SpringCloud OpenFeign Demo

Myth丶恋晨 2023-01-08 04:26 158阅读 0赞

# 项目结构如下 #

![在这里插入图片描述][20210118233343249.png]  
其中API中主要放置了需要暴露的接口，service则通过`RequestMapping`的方式提供了一些`Controller`。在client中，通过feign的方式来调用这些controller。

# 主POM #

<?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>2.3.5.RELEASE</version>
            <relativePath/>
        </parent>
        <groupId>com.bxoon</groupId>
        <artifactId>demo-rpc</artifactId>
        <packaging>pom</packaging>
        <version>1.0-SNAPSHOT</version>
        <modules>
            <module>demo-rpc-api</module>
            <module>demo-rpc-service</module>
            <module>demo-rpc-client</module>
        </modules>
    
        <properties>
            <maven.compiler.source>8</maven.compiler.source>
            <maven.compiler.target>8</maven.compiler.target>
            <spring-cloud.version>Hoxton.SR8</spring-cloud.version>
            <spring-cloud-alibaba.version>2.2.3.RELEASE</spring-cloud-alibaba.version>
            <fastjson.version>1.2.75</fastjson.version>
        </properties>
    
        <dependencies>
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
            </dependency>
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>${fastjson.version}</version>
            </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>
                
                <dependency>
                    <groupId>com.alibaba.cloud</groupId>
                    <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                    <version>${spring-cloud-alibaba.version}</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
    
    </project>

# api 代码 #

pom

一个接口

@FeignClient(value = "demo-rpc-service")
    @Component
    public interface SayHello { 
        @GetMapping(value = "/sayHello")
        String sayHello();
    }

# service 代码 #

application.yml

server:
      port: 12080
    eureka:
      client:
        serviceUrl:
          defaultZone: http://${ EUREKA_HOST:192.168.7.135}:${ EUREKA_PORT:8761}/eureka/
    spring:
      application:
        name: demo-rpc-service

Controller

@RestController
    public class SayHelloController { 
        @GetMapping(value = "/sayHello")
        public String sayHello() { 
            return "hello";
        }
    }

# Client代码 #

pom

application.yml

server:
      port: 11080
    eureka:
      client:
        serviceUrl:
          defaultZone: http://${ EUREKA_HOST:192.168.7.135}:${ EUREKA_PORT:8761}/eureka/
    spring:
      application:
        name: demo-rpc-client

启动类需要加`@EnableFeignClients`注解

@EnableFeignClients(basePackages = { "com.bxoon"})
    @SpringBootApplication
    public class ClientApplication { 
        public static void main(String[] args) { 
            SpringApplication.run(ClientApplication.class, args);
        }
    }

Controller

@RestController
    @RequiredArgsConstructor
    public class SayHelloController { 
    
        private final SayHello sayHello;
    
        @RequestMapping("sayHello")
        String testSayHello(){ 
            return sayHello.sayHello();
        }
    }

# 测试 #

访问如下地址

> localhost:11080/sayHello

页面输出`hello`说明成功

# 其他 #

项目省略了`eureka`的部署过程，这个过程请自行百度。

[20210118233343249.png]: /images/20221119/b5309788990e4b2eaca5565ea2a9a26c.png