Spring Cloud - 服务发现、注册、调用

• Spring Cloud - 服务发现、注册、调用（一）(eureka server)
• Spring Cloud - 服务发现、注册、调用（二）(eureka client(provider))
• Spring Cloud - 服务发现、注册、调用（三）(eureka client(consumer))

代码参见https://github.com/happut/springbootdemo

eureka client (provider)

既然有了服务注册的服务器，那么咱们就可以进行服务注册了，实际上服务注册服务器相当于一个中介，提供者将服务提供到注册服务器中，消费者只需要跟注册服务器打交道，不用硬编码具体的某个提供者。

建立springboot项目，增加spring-cloud-starter-eureka-server起步依赖：

<?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>

    <groupId>com.github.happut</groupId>
    <artifactId>springboot-demo-eureka-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springboot-demo-eureka-server</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.8.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>Edgware.RELEASE</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </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>


</project>

启动代码中增加@EnableEurekaClient

@SpringBootApplication
@EnableEurekaClient
public class SpringbootDemoEurekaProviderApplication {

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

application.properties(yml请注意缩进)

server.port=1112

spring.application.name=hello-service-provider

eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka

这里需要注意下端口不要和主服务器冲突，否则无法启动。

spring.application.name代表服务名称，前面说到，消费者无需硬编码接口服务器的ip、端口等，而需要依赖服务名称，这个等到搭建服务消费者的时候会提到。

eureka.client.serviceUrl.defaultZone务必要和主服务器一致，否则你也注册不上去啊。

在这里为了演示，我们临时写一个接口：

@RestController
public class HelloController {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());


    @RequestMapping("/hello")
    public String index() {
        return "ok";
    }
}

然后乐呵启动，我们可以简单测试下接口：

image.png

顺便看下主服务器中的变化：

image.png