http客户端Feign

定义和使用Feign客户端

    <!--    feign客户端依赖-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

package cn.itcast.order.clients;


import cn.itcast.order.pojo.User;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;

@FeignClient("userService")
public interface UserClient {

    @GetMapping("/user/{id}")
    User findById(@PathVariable("id") Long id);

}

自定义Feign的配置

feign:
  client:
    config:
      default:
        logger-level: FULL

package cn.itcast.order.config;

import feign.Logger;
import org.springframework.context.annotation.Bean;

public class DefaultFeignConfiguration {

    @Bean
    public Logger.Level logLevel(){
        return Logger.Level.BASIC;

    }
}

Feign的性能优化

    <!--    引入httpclient依赖-->
        <dependency>
            <groupId>io.github.openfeign</groupId>
            <artifactId>feign-httpclient</artifactId>
        </dependency>

feign:
  httpclient:
    enabled: true   # 支持httpclient的开关
    max-connections: 200 # 最大连接数
    max-connections-per-route: 50 # 单个路径的最大连接数

feign的最佳实践

@EnableFeignClients(clients = UserClient.class,defaultConfiguration = DefaultFeignConfiguration.class)