TIL - 25.12.29

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학습 키워드

• Spring 코드 실습
• 알고리즘 풀이

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Spring 코드 실습

BaseEntity

package com.example.examplemember.entity;

import jakarta.persistence.*;
import lombok.Getter;
import org.springframework.data.annotation.CreatedDate;
import org.springframework.data.annotation.LastModifiedDate;
import org.springframework.data.jpa.domain.support.AuditingEntityListener;

import java.time.LocalDateTime;

@Getter
@MappedSuperclass
@EntityListeners(AuditingEntityListener.class)
public abstract class BaseEntity {

    @CreatedDate
    @Column(updatable = false)
    @Temporal(TemporalType.TIMESTAMP)
    private LocalDateTime createdAt;

    @LastModifiedDate
    @Temporal(TemporalType.TIMESTAMP)
    private LocalDateTime modifiedAt;
}

Member

package com.example.examplemember.entity;

import jakarta.persistence.*;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.NoArgsConstructor;

@Getter
@Entity
@Table(name = "members")
@NoArgsConstructor(access = AccessLevel.PROTECTED)
public class Member extends BaseEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long memberId;
    private String name;

    public Member(String name) {
        this.name = name;
    }

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


}

ExampleMemberApplication

package com.example.examplemember;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.jpa.repository.config.EnableJpaAuditing;

@EnableJpaAuditing
@SpringBootApplication
public class ExampleMemberApplication {

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

}

createAt & modifiedAt 정보를 가져올 수 있도록, BaseEntity를 생성하였습니다. 이를 Member 클래스에 상속하고, ExampleMemberApplication 클래스에 어노테이션을 생성하여 사용했습니다.

application.properties

spring.application.name=Example-Member

spring.datasource.url=jdbc:mysql://localhost:3306/database
spring.datasource.username=username
spring.datasource.password=password
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQLDialect
spring.jpa.hibernate.ddl-auto=create
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true

application.properties 파일에 코드를 작성하여 mySQL과 연결하였습니다.

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알고리즘 풀이

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        int a = sc.nextInt();
        int b = sc.nextInt();
        
        System.out.println(a + b);
        System.out.println(a - b);
        System.out.println(a * b);
        System.out.println(a / b);
        System.out.print(a % b);
    }
}