spring cloud学习(一) 服务注册

首先spring-cloud相关的简介能够去百度搜索，这里就很少说了，这里分享一个翻译spring cloud官网的中文网站spring cloud中文网

这个学习项目的代码放在 https://github.com/fengzp/SpringCloudDemo

1、建立eureka服务注册中心

1.1建立工程

我这里选的是spring-boot1.4.6的版本，由于暂时1.5.+的版本，spring-cloud会有一些bug

我这里的关于spring-cloud的学习都是在同一个项目下练习的。

最后根的pom文件以下

<?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.feng</groupId>
    <artifactId>spring-cloud</artifactId>
    <packaging>pom</packaging>
    <version>0.0.1</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>Camden.SR7</spring-cloud.version>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </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>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>
</project>

新建模块eureka-server
pom文件

<?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>spring-cloud</artifactId>
        <groupId>com.feng</groupId>
        <version>0.0.1</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>eureka-server</artifactId>

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

</project>

1.2
在resources下新建application.yml文件

server:
  port: 8010 #服务端口

eureka:
  instance:
    hostname: localhost
  client:
    register-with-eureka: false #是否将eureka自身做为应用注册到eureka注册中心
    fetch-registry: false #为true时，能够启动，但报异常：Cannot execute request on any known server
    serviceUrl:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

1.3
ServerApplication，使用@EnableEurekaServe标识这是一个eureka中心

package com.feng;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

/**
 * @author fengzp
 * @date 17/4/27
 * @email fengzp@gzyitop.com
 * @company 广州易站通计算机科技有限公司
 */
@SpringBootApplication
@EnableEurekaServer
public class ServerApplication {

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

运行成功后打开http://localhost:8010/

能够看到以下页面说明启动成功

2、新建服务提供者

2.1
新建模块service-a
pom文件

<?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>spring-cloud</artifactId>
        <groupId>com.feng</groupId>
        <version>0.0.1</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>service-a</artifactId>


</project>

2.2
新建配置文件application.yml
这里说明一点，端口能够使用${PORT:${SERVER_PORT:0}}来随机指定一个未使用的端口

spring:
  application:
    name: service-a

server:
  port: 8810

eureka:
  client:
    serviceUrl:
          defaultZone: http://localhost:8010/eureka/ #eureka服务注册地址

2.3
ServiceApplication：
使用@EnableDiscoveryClient来标识是一个eurekaclient

/**
 * @author fengzp
 * @date 17/4/27
 * @email fengzp@gzyitop.com
 * @company 广州易站通计算机科技有限公司
 */
@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class ServiceApplication {

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

    @Value("${spring.application.name}")
    private String name;
    @Value("${server.port}")
    private String port;

    @RequestMapping("/hi")
    public String hi(@RequestParam String id){
        return "hi, " + id + ", " + name + ":" + port;
    }

}

2.4
运行后再次打开http://localhost:8010/能够看到服务已经注册到中心