上篇文章咱们写了service-user服务提供者,并使用ribbon的方式去调用,本次,咱们依然使用上一章节中的service-user做为服务提供者,改成使用feign去消费这个微服务java
feign客户端和ribbon 相似,一样实现了客户端的负载均衡,与ribbon不一样的是,feign的调用与本地接口的调用更加相似,而且更加便捷、更加优雅,传入参数较多时得以体现,固然,在实际项目中,二者可能都会用到,下面来写一下feign的实现web
选择Feign 和 Eureka Server点击完成 spring
pom.xml以下:apache
<?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> <groupId>com.mayi.springcloud</groupId> <artifactId>bussnessservice-user-client-feign</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>bussnessservice-user-client-feign</name> <description>用户中心服务调用者feign</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.1.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <spring-cloud.version>Finchley.M9</spring-cloud.version> </properties> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-server</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> <repositories> <repository> <id>spring-milestones</id> <name>Spring Milestones</name> <url>https://repo.spring.io/milestone</url> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories> </project>
bootstrap.ymlbootstrap
spring: application: name: service-user-client-feign server: port: 9001
在启动类添加@EnableFeignClients以启动feign客户端api
package com.mayi.springcloud; 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 BussnessserviceUserClientFeignApplication { public static void main(String[] args) { SpringApplication.run(BussnessserviceUserClientFeignApplication.class, args); } }
新建两个包:api 和 client 并建立相应的实现类微信
说明: UserFeignClient 是feign接口, UserFeignApi 是feign接口的调用者架构
UserFeignClient 代码以下:app
package com.mayi.springcloud.client; import org.springframework.cloud.openfeign.FeignClient; import org.springframework.web.bind.annotation.GetMapping; @FeignClient(name="service-user") public interface UserFeignClient { @GetMapping("/listUsers") public String listUsers(); }
解释:负载均衡
UserFeignApi 代码以下:
package com.mayi.springcloud.api; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import com.mayi.springcloud.client.UserFeignClient; @RestController public class UserFeignApi { @Autowired private UserFeignClient userFeignClient; @GetMapping("/listUsersByFeign") public String ListUsers(){ String users = this.userFeignClient.listUsers(); return users; } }
解释:
将刚才定义的userFeignClient注入,并当成普通的接口调用便可
启动两个service-user服务:端口分别为 8801 和 8802
访问:http://localhost:9001/listUsersByFeign
结果页面以下:
至此,feign的整合已完成,
下篇文章,咱们将要介绍配置中心的使用
接下来,我会依次更新文章,直至整个架构完成,若有兴趣的朋友关注做者 或 加我微信 拉你进入spring cloud社区群
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