背景
Spring Cloud OpenFeign 是一个 HTTP 客户端, 用来发送请求获取数据.
Spring Cloud Gateway 需要连接 Eurake 或其他服务发现组件读取路由表.
安装
引入以下依赖.
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>启动类添加 @EnableFeignClients
@SpringBootApplication
@EnableFeignClients
public class ConversionServiceApplication {
public static void main(String[] args) {
SpringApplication.run(ConversionServiceApplication.class, args);
}
}使用
定义一个接口.
//@FeignClient(name="currency-exchange", url="localhost:8000") // 普通请求
@FeignClient(name = "exchange-service") // 负载均衡
public interface ConversionExchangeProxy {
@GetMapping("/exchange/get")
public String retrieveExchangeValue();
}使用它获取数据.
@RestController
public class ConversionController {
@Autowired
private ConversionExchangeProxy proxy;
@GetMapping("/exchange")
public String exchangeValue() {
return proxy.retrieveExchangeValue();
}
}错误拦截
https://stackoverflow.com/questions/55020389/spring-feign-client-exception-handling
https://www.javacodemonk.com/feign-exception-handling-spring-cloud-20d17f69
https://www.baeldung.com/spring-cloud-openfeign
参考
https://docs.spring.io/spring-cloud-openfeign/docs/current/reference/html/