摘要：
xmlversion=“1.0”encoding=“UTF-8”？
此案例为替换原有的消费者，注册中心和消息提供者延用之前的
注册中心的案例 https://www.cnblogs.com/songlove/p/14793575.html
消息提供者：https://www.cnblogs.com/songlove/p/14794021.html
先创建一个工程，引用maven控制 ，比着之前的消费者的项目增加了一个feign的依赖
1 <dependency> 2 <groupId>org.springframework.cloud</groupId> 3 <artifactId>spring-cloud-starter-openfeign</artifactId> 4 </dependency>
第一步补全pom文件，完整的pom文件内容为
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> 4 <modelVersion>4.0.0</modelVersion> 5 <parent> 6 <groupId>org.springframework.boot</groupId> 7 <artifactId>spring-boot-starter-parent</artifactId> 8 <version>2.5.0</version> 9 <relativePath/> <!-- lookup parent from repository --> 10 </parent> 11 <groupId>com.ssc</groupId> 12 <artifactId>demo</artifactId> 13 <version>0.0.1-SNAPSHOT</version> 14 <name>demo</name> 15 <description>Demo project for Spring Boot</description> 16 <properties> 17 <java.version>1.8</java.version> 18 <spring-cloud.version>2020.0.3-SNAPSHOT</spring-cloud.version> 19 </properties> 20 <dependencies> 21 <dependency> 22 <groupId>org.springframework.boot</groupId> 23 <artifactId>spring-boot-starter-web</artifactId> 24 </dependency> 25 <dependency> 26 <groupId>org.springframework.cloud</groupId> 27 <artifactId>spring-cloud-starter-openfeign</artifactId> 28 </dependency> 29 <dependency> 30 <groupId>org.springframework.cloud</groupId> 31 <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> 32 </dependency> 33 <dependency> 34 <groupId>org.springframework.boot</groupId> 35 <artifactId>spring-boot-starter-test</artifactId> 36 <scope>test</scope> 37 </dependency> 38 </dependencies> 39 <dependencyManagement> 40 <dependencies> 41 <dependency> 42 <groupId>org.springframework.cloud</groupId> 43 <artifactId>spring-cloud-dependencies</artifactId> 44 <version>${spring-cloud.version}</version> 45 <type>pom</type> 46 <scope>import</scope> 47 </dependency> 48 </dependencies> 49 </dependencyManagement> 50 51 <build> 52 <plugins> 53 <plugin> 54 <groupId>org.springframework.boot</groupId> 55 <artifactId>spring-boot-maven-plugin</artifactId> 56 </plugin> 57 </plugins> 58 </build> 59 <repositories> 60 <repository> 61 <id>spring-snapshots</id> 62 <name>Spring Snapshots</name> 63 <url>https://repo.spring.io/snapshot</url> 64 <releases> 65 <enabled>false</enabled> 66 </releases> 67 </repository> 68 <repository> 69 <id>spring-milestones</id> 70 <name>Spring Milestones</name> 71 <url>https://repo.spring.io/milestone</url> 72 <snapshots> 73 <enabled>false</enabled> 74 </snapshots> 75 </repository> 76 </repositories> 77 78 </project>
第二步、在启动类上增加@EnableFeignClients和@EnableEurekaClient 注解，@EnableFeignClients注解是启用了feign客户端，如果Feign接口与启动类不是在同一个包下，需要增加包的扫描，@EnableFeignClients（basePackages=“com.ssc.demo”）
1 package com.ssc.demo; 2 3 import org.springframework.boot.SpringApplication; 4 import org.springframework.boot.autoconfigure.SpringBootApplication; 5 import org.springframework.cloud.netflix.eureka.EnableEurekaClient; 6 import org.springframework.cloud.openfeign.EnableFeignClients; 7 @EnableEurekaClient 8 @SpringBootApplication 9 @EnableFeignClients 10 public class DemoApplication { 11 12 public static void main(String[] args) { 13 SpringApplication.run(DemoApplication.class, args); 14 } 15 16 }
第三步，创建Feign接口
1 package com.ssc.demo; 2 3 import org.springframework.cloud.openfeign.FeignClient; 4 import org.springframework.web.bind.annotation.GetMapping; 5 import org.springframework.web.bind.annotation.RequestMapping; 6 import org.springframework.web.bind.annotation.RequestMethod; 7 //@FeignClient注解，这个注解标识当前是一个 Feign 的客户端，value 属性是对应的服务名称，也就是你需要调用哪个服务中的接口。 8 @FeignClient(value = "eureka-user-provide") 9 public interface UserRemoteClient { 10 //这个位置的请求路径就是，在这个提供者实例下提供具体服务的路径 11 @RequestMapping(value = "/user/hello",method = RequestMethod.GET) 12 String hello(); 13 }
第四步，写消费者调用类
package com.ssc.demo; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class CallHello { @Autowired private UserRemoteClient userRemoteClient; @GetMapping(value = "/callHello") public String calloHello(){ //此时的调用相当于 http://eureka-user-provide/user/hello String result=userRemoteClient.hello(); System.out.println("调用结果："+result); return result; } }
第五步，书写yml配置文件
1 server: 2 port: 8099 3 eureka: 4 client: 5 service-url: 6 defaultZone: http://localhost:8761/eureka 7 instance: 8 instance-id: ${spring.application.name}:${spring.cloud.client.ip-address}:${server.port} 9 spring: 10 application: 11 name: feign-user-consumer
第六步启动应用，调用接口。先查看eureka注册中心
输入请求路径，查看http://127.0.0.1:8099/callHello，成功调用
项目的gitee地址：Feign_demo: 创建一个feign案例 (gitee.com)