Spring Cloud+Eureka+OpenFeign

项目结构

nemo-cloud

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>
    <packaging>pom</packaging>
    <modules>
        <module>my-client</module>
        <module>my-service</module>
        <module>eureka-service</module>
        <module>my-service-client</module>
    </modules>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.6</version>
        <relativePath/>
    </parent>

    <groupId>org.example</groupId>
    <artifactId>nemo-cloud</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <java.version>1.8</java.version>
        <spring-cloud.version>2021.0.1</spring-cloud.version>
    </properties>

    <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>

</project>

eureka-service

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">
  <parent>
    <artifactId>nemo-cloud</artifactId>
    <groupId>org.example</groupId>
    <version>1.0-SNAPSHOT</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  
  <artifactId>eureka-service</artifactId>
  
  <properties>
    <maven.compiler.source>8</maven.compiler.source>
    <maven.compiler.target>8</maven.compiler.target>
  </properties>
  
  <dependencies>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
  </dependencies>
  
</project>

EurekaServiceSpringBootApplication

@EnableEurekaServer
@SpringBootApplication
public class EurekaServiceSpringBootApplication {

    public static void main(String[] args) {
        SpringApplication.run(EurekaServiceSpringBootApplication.class, args);
    }

}

application.properties

spring.application.name=eureka-service

#服务注册中心端口号
server.port=8761
#服务注册中心实例的主机名
eureka.instance.hostname=localhost
#指向服务注册中心地址
eureka.client.serviceUrl.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/
#是否向服务注册中心注册自己
#eureka.client.register-with-eureka=false

my-service-client（公共类）

公共类，共享服务接口

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">
  <parent>
    <artifactId>nemo-cloud</artifactId>
    <groupId>org.example</groupId>
    <version>1.0-SNAPSHOT</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  
  <artifactId>my-service-client</artifactId>
  
  <properties>
    <maven.compiler.source>8</maven.compiler.source>
    <maven.compiler.target>8</maven.compiler.target>
  </properties>
  
  <dependencies>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
  </dependencies>
  
</project>

MyService

@FeignClient("my-service")
public interface MyService {

    @GetMapping("/getHostAddress")
    String getHostAddress();
}

my-service（服务提供者）

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">
    <parent>
        <artifactId>nemo-cloud</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>my-service</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </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.example</groupId>
            <artifactId>my-service-client</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

MyServiceSpringBootApplication

//启用服务注册客户端
@EnableDiscoveryClient
//spring boot启动注解
@SpringBootApplication
public class MyServiceSpringBootApplication {

    public static void main(String[] args) {
        SpringApplication.run(MyServiceSpringBootApplication.class, args);
    }

}

application.properties

spring.application.name=my-service
server.port=9001
#指向服务注册中心地址
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/

MyServiceImpl

@RestController
public class MyServiceImpl implements MyService{

    @RequestMapping("/getHostAddress")
    @Override
    public String getHostAddress() {
        try {
            InetAddress address = InetAddress.getLocalHost();
            return address.getHostAddress();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
        return null;
    }
}

my-client（服务调用者）

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">
    <parent>
        <artifactId>nemo-cloud</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>my-client</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </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.example</groupId>
            <artifactId>my-service-client</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
    </dependencies>

</project>

ClientController

@RestController
public class ClientController {

    @Autowired
    private DiscoveryClient discoveryClient;

    @Autowired
    private MyService myService;

    /**
     * 自己通过eureka获取服务端信息
     */
    @RequestMapping("/getUrl")
    public String getUrl(){
        //获取注册到eureka server实例列表
        List<ServiceInstance> instances = discoveryClient.getInstances("my-service");
        // 获取第一个服务信息
        ServiceInstance instanceInfo = instances.get(0);
        //获取ip
        String ip = instanceInfo.getHost();
        //获取port
        int port = instanceInfo.getPort();

        String url  ="http://"+ip+":"+port;

        return url;
    }

    /**
     * 通过openfeign调用服务端接口
     */
    @RequestMapping("/getHostAddress")
    public String getHostAddress(){
        return myService.getHostAddress();
    }

}

MyClientSpringBootApplication

//扫描包路径下的@FeignClient
@EnableFeignClients(basePackages = "com.service")
@EnableDiscoveryClient
@SpringBootApplication
public class MyClientSpringBootApplication {

    public static void main(String[] args) {
        SpringApplication.run(MyClientSpringBootApplication.class, args);
    }

}

application.properties

spring.application.name=my-client
server.port=8001
#指向服务注册中心地址
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/

测试

是否注册成功

测试通过eureka获取服务端信息

测试通过openfeign调用服务端接口