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：
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>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
（2）修改配置
server.port=8010 spring.application.name=provider spring.cloud.consul.host=localhost spring.cloud.consul.port=8500 spring.cloud.consul.discovery.health-check-path=/actuator/health spring.cloud.consul.discovery.service-name=service-provider spring.cloud.consul.discovery.heartbeat.enabled=true management.endpoints.web.exposure.include=* management.endpoint.health.show-details=always
（3）测试方法
package com.xyz.provider.controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class demoController {
@RequestMapping("/hello")
public String Hello(){
return "hello,provider";
}
}
provider1
修改端口为8011
修改测试方法
package com.xyz.provider1.controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class demoController {
@RequestMapping("/hello")
public String Hello(){
return "hello,another provider";
}
}
启动provider和provider1
2.客户端
customer
（1）添加依赖
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.SR4</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
(2)配置
server.port=8015 spring.application.name=xyz-comsumer spring.cloud.consul.host=localhost spring.cloud.consul.port=8500 spring.cloud.consul.discovery.register=false spring.cloud.consul.discovery.health-check-url=/actuator/health spring.cloud.consul.discovery.heartbeat.enabled=true management.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
@SpringBootApplication
public 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;
@RestController
public 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
