问题：

我有一个项目，其中AlumniHub_activity服务会调用AlumniHub_auth服务，代码如下：

@PostMapping("/addActivity")
public String addActivity(HttpServletRequest request){
    String token = request.getHeader("token");
    return restTemplate.postForObject("http://AlumniHub-auth/getIdByToken?token=" + token,null, String.class);
}

但是老是报错

Receiver class org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerCl

解决方案：

使用loadbalancer且要在配置文件中排除ribbon，因为spring-cloud-starter-alibaba-nacos-discovery自带ribbon

  <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        <!-- 使用spring loadbalancer，弃用ribbon -->
        <exclusions>
            <exclusion>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

package cn.edu.hbliti.alumnihub_activity;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
@EnableDiscoveryClient
public class AlumniHubActivityApplication {

@Bean
@LoadBalanced
public RestTemplate restTemplate() {
    return new RestTemplate();
}
public static void main(String[] args) {
    SpringApplication.run(AlumniHubActivityApplication.class, args);
    System.out.println("(♥◠‿◠)ﾉﾞ  活动管理中心启动成功   ლ(´ڡ`ლ)ﾞ  \n" +
            """
                    ───▐▀▄───────▄▀▌───▄▄▄▄▄▄▄
                    ───▌▒▒▀▄▄▄▄▄▀▒▒▐▄▀▀▒██▒██▒▀▀▄
                    ──▐▒▒▒▒▀▒▀▒▀▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▀▄
                    ──▌▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▄▒▒▒▒▒▒▒▒▒▒▒▒▀▄
                    ▀█▒▒▒█▌▒▒█▒▒▐█▒▒▒▀▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▌
                    ▀▌▒▒▒▒▒▒▀▒▀▒▒▒▒▒▒▀▀▒▒▒▒▒▒▒▒▒▒▒▒▒▒▐───▄▄
                    ▐▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▌▄█▒█
                    ▐▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒█▒█▀
                    ▐▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒█▀""");
}

}

然后就可以启动成功了