Spring Cloud (MSA) - Feign 다른 서버 값 가져오기

Feign

다른 서버에서 실행된 결과를 가져옴

---

Currency Exchange Microservice

 

CurrencyExchange

@NoArgsConstructor
@Getter
@Setter
@Entity
public class CurrencyExchange
{
    @Id
    private Long id;
    @Column(name = "currency_from")
    private String from;
    @Column(name = "currency_to")
    private String to;
    private BigDecimal conversionMultiple;
    private String environment;
}

 

CurrencyExchangeController

@RestController
public class CurrencyExchangeController
{
    @Autowired
    private CurrencyExchangeRepository currencyExchangeRepository;
    @Autowired
    private Environment environment;

    @GetMapping("/currency-exchange/from/{from}/to/{to}")
    public CurrencyExchange retrieveExchangeValue(
            @PathVariable String from,
            @PathVariable String to
    )
    {
//        CurrencyExchange currencyExchange = new CurrencyExchange();
//        currencyExchange.setId(1000L);
//        currencyExchange.setFrom(from);
//        currencyExchange.setTo(to);
//        currencyExchange.setConversionMultiple(BigDecimal.valueOf(50));

        CurrencyExchange currencyExchange = currencyExchangeRepository.findByFromAndTo(from, to);
        if(currencyExchange == null){
            throw new RuntimeException("");
        }
        currencyExchange.setEnvironment(environment.getProperty("local.server.port"));

        return currencyExchange;
    }

}

 

CurrencyExchangeRepository

public interface CurrencyExchangeRepository extends JpaRepository<CurrencyExchange,Long> {

    CurrencyExchange findByFromAndTo(String from, String to);
}

 

application.properties

spring.config.import=optional:configserver:http://localhost:8888

spring.application.name=currency-exchange
server.port=8000

spring.jpa.show-sql=true

spring.datasource.url=jdbc:h2:mem:testdb
spring.h2.console.enabled=true
# data.sql 스크립트가 실행
spring.jpa.defer-datasource-initialization=true 

 

의존성

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-config</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-starter-aop</artifactId>
</dependency>
<dependency>
    <groupId>io.github.resilience4j</groupId>
    <artifactId>resilience4j-spring-boot2</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>

 

port 2개 사용

 

 

IntelliJ VM options 추가 참고

[Java] VM arguments(VM options) 추가, 조회 - IntelliJ, Eclipse

 

실행 결과

8000, 8001 운영

 

 

---

 

 

 

Currency Conversion Microservice

의존성

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-config</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
    <scope>runtime</scope>
    <optional>true</optional>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
</dependency>

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>

*중요 : openfeign 추가

 

 

CurrencyConversionServiceApplication

@EnableFeignClients
@SpringBootApplication
public class CurrencyConversionServiceApplication {
   public static void main(String[] args) {
      SpringApplication.run(CurrencyConversionServiceApplication.class, args);
   }
}

• @EnableFeignClients : @FeignClient 를 찾기 위해 메인에서 애노테이션 사용

 

 

CurrencyConversionController

@RestController
public class CurrencyConversionController
{
    private CurrencyExchangeProxy currencyExchangeProxy;

    public CurrencyConversionController(CurrencyExchangeProxy currencyExchangeProxy) {
        this.currencyExchangeProxy = currencyExchangeProxy;
    }

    @GetMapping("/currency-converter/from/{from}/to/{to}/quantity/{quantity}")
    public CurrencyConversion calculateCurrencyConversion(
            @PathVariable String from, @PathVariable String to, @PathVariable BigDecimal quantity
            ){
        HashMap<String, String> uriVariables= new HashMap<>();
        uriVariables.put("from",from);
        uriVariables.put("to", to);

        // 해당 주소에서 데이터값 가져옴
        ResponseEntity<CurrencyConversion> responseEntity = new RestTemplate().getForEntity(
                "http://localhost:8000/currency-exchange/from/{from}/to/{to}", CurrencyConversion.class, uriVariables
        );
        CurrencyConversion currencyConversion = responseEntity.getBody();

        return new CurrencyConversion(currencyConversion.getId(),from,to,quantity,
                currencyConversion.getConversionMultiple(), quantity.multiply(quantity) ,currencyConversion.getEnvironment());
    }

    @GetMapping("/currency-converter-feign/from/{from}/to/{to}/quantity/{quantity}")
    public CurrencyConversion calculateCurrencyConversionFeign(
            @PathVariable String from, @PathVariable String to, @PathVariable BigDecimal quantity
    ){

        CurrencyConversion currencyConversion = currencyExchangeProxy.retrieveExchangeValue(from,to);

        return new CurrencyConversion(currencyConversion.getId(),from,to,quantity,
                currencyConversion.getConversionMultiple(), quantity.multiply(quantity) ,currencyConversion.getEnvironment());
    }
}

•  CurrencyConversion currencyConversion = currencyExchangeProxy.retrieveExchangeValue(from,to);
• 프록시로 주입 받아 다른 서버 서비스에서 결과를 가져옴

 

 

CurrencyExchangeProxy

@FeignClient(name = "currency-exchange", url="localhost:8000") // properties의 name
public interface CurrencyExchangeProxy
{
    @GetMapping("/currency-exchange/from/{from}/to/{to}")
    public CurrencyConversion retrieveExchangeValue(
            @PathVariable String from, @PathVariable String to
    );
}

 

CurrencyConversion

package com.javapp.microservices.currencyconversionservice.data;

import lombok.AllArgsConstructor;
import lombok.Getter;

import java.math.BigDecimal;

@AllArgsConstructor
@Getter
public class CurrencyConversion
{
    private Long id;
    private String from;
    private String to;
    private BigDecimal quantity;

    private BigDecimal conversionMultiple;
    private BigDecimal totalCalculatedAmount;
    private String environment;

    public CurrencyConversion() {
    }
}

 

 

application.properties

spring.config.import=optional:configserver:http://localhost:8888

spring.application.name=currency-conversion
server.port=8100

 

 

결과

 

 

 

---

 

 

 

네이밍서버 (유레카 서버)

 

@FeignClient(name = "currency-exchange", url="localhost:8000") // properties의 name

에서 url 이 하드코딩 돼어있음 -> 변경에 대해서 닫혀있어야됨.

 

다음 포스팅에 ----