Spring Cloud是一系列框架的有序集合。它利用Spring Boot的开发便利性巧妙地简化了分布式系统基础设施的开发,如服务发现注册、配置中心、消息总线、负载均衡、断路器、数据监控,都可以用Spring Boot的开发风格做到一键启动和部署。Spring Cloud并没有重复制造轮子,它只是将目前各家公司开发的比较成熟、经得起实际考验的服务框架组合起来,通过Spring Boot风格进行再封装屏蔽掉了复杂的配置和实现原理,最终给开发者留出了一套简单易懂、易部署和易维护的分布式系统开发工具包。
关于微服务相关文档可以点击此处查看。
常用组件
- 服务发现——Netflix Eureka
- 客服端负载均衡——Netflix Ribbon
- 断路器——Netflix Hystrix
- 服务网关——Netflix Zuul
- 分布式配置——Spring Cloud Config
在后续的学习中,会给大家继续介绍。
步骤
创建项目
项目结构如下,eureka-server外,在创建项目时选中Eureka Server 其余都应该为Eureka Discovery
pom文件配置
<?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>1.5.20.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.hph</groupId>
<artifactId>eureka-server</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>eureka-server</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Edgware.SR5</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</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>
在eureka-server中我们添加application.yml配置文件。
server:
port: 8761
eureka:
instance:
hostname: eureka-server # eureka实例的主机名
client:
register-with-eureka: false #不把自己注册到eureka上
fetch-registry: false #不从eureka上来获取服务的注册信息
service-url:
defaultZone: http://localhost:8761/eureka/
在EurekaServerApplication中我们添加@EnableEurekaServer 注解
package com.hph.eurek;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@EnableEurekaServer //添加
@SpringBootApplication
public class EurekaServerApplication {
public static void main(String[] args) {
SpringApplication.run(EurekaServerApplication.class, args);
}
}
启动项目
provider
下面我们来编写provider项目代码
pom文件配置如下
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.20.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.hph</groupId>
<artifactId>provider-ticket</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>provider-ticket</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Edgware.SR5</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</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>
创建服务
项目结构如图所使
package com.hph.provider.service;
import org.springframework.stereotype.Service;
@Service
public class TicketService {
public String getTicket(){
return "《复仇者联盟4:终局之战》";
}
配置视图控制器
package com.hph.provider.controller;
import com.hph.provider.service.TicketService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class TicketController {
@Autowired
TicketService ticketService;
@GetMapping("/ticket")
public String getTicket() {
return ticketService.getTicket();
}
}
编写配置文件
server:
port: 8001
spring:
application:
name: provider-ticket
eureka:
instance:
prefer-ip-address: true # 注册服务的时候使用服务的ip地址
client:
service-url:
defaultZone: http://localhost:8761/eureka/
启动服务
再去查看一下服务端
服务成功注册。
我们可以更换服务端口把它打成jar包实现多服务的注册测试。
consumer
consumer端项目结构如下
package com.hph.consumer;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@EnableDiscoveryClient //开启发现服务功能
@SpringBootApplication
public class ConsumerUserApplication {
public static void main(String[] args) {
SpringApplication.run(ConsumerUserApplication.class, args);
}
@LoadBalanced //使用负载均衡机制
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
}
package com.hph.consumer.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
@RestController
public class UserController {
@Autowired
RestTemplate restTemplate;
@GetMapping("/buy")
public String buyTicket(String name) {
//此参数为注册在Eureka中的服务
String ticketName = restTemplate.getForObject("http://PROVIDER-TICKET/ticket", String.class);
return name + "购买了" + ticketName;
}
}
启动后我们发现在Eureka上注册了另外一个服务
测试
我们访问consumer8200端口的buy方法。我们可以说这个服务时负载均衡的。它使用了轮询的方式。
后续会继续学习关于SpringClould的相关知识。