[MSA] Catalog-service 구현

jineey·2024년 11월 8일

Spring Springboot msa

MSA

목록 보기

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Catalog-service

프로젝트 생성

기능 추가

상품 목록 조회

📌 프로젝트 생성

Dependency 추가
➡ DevTools, Lombok, Web, Eureka Discovery Client, H2 Database,
ModelMapper, Spring Data JPA
pom.xml 수정

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>2.2.224</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>org.modelmapper</groupId>
    <artifactId>modelmapper</artifactId>
    <version>2.3.8</version>
</dependency>

📌 소스코드

application.yml 수정

spring:
  application:
    name: catalog-service
  h2:
    console:
      enabled: true
      settings:
        web-allow-others: true
      path: /h2-console
  jpa:
    hibernate:
      ddl-auto: create-drop 
    show-sql: true
    generate-ddl: true
    database: h2
    defer-datasource-initialization: true
  datasource:
    driver-class-name: org.h2.Driver
    url: jdbc:h2:mem:testdb

server:
  port: 0

eureka:
  instance:
    instance-id: ${spring.application.name}:${spring.application.instance_id:${random.value}}
  client:
    fetch-registry: true
    register-with-eureka: true
    service-url:
      defaultZone: http://127.0.0.1:8761/eureka

logging:
  level:
    com.example.catalogservice: DEBUG #option

💡 추가 설명

ddl-auto: create-drop
테이블에 초기 기본 데이터를 미리 저장해두는 설정

defer-datasource-initialization: true
SPRING 2.5부터 data.sql 스크립트가 Hibernate 초기화 되기 전 실행이 되지 않아,
테이블이 자동으로 생성되지 못해서 INSERT 구문의 오류 발생으로 인해 설정 추가

data.sql 생성

insert into catalog(product_id, product_name, stock, unit_price)
    values ('CATALOG-001', 'Berlin', 100, 1500);

insert into catalog(product_id, product_name, stock, unit_price)
    values ('CATALOG-002', 'Tokyo', 110, 1000);

insert into catalog(product_id, product_name, stock, unit_price)
    values ('CATALOG-003', 'Stockholm', 120, 2000);

Entity.java 생성

package com.example.catalogservice.jpa;

import jakarta.persistence.*;
import lombok.Data;
import org.hibernate.annotations.ColumnDefault;

import java.io.Serializable;
import java.util.Date;

@Data
@Entity
@Table(name="catalog")
public class CatalogEntity implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(nullable = false, length = 120, unique = true)
    private String productId;

    @Column(nullable = false)
    private String productName;

    @Column(nullable = false)
    private Integer stock;

    @Column(nullable = false)
    private Integer unitPrice;

    @Column(nullable = false, updatable = false, insertable = false)
    @ColumnDefault(value = "CURRENT_TIMESTAMP")
    private Date createdAt;
}

Serializable (=직렬화)
자바에서 직렬화란 어떤 객체(Class)를 Byte로 변환하는 것
(cf. 역직렬화: 직렬화한 Byte를 다시 객체(Class)로 변환하여 JVM 메모리에 들고 있는 것)
➡ JAVA 객체를 JVM에서 뽑아내서 데이터를 파일과 같은 형태로 저장할 수 있게 됨
➡ 자바 시스템 내부에서 사용되는 Object 또는 Data를 외부의 자바 시스템에서도 사용할 수 있게 됨
🔗 출처: [Java] Serializable. 직렬화란 무엇일까?
🔗 출처: JAVA 직렬화(Serializable)란?

CatalogRepository.java 생성

package com.example.catalogservice.jpa;

import org.springframework.data.repository.CrudRepository;

public interface CatalogRepository extends CrudRepository<CatalogEntity, Long> {
    CatalogEntity findByProductId(String productId);
}

CatalogDto.java 생성

package com.example.catalogservice.dto;

import lombok.Data;

import java.io.Serializable;

@Data
public class CatalogDto implements Serializable {
    private String productId;
    private Integer qty;
    private Integer unitPrice;
    private Integer totalPrice;

    private String orderId;
    private String userId;
}

ResponseCatalog.java 생성

package com.example.catalogservice.vo;

import com.fasterxml.jackson.annotation.JsonInclude;
import lombok.Data;

import java.util.Date;

@Data
@JsonInclude(JsonInclude.Include.NON_NULL) //NUll값 반환하지 않음
public class ResponseCatalog {
    private String productId;
    private String productName;
    private Integer unitPrice;
    private Integer stock;
    private Date createdAt;
}

📌 상품 목록 조회 기능

CatalogService.java 인터페이스 생성

package com.example.catalogservice.service;

import com.example.catalogservice.jpa.CatalogEntity;

public interface CatalogService {
    Iterable<CatalogEntity> getAllCatalogs();
}

CatalogServiceImpl.java 생성

package com.example.catalogservice.service;

import com.example.catalogservice.jpa.CatalogEntity;
import com.example.catalogservice.jpa.CatalogRepository;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Data
@Slf4j
@Service
public class CatalogServiceImpl implements CatalogService {

    CatalogRepository catalogRepository;

    @Autowired
    public CatalogServiceImpl(CatalogRepository catalogRepository) {
        this.catalogRepository = catalogRepository;
    }

    @Override
    public Iterable<CatalogEntity> getAllCatalogs() {
        return catalogRepository.findAll();
    }
}

CatalogController.java 생성

package com.example.catalogservice.controller;

import com.example.catalogservice.jpa.CatalogEntity;
import com.example.catalogservice.service.CatalogService;
import com.example.catalogservice.vo.ResponseCatalog;
import org.modelmapper.ModelMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

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

@RestController
@RequestMapping("/catalog-service")
public class CatalogController {
    Environment env;
    CatalogService catalogService;

    @Autowired
    public CatalogController(Environment env, CatalogService catalogService) {
        this.env = env;
        this.catalogService = catalogService;
    }

    @GetMapping("/health_check")
    public String status(){
        return String.format("It's Working in Catalog Service on PORT %s",
                            env.getProperty("local.server.port"));
    }

    @GetMapping("/catalogs")
    public ResponseEntity<List<ResponseCatalog>> getCatalogs(){
        Iterable<CatalogEntity> catalogList = catalogService.getAllCatalogs();

        List<ResponseCatalog> result = new ArrayList<>();
        catalogList.forEach(v -> {
            result.add(new ModelMapper().map(v, ResponseCatalog.class));
        });
        return ResponseEntity.status(HttpStatus.OK).body(result);
    }

}

API Gateway의 application.yml 수정

spring:
  application:
    name: apigateway-service
  cloud:
    gateway:
      routes:
        - id: catalog-service
          uri: lb://CATALOG-SERVICE
          predicates:
            - Path=/catalog-service/**