spring cloud

微服务：

大型系统架构中，会拆分多个子系统。简单来说，这些子系统有两个功能：提供接口、调用接口，在微服务架构中，将每一个这样的子系统称为一个“微服务”；

每一个服务会部署多个实例（就是多台机器，且会动态扩容，IP不固定）；
这种情况下，需要使用eureka进行服务管理。服务ID/名称 是唯一的标识， 接口调用前，根据ID在注册中心找到对应的实例信息(ip端口等)，然后再直调服务。

一、spring cloud服务注册中心

1、首先是pom文件，以下都是是使用spring cloud必须配置的内容。

<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>    <!-- spring boot 封装spring           starter封装、自动配置autoconfiguration     -->    <parent>        <groupId>org.springframework.cloud</groupId>        <artifactId>spring-cloud-starter-parent</artifactId>        <version>Dalston.SR1</version>        <relativePath />    </parent>    <groupId>com.dongnaoedu.springcloud</groupId><!-- 可以是自己的名称 -->    <artifactId>lession-1-eureka</artifactId><!-- 可以自定义id -->    <version>0.0.1-SNAPSHOT</version>    <dependencyManagement>        <dependencies>            <dependency>                <groupId>org.springframework.cloud</groupId>                <artifactId>spring-cloud-dependencies</artifactId>                <version>Dalston.SR1</version>                <type>pom</type>                <scope>import</scope>            </dependency>        </dependencies>    </dependencyManagement>    <dependencies>        <!-- spring-boot-starter-web web项目，集成容器tomcat -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>        <!-- spring-boot-starter-actuator 管理工具/web 查看堆栈，动态刷新配置 -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-actuator</artifactId>        </dependency>        <!-- cloud eureka组件 注册中心 -->        <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-eureka-server</artifactId>        </dependency>    </dependencies>    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>            </plugin>        </plugins>    </build></project>

2、配置bootstrap.yml

# 比application context先加载# 应用名称 项目运行后的名称spring:  application:    name: eureka-server

3、application.yml

# 上下文初始化加载info:  name: Eureka server  contact: 动脑科技VIPspring:  profiles:    active: dev---spring:  profiles: devserver:  port: 8761eureka:  client:    # 是否注册到eurekaserver    registerWithEureka: true    # 是否拉取信息    fetchRegistry: false    # eureka server地址    serviceUrl:      defaultZone: http://127.0.0.1:8761/eureka/  server:    waitTimeInMsWhenSyncEmpty: 0    # false 关闭自我保护，不管如何都要剔除心跳检测异常的服务    enableSelfPreservation: true    # updatePeerEurekaNodes执行间隔    peerEurekaNodesUpdateIntervalMs: 10000000  instance:    hostname: eureka1---spring:  profiles: eureka1server:  port: 8761eureka:  client:    registerWithEureka: true    fetchRegistry: true    serviceUrl:      defaultZone: http://eureka1:8761/eureka/,http://eureka2:8762/eureka/,http://eureka3:8763/eureka/  server:    waitTimeInMsWhenSyncEmpty: 0  instance:    hostname: eureka1    metadataMap:       instanceId: ${spring.application.name}:${vcap.application.instance_id:${spring.application.instance_id:${random.value}}}---spring:  profiles: eureka2server:  port: 8762eureka:  client:    registerWithEureka: true    fetchRegistry: true    serviceUrl:      defaultZone: http://eureka1:8761/eureka/,http://eureka2:8762/eureka/,http://eureka3:8763/eureka/  server:    waitTimeInMsWhenSyncEmpty: 0  instance:    hostname: eureka2    metadataMap:       instanceId: ${spring.application.name}:${vcap.application.instance_id:${spring.application.instance_id:${random.value}}}---spring:  profiles: eureka3server:  port: 8763eureka:  client:    registerWithEureka: true    fetchRegistry: true    serviceUrl:      defaultZone: http://eureka1:8761/eureka/,http://eureka2:8762/eureka/,http://eureka3:8763/eureka/  server:    waitTimeInMsWhenSyncEmpty: 0  instance:    hostname: eureka3    metadataMap:       instanceId: ${spring.application.name}:${vcap.application.instance_id:${spring.application.instance_id:${random.value}}}

4、启动类

服务启动类必须有两个注解
@SpringBootApplication//spring cloud是基于springboot的
@EnableEurekaServer//开启EurekaServer

package com.dongnaoedu.springcloud;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.builder.SpringApplicationBuilder;import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;@SpringBootApplication@EnableEurekaServer//开启EurekaServerpublic class EurekaApp {    public static void main(String[] args) {        new SpringApplicationBuilder(EurekaApp.class).web(true).run(args);    }}

5、启动查看信息

启动后进入：http://localhost:8761/ 可查看项目信息

信息解释：

二、服务提供者

1、pom文件

<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>    <!-- spring boot 封装spring           starter封装、自动配置autoconfiguration     -->    <parent>        <groupId>org.springframework.cloud</groupId>        <artifactId>spring-cloud-starter-parent</artifactId>        <version>Dalston.SR1</version>        <relativePath />    </parent>    <groupId>com.dongnaoedu.springcloud</groupId>    <artifactId>lession-1-sms-interface</artifactId>    <version>0.0.1-SNAPSHOT</version>    <dependencyManagement>        <dependencies>            <dependency>                <groupId>org.springframework.cloud</groupId>                <artifactId>spring-cloud-dependencies</artifactId>                <version>Dalston.SR1</version>                <type>pom</type>                <scope>import</scope>            </dependency>        </dependencies>    </dependencyManagement>    <dependencies>        <!-- spring-boot-starter-web web项目，集成容器tomcat -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>        <!-- spring-boot-starter-actuator 管理工具/web 查看堆栈，动态刷新配置 -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-actuator</artifactId>        </dependency>        <!-- cloud eureka组件 客户端 -->        <dependency>            <groupId>org.springframework.cloud</groupId>            <artifactId>spring-cloud-starter-eureka</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-data-jpa</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-data-rest</artifactId>        </dependency>        <dependency>            <groupId>org.hsqldb</groupId>            <artifactId>hsqldb</artifactId>            <scope>runtime</scope>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <scope>test</scope>        </dependency>    </dependencies>    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>            </plugin>        </plugins>    </build></project>

2、bootstrap.yml

# 比application先加载spring:  application:    name: lession-1-sms-interface

3、application.yml

# 上下文初始化加载info:  name: lession-1-sms-interface#端口server:  port: 9002# 配置eurekaeureka:  client:    registerWithEureka: true    fetchRegistry: true    # eureka server地址    serviceUrl:      defaultZone: http://127.0.0.1:8761/eureka/  instance:    # 心跳间隔    # properties中配置：eureka.instance.leaseRenewalIntervalInSeconds    leaseRenewalIntervalInSeconds: 30# 这个配置会被spring.application.instance_id覆盖（默认 hostname，appnane，port）#    metadataMap: #      instanceId: ${spring.application.name}:${spring.cloud.client.hostname}:${server.port}:${random.value}

4、启动类

package com.dongnaoedu.springcloud;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.builder.SpringApplicationBuilder;import org.springframework.cloud.netflix.eureka.EnableEurekaClient;// 服务提供者 - 短信接口@SpringBootApplication//springcloud是基于springboot的@EnableEurekaClient//Eureka客户端，用来获取信息public class SmsInterfaceApp {    public static void main(String[] args) {        new SpringApplicationBuilder(SmsInterfaceApp.class).web(true).run(args);    }}

5、control

package com.dongnaoedu.springcloud;import org.springframework.data.repository.PagingAndSortingRepository;import org.springframework.data.rest.core.annotation.RepositoryRestResource;// spring  data rest 技术@RepositoryRestResource(collectionResourceRel = "sms", path = "sms")public interface SmsController extends PagingAndSortingRepository<SmsDomain, Long> {}

6、bean

package com.dongnaoedu.springcloud;import java.io.Serializable;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.Table;@Entity@Table(name = "sms")public class SmsDomain implements Serializable {    private static final long serialVersionUID = -2485043500570220853L;    @Id    @GeneratedValue    private Long smsId;    @Column    private String phone;    @Column    private String content;    public Long getSmsId() {        return smsId;    }    public void setSmsId(Long smsId) {        this.smsId = smsId;    }    public String getPhone() {        return phone;    }    public void setPhone(String phone) {        this.phone = phone;    }    public String getContent() {        return content;    }    public void setContent(String content) {        this.content = content;    }}

三、服务消费者

消费者和提供者的pom文件和application和bootstrap还有启动类的代码都和服务提供者没什么区别，就不在贴出来了，想看的朋友可以下载源码查看。
消费者control：

package com.tony.springcloud;import java.io.IOException;import java.util.List;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.cloud.client.ServiceInstance;import org.springframework.cloud.client.discovery.DiscoveryClient;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import org.springframework.web.client.RestTemplate;@RestControllerpublic class TestController {    @Autowired    DiscoveryClient discoveryClient;// spring cloud 提供的客户端工具    @RequestMapping("test")    public String test() throws IOException{        // 调用服务器之前，通过eureka client 查询服务的实例信息        // 也就是说去看 部署了哪些机器，以及IP 端口等信息        List<ServiceInstance> instances = discoveryClient.getInstances("lession-1-sms-interface");        for (ServiceInstance serviceInstance : instances) {            System.out.println("获取到服务实例：" + serviceInstance.getPort());        }        // ribbon 客户端负载均衡        ServiceInstance serviceInstance = instances.get(0);        // 获取的IP  端口  信息        String host = serviceInstance.getHost();        int port = serviceInstance.getPort();        String result = new RestTemplate().getForObject("http://" + host + ":" + port +"/sms/1", String.class);        return result;    }}

四、功能操作

分别运行注册中心，服务提供者，服务消费者的启动类，然后用火狐的接口测试工具调用服务提供者的sms接口（http://localhost:9002/sms）保存信息：

然后调用服务消费者的“test”接口就可以访问到服务提供者的接口了：

通过这种方式就可以实现分布式，往深了学，这里还会涉及负载均衡，前后端分离也是用这个形式实现的。

注：源码链接http://download.csdn.net/download/w1lgy/10017378。