Using the open feign development interface, the direct startup fails, and the following exception is thrown:

nested exception is java.lang.IllegalStateException: No Feign Client for loadBalancing defined. Did you forget to include spring-cloud-starter-loadbalancer?

The problem is obviously that spring cloud starter loadbalancer is not added, so in the pom.xml Add the following dependencies to:

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

After re importing the dependency, it starts successfully, but the calling interface still reports an error:

java.lang.AbstractMethodError: org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.choose(Ljava/lang/String;Lorg/springframework/cloud/client/loadbalancer/Request;)Lorg/springframework/cloud/client/ServiceInstance;

This is because spring cloud replaces the load balancing component from ribbon to loadbalancer. You need to exclude the ribbon component in spring cloud starter Alibaba Nacos discovery, otherwise loadbalancer will not work.

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

After re importing the dependency, restart the project and call successfully.