SpringCloudAlibaba - RPC远程调用OpenFeign

OpenFeign是一个Web声明式的Http客户端调用工具,提供接口和注解形式调用。开发微服务,免不了需要服务间调用。Spring Cloud框架提供了RestTemplate和FeignClient两个方式完成服务间调用,本文简要介绍如何使用OpenFeign完成服务间调用,下面开始进行整合:

首先基于IDEA建立maven聚合项目如下图:

SpringCloudAlibaba - RPC远程调用OpenFeign_第1张图片

其中,springcloud-alibaba-parent是父项目,存放一些共同依赖,service-api,service-implspringcloud-alibaba-parent的module子模块,service-api-member,service-api-orderservice-api的module子模块,service-impl-member,service-impl-orderservice-impl的module子模块。

  在springcloud-alibaba-parent引入如下公共依赖:



    4.0.0

    com.xyy
    springcloud-alibaba-parent
    pom
    1.0-SNAPSHOT
    
        service-api
        service-impl
    

    
        org.springframework.boot
        spring-boot-starter-parent
        2.0.0.RELEASE
    

    
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.cloud
            spring-cloud-starter-alibaba-nacos-discovery
            0.2.2.RELEASE
        
        
            org.springframework.cloud
            spring-cloud-starter-openfeign
            2.0.0.RELEASE
        
    

  service-impl-member依赖如下:


    
        com.xyy
        service-api-member
        1.0-SNAPSHOT
    

  service-impl-order依赖如下:


    
        com.xyy
        service-api-member
        1.0-SNAPSHOT
    
    
        com.xyy
        service-api-order
        1.0-SNAPSHOT
    

  service-impl-member配置文件如下:

spring:
  application:
    # 服务名称
    name: service-member
  cloud:
    nacos:
      discovery:
        # nacos注册地址
        server-addr: 127.0.0.1:8848
server:
  port: 8081

  service-impl-order配置文件如下:

spring:
  application:
    # 服务名称
    name: service-order
  cloud:
    nacos:
      discovery:
        # nacos注册地址
        server-addr: 127.0.0.1:8848
server:
  port: 8090

  在service-api-member编写Member服务:

package com.xyy;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;

public interface MemberService {
    /**
     * 提供我们发布的接口
     * @param userId
     * @return
     */
    @GetMapping("/getUser")
    String getUser(@RequestParam("userId") Integer userId);
}

  在service-impl-member编写实现类:

package com.xyy.impl;

import com.xyy.MemberService;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MemberServiceImpl implements MemberService {
    @Value("${server.port}")
    private String serverPort;

    @Override
    public String getUser(Integer userId) {
        return "我是会员服务" + serverPort;
    }
}

service-impl-order编写openFeign客户端(直接实现会员服务接口即可):

package com.xyy.openfeign;

import com.xyy.MemberService;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;


@FeignClient("service-member")
public interface MemberServiceFeign extends MemberService {

}

  在service-impl-order编写订单实现:

package com.xyy.impl;

import com.xyy.openfeign.MemberServiceFeign;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class OrderService {
    @Autowired
    private MemberServiceFeign memberServiceFeign;
    /**
     * 基于我们的feign客户端形式实现rpc远程调用
     * @return
     */
    @RequestMapping("/orderFeignToMember")
    public String orderFeignToMember() {
        String result = memberServiceFeign.getUser(1);
        return "我是订单服务调用会员服务的接口,返回结果" + result;
    }
}

分别启动service-impl-member(8080),service-impl-member(8081),service-impl-order(8090),直接请求orderFeignToMember接口,会发现,底层默认封装了Ribbon进行客户端负载均衡:

SpringCloudAlibaba - RPC远程调用OpenFeign_第2张图片    

【小结】:

·  订单调会员的时候,会员服务接口的方法参数,一定要加@RequestParam注解,订单可以不用加。

·  在微服务架构中Nacos服务的名称命名不能够有下划线(service_order是错误写法,openfeign调用的时候报错)。

你可能感兴趣的:(OpenFeign,Ribbon,Nacos)