openFeign简介

openFeign使用

在消费者pom.xml引入如下依赖

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

在启动类上加注解@EnableFeignClients

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

在服务提供者中有这样一个controller

@RestController
public class ProviderController {
    @RequestMapping("/hello")
    public String helloNacos(){
        return "hello world";
    }
}

在服务消费者中新建一个接口service，其中nacos-provider就是服务提供者中spring.application.name的值，/hello就是服务提供者中Controller的@RequestMapping("/hello")的值

@Component
@FeignClient(name = "nacos-provider")
public interface ConsumerService {
    @GetMapping(value = "/hello")
    String helloNacos();
}

在服务消费者controller中调用

@RestController
public class ConsumerController {
    @Autowired
    private ConsumerService consumerService;

    @GetMapping(value = "/helloFeign")
    public String getPayById(){
       return consumerService.helloNacos();
    }
}

测试：http://localhost:8083/helloFeign

页面输出：hello world

feign自带负载均衡