一、创建服务注册中心
1-1、建立maven主工程,主要引入spring-boot&spring-cloud通用依赖,之后的项目模块都会引入此项目依赖。
pom.xml 文件如下:
<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.leopard</groupId>
<artifactId>leopard-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<description>project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.6.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Dalston.SR5</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<!-- spring boot test-->
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</project>
1-2、建立一个简单maven工程作为服务注册中心,即Eureka Server,并依赖主工程
编辑pom.xml,加入服务中心依赖
<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.leopard</groupId>
<artifactId>leopard-eureka</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<parent>
<groupId>com.leopard</groupId>
<artifactId>leopard-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<dependencies>
<!--eureka server -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka-server</artifactId>
</dependency>
</dependencies>
</project>
编辑服务中心启动类,在主程序加入@EnableEurekaServer,并启动
package com.leopard.eureka;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@EnableEurekaServer
@SpringBootApplication
public class EurekaServiceApplication {
public static void main(String[] args) {
SpringApplication.run(EurekaServiceApplication.class, args);
}
}
1-3、eureka是一个高可用的组件,它没有后端缓存,每一个实例注册之后需要向注册中心发送心跳(因此可以在内存中完成),在默认情况下erureka server也是一个eureka client ,必须要指定一个 server。eureka server的配置文件application.yml
spring:
application:
name: eurka-server
server:
port: 8761
eureka:
instance:
hostname: localhost
server:
enableSelfPreservation: true
client:
register-with-eureka: false
fetch-registry: false
serviceUrl:
defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
registerWithEureka表示是否注册自身到eureka服务器
fetchRegistry表示是否从eureka服务器获取注册信息
通过registerWithEureka:false 和 fetchRegistry:false来表明自己是一个eureka server.
1-4、运行主程序,访问界面查看
二、创建一个服务提供者 (eureka client)
2-1、当client向server注册时,它会提供一些元数据,例如主机和端口,URL,主页等。Eureka server 从每个client实例接收心跳消息。 如果心跳超时,则通常将该实例从注册server中删除。
创建过程同server类似,创建完pom.xml如下:
<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.leopard</groupId>
<artifactId>leopard-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<groupId>com.leopard</groupId>
<artifactId>leopard-service</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>leopard-service</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<!-- eureka -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<!-- 上边引入 parent,因此 下边无需指定版本 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2-2、编辑启动类,并加入@EnableEurekaClient,声明为服务client 。
package com.leopard.service;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
@EnableEurekaClient
@SpringBootApplication
public class ServiceApplication {
public static void main(String[] args) {
SpringApplication.run(ServiceApplication.class, args);
}
}
仅仅@EnableEurekaClient是不够的,还需要在配置文件中注明自己的服务注册中心的地址,application.yml配置文件如下:
spring:
application:
name: leopard-service
server:
port: 8081
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/
需要指明spring.application.name,这个很重要,这在以后的服务与服务之间相互调用一般都是根据这个name 。
2-3、启动工程,打开http://localhost:8761 ,即eureka server 的网址:
你会发现一个服务已经注册在服务中了,服务名为LEOPARD-SERVICE ,端口为8081
2-4、创建一个测试类
package com.leopard.service.controller;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
/**
* 测试类
* @author leopard
*
*/
@RestController
@RequestMapping(value="/test")
public class TestController {
@Value("${server.port}")
private String port;
/**
* 获取信息
* @return
*/
@RequestMapping(value="/getObject" , method = RequestMethod.GET)
public String getObject(){
return "hi leopard,this port is :" + port;
}
/**
* 提交信息
* @return
*/
@RequestMapping(value="/postObject" , method = RequestMethod.POST)
public void postObject(){
//
}
/**
* 更新信息
* @return
*/
@RequestMapping(value="/putObject" , method = RequestMethod.PUT)
public void putObject(){
//
}
/**
* 删除信息
* @return
*/
@RequestMapping(value="/deleteObject" , method = RequestMethod.DELETE)
public void deleteObject(){
//
}
}
重新启动服务访问链接 : http://localhost:8081/test/getObject
输出如下:
hi leopard,this port is :8081
PS:这个client工程,后续文章会copy和迭代功能二次引用