上一篇文章主要介绍了如何搭建一个简单的springcloud框架。不过,我们搭建好框架就是为了消费它使用它,那么这篇文章就来看看如何去消费使用我们之前搭建起来的服务吧!
首先本文是基于上一篇文章进行的。
Feign是Netflix开发的声明式、模板化的HTTP客户端, Feign可以帮助我们更快捷、优雅地调用HTTP API。
继续用上一节的工程, 启动eureka-server,端口为8080; 启动eureka-client两次,端口分别为8081 、8082.
我们首先要新建一个spring-boot工程,取名为serice-feign。
这次我们要选择三个依赖:
对应的pom.xml文件内容为:
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.5.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.zhouxiaoxi</groupId> <artifactId>eureka-feign</artifactId> <version>0.0.1-SNAPSHOT</version> <name>eureka-feign</name> <description>Demo project for Spring Boot</description> <properties> <java.version>1.8</java.version> <spring-cloud.version>Greenwich.SR1</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-netflix-eureka-client</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </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> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
接下来我们就需要配置application.yml文件了:
server: #端口号 port: 8083 spring: application: #端口名称 name: eureka-feign eureka: client: serviceUrl: #服务注册地址 defaultZone: http://localhost:8080/eureka/
在程序的启动类EurekaFeignApplication,加上@EnableFeignClients注解开启Feign的功能:
package com.zhouxiaoxi.eurekafeign; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.netflix.eureka.EnableEurekaClient; import org.springframework.cloud.openfeign.EnableFeignClients; @SpringBootApplication @EnableEurekaClient @EnableFeignClients public class EurekaFeignApplication { public static void main(String[] args) { SpringApplication.run(EurekaFeignApplication.class, args); } }
现在我们需要定义一个feign接口,通过@FeignClient(“服务名”)注解来指定调用哪个服务。
比如在下面的代码中调用了eureka-client服务的“/hello”接口,代码如下:
package com.zhouxiaoxi.eurekafeign.service; import org.springframework.cloud.openfeign.FeignClient; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; @FeignClient(value = "eureka-client") public interface SchedualServiceHello { @RequestMapping(value = "/hello",method = RequestMethod.GET) String sayHiFromClientOne(@RequestParam(value = "name") String name); }
在Web层的controller层,对外暴露一个”/hello”的API接口,通过上面定义的Feign客户端SchedualServiceHello 来消费服务。代码如下:
package com.zhouxiaoxi.eurekafeign.controller; import com.zhouxiaoxi.eurekafeign.service.SchedualServiceHello; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; @RestController public class HelloController { @Autowired SchedualServiceHello schedualServiceHello; @GetMapping(value = "/hello") public String sayHi(@RequestParam String name) { return schedualServiceHello.sayHiFromClientOne( name ); } }
启动程序,多次访问 http://localhost :8083/hello?name=feign,浏览器显示内容为:
hello feign ,i am from port:8081
hello feign ,i am from port:8082
至此我们这个服务消费的框架就搭建完毕了。。。