这篇文章主要介绍了spring boot2X Consul如何使用Feign实现服务调用,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

服务调用有两种方式：

　　A.使用RestTemplate 进行服务调用

　　B.使用Feign 进行声明式服务调用

上一次写了使用RestTemplate的方式，这次使用Feign的方式实现

服务注册发现中心使用Consul

启动Consul

consul agent -dev

spring boot 版本 2.2.1.RELEASE

1.服务端

provider

（1）添加依赖

<properties> <java.version>1.8</java.version> <spring-cloud.version>Greenwich.SR3</spring-cloud.version></properties><dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-consul-discovery</artifactId> </dependency></dependencies><dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring-cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies></dependencyManagement>

（2）修改配置

server.port=8010spring.application.name=providerspring.cloud.consul.host=localhostspring.cloud.consul.port=8500spring.cloud.consul.discovery.health-check-path=/actuator/healthspring.cloud.consul.discovery.service-name=service-providerspring.cloud.consul.discovery.heartbeat.enabled=truemanagement.endpoints.web.exposure.include=*management.endpoint.health.show-details=always

（3）测试方法

package com.xyz.provider.controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;@RestControllerpublic class demoController { @RequestMapping("/hello") public String Hello(){ return "hello,provider"; }}

provider1

修改端口为8011

修改测试方法

package com.xyz.provider1.controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;@RestControllerpublic class demoController { @RequestMapping("/hello") public String Hello(){ return "hello,another provider"; }}

启动provider和provider1

2.客户端

customer

（1）添加依赖

<properties> <java.version>1.8</java.version> <spring-cloud.version>Greenwich.SR4</spring-cloud.version></properties><dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-consul-discovery</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency></dependencies><dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring-cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies></dependencyManagement>

(2)配置

server.port=8015spring.application.name=xyz-comsumerspring.cloud.consul.host=localhostspring.cloud.consul.port=8500spring.cloud.consul.discovery.register=falsespring.cloud.consul.discovery.health-check-url=/actuator/healthspring.cloud.consul.discovery.heartbeat.enabled=truemanagement.endpoints.web.exposure.include=*management.endpoint.health.show-details=always

（3）修改启动类

添加注解 @EnableFeignClients，开启扫描Spring Cloud Feign客户端的功能

package com.xyz.comsumer;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.client.loadbalancer.LoadBalanced;import org.springframework.context.annotation.Bean;import org.springframework.web.client.RestTemplate;@EnableFeignClients@SpringBootApplicationpublic class ComsumerApplication { public static void main(String[] args) { SpringApplication.run(ComsumerApplication.class, args); }}

（4）添加Feign接口

添加注解@FeignClient(name = "provider")

provider是要调用的服务名

说明：

　　添加跟调用目标方法一样的方法声明，必须跟目标方法的定义一致

package com.xyz.consumer.controller;import org.springframework.cloud.openfeign.FeignClient;import org.springframework.web.bind.annotation.RequestMapping;@FeignClient(name = "provider")public interface ProviderService { @RequestMapping("/hello") public String hello();}

（4）服务调用

注入刚才声明的ProviderService，就可以像本地方法一样进行调用了

package com.xyz.consumer.controller;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;@RestControllerpublic class FeignController { @Autowired private ProviderService providerService; @RequestMapping("/call") public String call() { return providerService.hello(); }}

启动customer

访问http://localhost:8015/call

交替返回结果

hello,provider 或 hello,another provider

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。