Microservices with Spring Boot - Part 3 - Creating Currency Conversion Microservice

  package com.girishgodage.springboot.microservice.example.currencyconversion;

  import org.springframework.cloud.openfeign.FeignClient;
  import org.springframework.cloud.netflix.ribbon.RibbonClient;
  import org.springframework.web.bind.annotation.GetMapping;
  import org.springframework.web.bind.annotation.PathVariable;

  @FeignClient(name="forex-service" url="localhost:8000")
  public interface CurrencyExchangeServiceProxy {
    @GetMapping("/currency-exchange/from/{from}/to/{to}")
    public CurrencyConversionBean retrieveExchangeValue
      (@PathVariable("from") String from, @PathVariable("to") String to);
  }

  package com.girishgodage.springboot.microservice.example.currencyconversion;
  import java.math.BigDecimal;

  public class CurrencyConversionBean {
    private Long id;
    private String from;
    private String to;
    private BigDecimal conversionMultiple;
    private BigDecimal quantity;
    private BigDecimal totalCalculatedAmount;
    private int port;

    public CurrencyConversionBean() {

    }

    public CurrencyConversionBean(Long id, String from, String to, BigDecimal conversionMultiple, BigDecimal quantity,
        BigDecimal totalCalculatedAmount, int port) {
      super();
      this.id = id;
      this.from = from;
      this.to = to;
      this.conversionMultiple = conversionMultiple;
      this.quantity = quantity;
      this.totalCalculatedAmount = totalCalculatedAmount;
      this.port = port;
    }

    public Long getId() {
      return id;
    }

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

    public String getFrom() {
      return from;
    }

    public void setFrom(String from) {
      this.from = from;
    }

    public String getTo() {
      return to;
    }

    public void setTo(String to) {
      this.to = to;
    }

    public BigDecimal getConversionMultiple() {
      return conversionMultiple;
    }

    public void setConversionMultiple(BigDecimal conversionMultiple) {
      this.conversionMultiple = conversionMultiple;
    }

    public BigDecimal getQuantity() {
      return quantity;
    }

    public void setQuantity(BigDecimal quantity) {
      this.quantity = quantity;
    }

    public BigDecimal getTotalCalculatedAmount() {
      return totalCalculatedAmount;
    }

    public void setTotalCalculatedAmount(BigDecimal totalCalculatedAmount) {
      this.totalCalculatedAmount = totalCalculatedAmount;
    }

    public int getPort() {
      return port;
    }

    public void setPort(int port) {
      this.port = port;
    }

  }

  package com.girishgodage.springboot.microservice.example.currencyconversion;

  import java.math.BigDecimal;
  import java.util.HashMap;
  import java.util.Map;

  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.http.ResponseEntity;
  import org.springframework.web.bind.annotation.GetMapping;
  import org.springframework.web.bind.annotation.PathVariable;
  import org.springframework.web.bind.annotation.RestController;
  import org.springframework.web.client.RestTemplate;

  @RestController
  public class CurrencyConversionController {

    private Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private CurrencyExchangeServiceProxy proxy;

    @GetMapping("/currency-converter/from/{from}/to/{to}/quantity/{quantity}")
    public CurrencyConversionBean convertCurrency(@PathVariable String from, @PathVariable String to,
        @PathVariable BigDecimal quantity) {

      Map<String, String> uriVariables = new HashMap<>();
      uriVariables.put("from", from);
      uriVariables.put("to", to);

      ResponseEntity<CurrencyConversionBean> responseEntity = new RestTemplate().getForEntity(
          "http://localhost:8000/currency-exchange/from/{from}/to/{to}", CurrencyConversionBean.class,
          uriVariables);

      CurrencyConversionBean response = responseEntity.getBody();

      return new CurrencyConversionBean(response.getId(), from, to, response.getConversionMultiple(), quantity,
          quantity.multiply(response.getConversionMultiple()), response.getPort());
    }

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

      CurrencyConversionBean response = proxy.retrieveExchangeValue(from, to);

      logger.info("{}", response);

      return new CurrencyConversionBean(response.getId(), from, to, response.getConversionMultiple(), quantity,
          quantity.multiply(response.getConversionMultiple()), response.getPort());
    }

  }

  package com.girishgodage.springboot.microservice.example.currencyconversion;

  import org.springframework.cloud.openfeign.FeignClient;
  import org.springframework.cloud.netflix.ribbon.RibbonClient;
  import org.springframework.web.bind.annotation.GetMapping;
  import org.springframework.web.bind.annotation.PathVariable;

  @FeignClient(name="forex-service" url="localhost:8000")
  public interface CurrencyExchangeServiceProxy {
    @GetMapping("/currency-exchange/from/{from}/to/{to}")
    public CurrencyConversionBean retrieveExchangeValue
      (@PathVariable("from") String from, @PathVariable("to") String to);
  }

  package com.girishgodage.springboot.microservice.example.currencyconversion;

  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
  import org.springframework.cloud.netflix.feign.EnableFeignClients;

  @SpringBootApplication
  @EnableFeignClients("com.girishgodage.springboot.microservice.example.currencyconversion")
  public class SpringBootMicroserviceCurrencyConversionApplication {

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

  package com.girishgodage.springboot.microservice.example.currencyconversion;

  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.springframework.boot.test.context.SpringBootTest;
  import org.springframework.test.context.junit4.SpringRunner;

  @RunWith(SpringRunner.class)
  @SpringBootTest
  public class SpringBootMicroserviceCurrencyConversionApplicationTests {

    @Test
    public void contextLoads() {
    }

  }