//@Resource(name = "applicationUser")
	@Autowired
	private ApplicationUser applicationUser;
}

AppConfig

//긁지않은 개발자
@Configuration
@ComponentScan(basePackages = {"kr.hcat.di.vo"})
public class AppConfig {
}

 

AppMain(AppConfig)

//긁지않은 개발자
public class AppMain {
	public static void main(String[] args) {
		AbstractApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);

		Application application = context.getBean("application",Application.class);
		System.out.println(application);
        
        context.close();
	}
}

실행 결과

Application(applicationUser=ApplicationUser(name=최고관리자))

 

 

---

 

Employee

//긁지않은 개발자
@AllArgsConstructor
@NoArgsConstructor
@Data
@Component
public class EmployeeAddress {
	 
    private String street="송월길 48";
    private String city="서울 종로구";
}

EmployeeAddress

//긁지않은 개발자
@AllArgsConstructor
@NoArgsConstructor
@Data
@Component
public class Employee {
	 @Autowired
    private EmployeeAddress employeeAddress;
}

AppConfig

//긁지않은 개발자
@Configuration
@ComponentScan(basePackages = {"kr.hcat.di.vo"})
public class AppConfig {
}

 

AppMain

//긁지않은 개발자
public class AppMain {
	public static void main(String[] args) {
		AbstractApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);
		
		Employee employee = context.getBean("employee",Employee.class);
		System.out.println(employee);
		context.close();
	}
}

실행 결과

Employee(employeeAddress=EmployeeAddress(street=송월길48 21, city=서울 종로구))

 

 

 

xml

//긁지않은 개발자
<context:component-scan base-package="PackgeName"></context:component-scan>

 

AppMain

//긁지않은 개발자
AbstractApplicationContext context = new ClassPathXmlApplicationContext("XmlName.xml");

 

 

 

 

 

@어노테이션 관련 포스팅

https://h0-0cat.tistory.com/entry/XFile-26

[Spring] Spring @Annotation(어노테이션) 이해하기