nacos启动

参考官网启动，账号和密码默认为nacos

创建提供提供者

创建openfegin提供者，fallback进行降级处理

``

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.cloud.openfeign.SpringQueryMap;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.*;

import javax.validation.Valid;
import java.util.List;

/**
 * @author jxc
 * 2022/8/12
 */
@FeignClient(name = Constants.SERVER, path = Constants.BASE_PATH, fallbackFactory = DefaultTestBizClient.class)
public interface TestBizClient {

    /**
     * <pre>
     *     测试表列表
     * </pre>
     *
     * @param query 查询条件
     * @return 测试列表
     */
    @GetMapping("tests")
    PageResult<List<TestVO>> queryPage(@SpringQueryMap TestBizQuery query);

    /**
     * <pre>
     *     测试表新增
     * </pre>
     *
     * @param req 入参
     * @return id
     */
    @PostMapping("tests")
    Resp<Integer> saveTest(@RequestBody @Valid TestBizReq req);

    /**
     * <pre>
     *     测试表更新
     * </pre>
     *
     * @param req 入参
     * @return 更新行数
     */
    @PutMapping("tests")
    Resp<Integer> updateTest(@RequestBody @Validated(Update.class) TestBizReq req);

    /**
     * <pre>
     *     测试表删除
     * </pre>
     *
     * @param testId id
     * @return 更新行数
     */
    @DeleteMapping("tests/{testId}")
    Resp<Integer> deleteById(@PathVariable("testId") Integer testId);
}

pom添加nacos的配置和启动文件增加配置

spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

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

<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<version>2.1.1.RELEASE</version>
</dependency>

调用者

启动类添加

@EnableDiscoveryClient
@EnableFeignClients

pom配置添加

      <dependency>
          <groupId>org.springframework.cloud</groupId>
          <artifactId>spring-cloud-loadbalancer</artifactId>
      </dependency>
            <dependency>
          <groupId>com.alibaba.cloud</groupId>
          <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
          <version>2.1.1.RELEASE</version>
          <exclusions>
              <exclusion>
                  <groupId>org.springframework.cloud</groupId>
                  <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
              </exclusion>
          </exclusions>
      </dependency>

配置文件添加

spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848

注意事项

如果提示负载均衡客户端选择错误，主要是包冲出，排查很久了参考了文章解决问题。https://blog.csdn.net/weixin_51626435/article/details/115012925

java.lang.AbstractMethodError: Receiver class org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient does not define or inherit an implementation of the resolved method 'abstract org.springframework.cloud.client.ServiceInstance choose(java.lang.String, org.springframework.cloud.client.loadbalancer.Request)' of interface org.springframework.cloud.client.loadbalancer.ServiceInstanceChoose

引入包的时候进行排除