[36일차] 스프링

 

 

🧡2022-08-10🧡

 

 

https://blog.naver.com/writer0713/220700687650

 

 

[java] POJO란?

 

EJBC (Enterprise Java Bean)

자바 개발자들이 피곤해지기 시작.. EJB를 만들때 기본적인 객체지향 개념이 잘못된 ,. 클래스를 잘못 만들어서

보안 관련 EJB extend 얽히고 섥힌.. 줄줄이 끌려오는게 많아서 무거워짐 -> 클래스 설계 잘못

 

객체지향 컨퍼런스 

POJO Plain Java Object

객체지향 개념을 지향하면서 자바 오브젝트의 특징을 갖고있는..  그럴듯하니깐 포조운동이 일어남

 

기술면접에서도 나올 수 있음. 라이브러리와 프레임워크의 차이가 뭐냐,,,

라이브러리에도 나와도 좋고 프레임워크에서 나와도 좋은

라이브러리는 특정한 기능들 함수나 클래스로 끌어다 쓰는 것

ex) 태그 라이브러리 JAR 파일.. 

프레임워크는 라이브러리가 모여서 와꾸.. 탁 트인 것 

어떤 기능은 여기다가 적어라 틀에 못벗어남.. 물리적으로 보면 프레임워크는 라이브러리의 집합체

포조를 기반으로 한 프레임워크가 등장한다.

structs, spring 이 등장하였다 ! !

시간이 지나면서 스프링이 완성됨

Spring 자바의 봄을 맞이했다.. 해서 스프링

 

스프링?? 웹 애플리케이션과 무슨 상관이냐??

스프링이란 DI와 AOP를 지원하는 POJO 기반의 Framework이다!

 

DI가 뭐고 AOP가 무엇인지 알아야 스프링을 이해할 수 있다.

 

1. DI (Dependency Injection = 의존 주입)

스프링이 아니고 객체지향 디자인과 관련되어있음.

 

 

메이븐 프로젝트 pom 바꾸기

 

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.gyuone</groupId>
  <artifactId>dISample</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <properties>
  	<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  	<maven.compiler.source>11</maven.compiler.source>
  	<maven.compiler.target>11</maven.compiler.target>
  </properties>
</project>

https://mvnrepository.com/artifact/org.springframework/spring-context/5.3.22

 

 

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.gyuone</groupId>
	<artifactId>dISample</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<maven.compiler.source>11</maven.compiler.source>
		<maven.compiler.target>11</maven.compiler.target>
	</properties>
	<dependencies>
		<!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-context</artifactId>
			<version>5.3.22</version>
		</dependency>
	</dependencies>
</project>

 

 

 

끌고 온거 확인

---

 

 

depends on 의존 관계 memberDao는 MRS의 dependency..

memberRegisterService는 memberDao가 꼭 들어가야하는 dependency

 

dependency.. 의존, 의존성

 

---

https://github.com/GyuWonLee/dIProject

GitHub - GyuWonLee/dIProject

 

com.gyuone.main

MainForAssembler.java

package com.gyuone.main;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.DuplicateFormatFlagsException;

import com.gyuone.common.MemberNotFoundException;
import com.gyuone.common.WrongIdPasswordException;
import com.gyuone.model.RegisterRequest;
import com.gyuone.service.Assembler;
import com.gyuone.service.ChangePasswordService;
import com.gyuone.service.MemberRegisterService;

public class MainForAssembler {
	private static Assembler assembler = new Assembler();
	
	public static void main(String[] args) throws Exception{
		BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
		while(true) {
			System.out.print("명령어 입력 : ");
			String command = reader.readLine();
			if(command.equalsIgnoreCase("exit")) {
				System.out.println("프로그램 종료");
				break;
			}
			if(command.startsWith("new ")) {
				processNewCommand(command.split(" "));
				continue;
			}else if(command.startsWith("change ")) {
				processChangeCommand(command.split(" "));
				continue;
			}
			printHelp();
		}
	}
	
	private static void printHelp() {
		System.out.println();
		System.out.println("잘못된 명령입니다. 아래 명령어 사용법을 확인하세요.");
		System.out.println("명령어 사용법:");
		System.out.println("new 이메일 이름 암호 암호확인");
		System.out.println("change 이메일 현재비번 변경비번");
		System.out.println();
	}
	
	private static void processNewCommand(String[] arg) {
		if(arg.length != 5) {
			printHelp();
			return;
		}
		MemberRegisterService regSvc = assembler.getMemberRegisterService();
		RegisterRequest req = new RegisterRequest();
		req.setEmail(arg[1]);
		req.setName(arg[2]);
		req.setPassword(arg[3]);
		req.setConfirmPassword(arg[4]);
		
		if(!req.isPasswordEqualToConfirmPassword()) {
			System.out.println("암호 확인이 맞지 않습니다.");
			System.out.println();
			return;
		}
		try {
			regSvc.register(req);
			System.out.println("등록 완료");
			System.out.println();
		} catch (DuplicateFormatFlagsException e) {
			// TODO: handle exception
			System.out.println("이미 존재하는 이메일입니다.");
			System.out.println();
		}
	}
	
	private static void processChangeCommand(String[] arg) {
		if(arg.length != 4) {
			printHelp();
			return;
		}
		ChangePasswordService changePwdSvc = assembler.getChangePasswordService();
		try {
			changePwdSvc.changePassword(arg[1], arg[2], arg[3]);
			System.out.println("암호 변경 완료");
		} catch (MemberNotFoundException e) {
			// TODO: handle exception
			System.out.println("존재하지 않는 이메일입니다.");
			System.out.println();
		} catch (WrongIdPasswordException e) {
			System.out.println("이메일과 암호 불일치");
			System.out.println();
		}
	}
}

 

com.gyuone.common

DuplicateMemverException.java

package com.gyuone.common;

public class DuplicateMemberException extends RuntimeException{
	public DuplicateMemberException(String message) {
		super(message);
	}
}

 

MemberNotFoundException.java

package com.gyuone.common;

public class MemberNotFoundException extends RuntimeException{

}

 

WrongIdPasswordException.java

package com.gyuone.common;

public class WrongIdPasswordException extends RuntimeException{
	
}

 

com.gyuone.dao

MemberDao.java

package com.gyuone.dao;
import java.util.HashMap;
import java.util.Map;

import com.gyuone.model.Member;

public class MemberDao {
	private static long nextId = 0;
	
	private Map<String, Member> map = new HashMap<>();
	
	public Member selectByEmail(String email) {
		return map.get(email);
	}
	
	public void insert(Member member) {
		member.setId(++nextId);
		map.put(member.getEmail(), member);
	}
	
	public void update(Member member) {
		map.put(member.getEmail(), member);
	}
}

 

 

com.gyuone.model

Member.java

package com.gyuone.model;

import java.time.LocalDateTime;

import com.gyuone.common.WrongIdPasswordException;

public class Member {
	private long id;
	private String email;
	private String password;
	private String name;
	private LocalDateTime registerDateTime;

	public Member(String email, String password, String name, LocalDateTime registerDateTime) {
		super();
		this.email = email;
		this.password = password;
		this.name = name;
		this.registerDateTime = registerDateTime; // 생성자 만들어주기
	}

	public long getId() {
		return id;
	}

	public void setId(long id) {
		this.id = id;
	}

	public String getEmail() {
		return email;
	}

	public String getPassword() {
		return password;
	}

	public String getName() {
		return name;
	}

	public LocalDateTime getRegisterDateTime() {
		return registerDateTime;
	}
	
	public void changePassword(String oldPassword, String newPassword) {
		if(!password.equals(oldPassword)) {
			throw new WrongIdPasswordException();
		}
		this.password = newPassword;
	}

}

 

 

RegisterRequest.java

package com.gyuone.model;

public class RegisterRequest {
	private String email;
	private String password;
	private String confirmPassword;
	private String name;

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public String getConfirmPassword() {
		return confirmPassword;
	}

	public void setConfirmPassword(String confirmPassword) {
		this.confirmPassword = confirmPassword;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
	
	public boolean isPasswordEqualToConfirmPassword() {
		return password.equals(confirmPassword);
	}
	

}

 

com.gyuone.service

Assembler.java

package com.gyuone.service;

import com.gyuone.dao.MemberDao;

public class Assembler {
	private MemberDao memberDao;
	private MemberRegisterService regSvc;
	private ChangePasswordService pwdSvc;
	
	public Assembler() {
		memberDao = new MemberDao();
		regSvc = new MemberRegisterService(memberDao);
		pwdSvc = new ChangePasswordService();
		pwdSvc.setMemberDao(memberDao);
	}

	public MemberDao getMemberDao() {
		return memberDao;
	}

	public MemberRegisterService getMemberRegisterService() {
		return regSvc;
	}

	public ChangePasswordService getChangePasswordService() {
		return pwdSvc;
	}
	
	
}

 

ChangePasswordService.java

package com.gyuone.service;

import com.gyuone.common.MemberNotFoundException;
import com.gyuone.dao.MemberDao;
import com.gyuone.model.Member;

public class ChangePasswordService {
	private MemberDao memberDao;

	public void setMemberDao(MemberDao memberDao) {
		this.memberDao = memberDao;
	}
	
	public void changePassword(String email, String oldPwd, String newPwd) {
		Member member = memberDao.selectByEmail(email);
		if(member == null) {
			throw new MemberNotFoundException();
		}
		member.changePassword(oldPwd, newPwd);
		memberDao.update(member);
	}
}

 

 

MemberRegisterService.java

package com.gyuone.service;

import java.time.LocalDateTime;

import com.gyuone.common.DuplicateMemberException;
import com.gyuone.dao.MemberDao;
import com.gyuone.model.Member;
import com.gyuone.model.RegisterRequest;

public class MemberRegisterService {
//	private MemberDao memberDao = new MemberDao(); // 강한 결합

	private MemberDao memberDao;
	
	public MemberRegisterService(MemberDao memberDao) { // 생성자를 통해서 의존을 주입.. 생성자 의존 주입 = DI
		this.memberDao = memberDao;
	}
	
	public long register(RegisterRequest req) {
		Member member = memberDao.selectByEmail(req.getEmail());
		
		if(member != null) {
			throw new DuplicateMemberException("dup email " + req.getEmail());
		}
		
		Member newmember = new Member(req.getEmail(), req.getPassword(), req.getName(), LocalDateTime.now());
		memberDao.insert(newmember);
		return newmember.getId();
	}
}

 

---

 MRS와 MDao가강하게 결합되어 있다. 강하게 strongly coupled = > 결합단계를 약하게 만들어야한다.