Spring Boot Server & Android Client App - Chapter #2

employee database 만들기

1. model 만들기

springserver 안에 model 패키지 만들기, model 패키지 안에 employee 패키지

java class - employee 만들기

Employee.java

package com.genuinecoder.springserver.model.employee;

import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;

@Entity
public class Employee {
    @Id //id가 pk가 됨
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String name;
    private String location;
    private String branch;
    
    
    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getLocation() {
        return location;
    }

    public void setLocation(String location) {
        this.location = location;
    }

    public String getBranch() {
        return branch;
    }

    public void setBranch(String branch) {
        this.branch = branch;
    }

    @Override
    public String toString() {
        return "Employee{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", location='" + location + '\'' +
                ", branch='" + branch + '\'' +
                '}';
    }
}

왜 import javax 였는데 난 import jakarta이지 ..? 고민하며 구글링 결과

https://post.dooray.io/we-dooray/tech-insight-ko/back-end/4173/

스프링 부트 3.0 으로 전환 - Dooray! POST

나는 스프링부트 3.x 버전이다 ! 기억하기

@GeneratedValue : 기본키 매핑

자동 생성

• IDENTITY : 기본 키 생성을 데이터베이스에 위임, mysql에서 많이 씀
• SEQUENCE : 데이터 베이스 오브젝트 이용. 데이터베이스 시퀀스를 사용해서 기본키 할당, 추가적인 어노테이션으로 @SequenceGenerator 필요, oracle에서 사용
• TABLE : 별도의 키 생성 테이블을 사용, @TableGenerator 필요
• AUTO : 자동으로 기본 값으로 지정

SpringServerApplication.java

package com.genuinecoder.springserver;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;

//해당 패키지 모두 스캔
@SpringBootApplication(scanBasePackages = "com.genuinecoder.springserver")
@EnableAutoConfiguration
public class SpringServerApplication {

	public static void main(String[] args) {
		SpringApplication.run(SpringServerApplication.class, args);
	}

}

mysql workbench에서 employee table이 추가된 것 확인 가능

2. Setting up DAO (Data Access Object)

EmployeeRepository.java

package com.genuinecoder.springserver.model.employee;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface EmployeeRepository extends CrudRepository<Employee, Integer> {
    //Employee의 pk의 형태인 Integer로 값을 줌

}

EmployeeDao.java

package com.genuinecoder.springserver.model.employee;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.util.Streamable;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;

@Service
public class EmployeeDao {
    @Autowired
    private EmployeeRepository repository;

    public void save(Employee employee) {
        repository.save(employee);
    }

    public List<Employee> getAllEmployees() {
        List<Employee> employees = new ArrayList<>();
        Streamable.of(repository.findAll())
                .forEach(employees::add);
        return employees;
    }
    public void delete(Employee employee) {
        repository.deleteById(employeeId);
    }
}

Data Access Object : all the data will be accessed through this class

3. Test the repository

in order to add a new employee, we need an object of the employee dao

test에서 EmployeeDao 객체 가져오려면 autowiring 필요 !! -> @AutoWired 뭔지 자세히 알아보기

EmployeeDao에서 @Service 해놔서 autowired 가능

SpringServerApplicationTests

package com.genuinecoder.springserver;

import com.genuinecoder.springserver.model.employee.Employee;
import com.genuinecoder.springserver.model.employee.EmployeeDao;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class SpringServerApplicationTests {

	@Autowired
	private EmployeeDao employeeDao;

	@Test
	void addEmployeeTest() {
		Employee employee = new Employee();
		employee.setName("Rachel");
		employee.setLocation("Building-5");
		employee.setBranch("IT");
		employeeDao.save(employee);
	}

}

테스트 코드 돌려보고 결과 확인

여러개 추가해본 결과

 

getAllEmployees 추가

@SpringBootTest
class SpringServerApplicationTests {

	@Autowired
	private EmployeeDao employeeDao;

	// @Test
    // 얘는 test 안시키기 위해서 주석처리
	void addEmployeeTest() {
		Employee employee = new Employee();
		employee.setName("Bruce");
		employee.setLocation("Building-X");
		employee.setBranch("Security");
		employeeDao.save(employee);
	}

	@Test
	void getAllEmployees() {
		List<Employee> employees = employeeDao.getAllEmployees();
		System.out.println(employees);
	}
}

 

모두 삭제

@Test
	void getAllEmployeesAndDeleteThem() {
		List<Employee> employees = employeeDao.getAllEmployees();
		for (Employee employee : employees) {
			employeeDao.delete(employee.getId());
		}
	}

모두 삭제된것 확인