SB_Properties(@Values)

Main

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;

import com.example.dto.User;
import com.example.service.DBService;

@SpringBootApplication	//서브패키지에 있는 @JavaConfig를 자동생성
public class Application {

	public static void main(String[] args) {
		ApplicationContext ctx = SpringApplication.run(Application.class, args);
		User user = (User) ctx.getBean("userDTO");
		System.out.println(user);
		
	}

}

JavaConfig

package com.example.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.example.dto.User;
import com.example.service.DBService;

@Configuration
public class JavaConfig {

	@Bean(value = "userDTO")	//설정 변수:	application-properties 설정:	파일 자동 로딩
	public User user() {
		return new User();
	}
	
	
	
}

User(DTO)

package com.example.dto;

import org.springframework.beans.factory.annotation.Value;

public class User {

		@Value("${user.username}")
		String username;
		@Value("${user.age}")
		int age;
		@Override
		public String toString() {
			return "user [username=" + username + ", age=" + age + "]";
		}
		
	
}

Service

package com.example.service;

import java.util.Arrays;
import java.util.List;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

//@Service 없음
public class DBService {

	public void xxx() {	//Configuration에 의해 시작할 때 발동
	        System.out.println("initMethod.xxx");
	    }
	    public void yyy() {	//Configuration에 의해 끝날 때 발동
	        System.out.println("destoryMethod.xxx");
	    }
	public List<String> list() { //Main에서 실행
	        return Arrays.asList("홍길동", "이순신");
	    }
	
	
	@PostConstruct
	public void init() {
		System.out.println("post init");
	}
	
	@PreDestroy
	public void dest() {
		System.out.println("pre dest");
	}
	
	public void destroy() throws Exception{
		System.out.println("over dest");
	}
	
	public void afterPropertiesSet() throws Exception{
		System.out.println("afterPro");
	}

}

application.properties

user.username=\uD64D\uAE38\uB3D9
user.age=20