1 简介
Spring Cloud支持两种方式远程调用
1.RestTemplate方式
2.Feign客户端工具，以后再实际开发中用的最多。
2.代码
springcloud_eureka 注册中心项目
springcloud_product 会员服务，也就是生产者
springcloud_feign_consumer 订单服务，也就是消费者
本项目结构是maven聚合项目
父模块依赖
<?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>2.0.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.fqyd</groupId>
<artifactId>springcloud</artifactId>
<version>1.0-SNAPSHOT</version>
<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.RELEASE</spring-cloud.version>
</properties>
<modules>
<module>springcloud_eureka</module>
<module>springcloud_eureka_ha</module>
<module>springcloud_product</module>
<module>springcloud_product_member</module>
<module>springcloud_consumer</module>
<module>springcloud_zk_member</module>
<module>springcloud_consul_member</module>
<module>springcloud_feign_consumer</module>
</modules>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<!-- Spring Cloud 管理依赖 -->
<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>2.1 springcloud_eureka 注册中心
引用以前的代码，这里就不重复编写
https://blog.csdn.net/qq_16855077/article/details/90752257
2.2 springcloud_product 消费提供者
引用以前的代码，这里就不重复编写
https://blog.csdn.net/qq_16855077/article/details/90770291
2.3 springcloud_feign_consumer 订单服务，也就是消费者
2.3.1 pom.xml
<?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>com.fqyd</groupId>
<artifactId>springcloud</artifactId>
<version>1.0-SNAPSHOT</version>
<relativePath>../pom.xml</relativePath>
</parent>
<groupId>com.fqyd</groupId>
<artifactId>springcloud_foreign_consumber</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springcloud_foreign_consumber</name>
<description>Demo project for Spring Boot</description>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!--feign依赖 配置-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<!--整合eureka-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
</dependencies>
</project>
注意：spring boot2.0以后，feign的依赖有变动spring-cloud-starter-openfeign，网上有不少是spring-cloud-starter-feign
2.3.2 application.yml
####订单服务器端口号
server:
port: 8001
###服务别名---服务器注册到注册中心的名称
spring:
application:
name: feign-order
eureka:
client:
###当前服务注册到eureka服务地址
serviceUrl:
defaultZone: http://localhost:8100/eureka/
2.3.3 controller
package com.fqyd.api.controller;
import com.fqyd.feign.MemberApiFeign;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* Description：
* Author: wude
* Date: 2019/7/23 16:42
* Modified By:
*/
@RestController
public class FeignController {
@Autowired
private MemberApiFeign memberApiFeign;
@RequestMapping("/feignMember")
public String feignMember(){
return memberApiFeign.getMember();
};
}
2.3.4 MemberApiFeign
package com.fqyd.feign;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
/**
* Description：
* Author: wude
* Date: 2019/7/23 16:11
* Modified By:
*/
@FeignClient(name = "fqyd-member")
public interface MemberApiFeign {
//FeignClient 调用服务接口
@RequestMapping("getMember")
public String getMember();
}
这里的业务逻辑是订单服务调用会员服务
会员服务---消息提供者
订单服务---消费者
注意：谁是消费者，这部分代码就写在哪里，fqyd-member是会员服务注册在eureka上的别名
2.3.5 启动类
package com.fqyd;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class SpringcloudFeignConsumberApplication {
public static void main(String[] args) {
SpringApplication.run(SpringcloudFeignConsumberApplication.class, args);
}
}
比以前的代码多引入勒一个注解@EnableFeignClients
3 测试
分别启动注册中心，消息提供者，消费者
http://localhost:8001/feignMember
feign实现远程调用，实际上就是http调用，等价于httpclient
