SpringBoot MSA (10) - MicroService / UserService H2 연결 (1)

API Gateway -> Discovery Server -> MicroService (UserService) 를 만들어보자

 

Project 생성 및 4가지 Dependency 추가

 

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.2</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>user-service</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>user-service</name>
    <description>user-service</description>
    <properties>
        <java.version>11</java.version>
        <spring-cloud.version>2020.0.0</spring-cloud.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

application.yml

> 서버 포트 및 Eureka Server 설정

server:
  port: 0

spring:
  application:
    name: user-service

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

 

UserServiceApplication.java

> EurekaServerClient 활성

package com.example.userservice;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class UserServiceApplication {

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

}

 

 

간단하게 API 상태를 확인하는 기능을 구현해보자

controller > UserController.java

package com.example.userservice.controller;

import com.example.userservice.vo.Greeting;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/")
public class UserController {

    private Environment env;

    @Autowired
    private Greeting greeting;

    @Autowired
    public UserController(Environment env) {
        this.env = env;
    }

    @GetMapping("/health_check")
    public String status() {
        return "It's Working in User Service";
    }

    @GetMapping("/welcome")
    public String welcome() {
//        return env.getProperty("greeting.message");
        return greeting.getMessage();
    }

}

VO 객체를 만들어보자.

package com.example.userservice.vo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Greeting {
    @Value("${greeting.message}")
    private String message;

}

 

패키지 구조

 

실행전 앞에서 만들었던 Client를 기록하는 Discovery Service를 실행시켜야된다.

터미널에서

discovery-service로 이동하여 pom.xml의 위치와 동일한 곳에서 실행! : mvn spring-boot:run

그리고 UserService 실행

 

H2 데이터베이스 연결

pom.xml 에 dependency 추가

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.4.200</version>
    <scope>runtime</scope>
</dependency>

application.yml

h2 데이터베이스 사용하기 위한 설정파일 세팅

spring:
  application:
    name: user-service
  h2:
    console:
      enabled: true
      settings:
        # 외부에서 접속 허용
        web-allow-others: true
      # 웹 브라우저의 h2 콘솔의 주소
      path: /h2-console
  datasource:
    driver-class-name: org.h2.Driver
    url: jdbc:h2:mem:testdb
#    username: sa
#    password: 1234

 

user-service 재실행 후 user-service에 h2 콘솔 path 접근

Test Connection 클릭 후 오류 발생 시

데이터베이스의 보안상의 문제로 버전을 낮추면 해결이 가능하다. (현재는 테스트이기때문에 버전을 낮추겠습니다.)

pom.xml

h2database의 버전을 변경한다. ( 1.4.200 -> 1.3.176 )

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.3.176</version>
    <scope>runtime</scope>
</dependency>

JDBC URL 변경 ( tcp -> jdbc:h2:mem:testdb )

> Test Connection

Connect 시 성공적으로 접속되는 것을 알 수 있다.