一、在Maven pom.xml文件中添加
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-feign</artifactId>
</dependency>
二、創建一個接口
注意:@FeignClient註解中的cloud-service爲Eureka註冊的服務名。
原理:在Eureka註冊的cloud-service工程中,也有一個controller有相同的findById方法與參數,在此通過Feign接口去跟service-cloud的controller方法匹配
package com.itmuch.cloud;
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
@FeignClient(name="cloud-service") // 服務端提供者的name
public interface UserFeignClient {
@GetMapping("/get/{id}")
public User findById(@PathVariable("id") Long id);
}
三、Controller 調用
/**
* #3 第三種 基於 Feign 服務方式來調用
* @param id
* @return
*/
@GetMapping("/feign/{id}")
public User findByIdFeign(@PathVariable Long id) {
return userFeignClient.findById(id);
}
四、主程序
爲其添加@EnableFeignClients註解
package com.itmuch.cloud;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
public class CloudConsumerApplication {
@Bean // 等價於 RestTemplate restTemplate = new RestTemplate();
@LoadBalanced // Ribbon 負載均衡
public RestTemplate restTemplate() {
return new RestTemplate();
}
public static void main(String[] args) {
SpringApplication.run(CloudConsumerApplication.class, args);
}
}