三个module:
service:定义接口
provider:定义接口实现
consumer:模拟接口调用
1:service
只是象征性的定义了一个接口:
package com.tch.test.dubbo.service; public interface DemoService { String sayHello(String name); }
2:provider:
pom.xml:
<dependency> <groupId>com.tch.test.dubbo</groupId> <artifactId>service</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>2.8.4</version> </dependency> <dependency> <groupId>com.101tec</groupId> <artifactId>zkclient</artifactId> <version>0.7</version> </dependency>
还有一个接口的简单实现:
package com.tch.test.dubbo.provider.serviceimpl; import com.tch.test.dubbo.service.DemoService; public class DemoServiceImpl implements DemoService { public String sayHello(String name) { return "Hello " + name; } }
然后是spring配置文件applicationContext.xml,里面保护了dubbo的配置,我这里使用到了本地localhost的zookeeper,端口是默认的2181,如果不用zookeeper的话,直接将
<dubbo:registry address="zookeeper://localhost:2181" check="false"></dubbo:registry>
这句话注释掉,将
<dubbo:registry address="multicast://224.5.6.7:1234" />
放开即可。至于为什么建议zookeeper部署奇数台,是因为根据zookeeper的leader选举算法,由于zookeeper挂掉一半的机器集群就不可用,所以部署4台和3台的集群都是在挂掉2台后集群不可用,所以使用奇数台机器,不浪费资源
:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd"> <!-- 提供方应用信息,用于计算依赖关系 --> <dubbo:application name="hello-world-app" /> <!-- 使用multicast广播注册中心暴露服务地址 --> <!-- <dubbo:registry address="multicast://224.5.6.7:1234" /> --> <dubbo:registry address="zookeeper://localhost:2181" check="false"></dubbo:registry> <!-- 用dubbo协议在20880端口暴露服务 --> <dubbo:protocol name="dubbo" port="20880" /> <!-- 声明需要暴露的服务接口 --> <dubbo:service interface="com.tch.test.dubbo.service.DemoService" ref="demoService" /> <!-- 和本地bean一样实现服务 --> <bean id="demoService" class="com.tch.test.dubbo.provider.serviceimpl.DemoServiceImpl" /> </beans>
然后是provider的测试类:
package com.tch.test.dubbo.provider.test; import org.springframework.context.support.ClassPathXmlApplicationContext; public class Provider { public static void main(String[] args) throws Exception { ClassPathXmlApplicationContext context = null; try { context = new ClassPathXmlApplicationContext(new String[] { "applicationContext.xml" }); context.start(); context.registerShutdownHook(); System.in.read(); } catch (Exception e) { e.printStackTrace(); }finally{ context.close(); } } }
3:consumer:
pom.xml和provider一样:
<dependency> <groupId>com.tch.test.dubbo</groupId> <artifactId>service</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>2.8.4</version> </dependency> <dependency> <groupId>com.101tec</groupId> <artifactId>zkclient</artifactId> <version>0.7</version> </dependency>
然后是spring配置文件applicationContext.xml:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd"> <!-- 消费方应用名,用于计算依赖关系,不是匹配条件,不要与提供方一样 --> <dubbo:application name="consumer-of-helloworld-app" /> <!-- 使用multicast广播注册中心暴露发现服务地址 --> <!-- <dubbo:registry address="multicast://224.5.6.7:1234" /> --> <dubbo:registry address="zookeeper://localhost:2181" check="false"></dubbo:registry> <!-- 生成远程服务代理,可以和本地bean一样使用demoService --> <dubbo:reference id="demoService" interface="com.tch.test.dubbo.service.DemoService" /> </beans>
最后是consumer的测试类:
package com.tch.test.dubbo.consumer.test; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.tch.test.dubbo.service.DemoService; public class Consumer { public static void main(String[] args) throws Exception { ClassPathXmlApplicationContext context = null; try { context = new ClassPathXmlApplicationContext(new String[] { "applicationContext.xml" }); context.start(); context.registerShutdownHook(); DemoService demoService = (DemoService) context.getBean("demoService"); // 获取远程服务代理 String hello = demoService.sayHello("world"); // 执行远程方法 System.out.println(hello); // 显示调用结果 context.stop(); } catch (Exception e) { e.printStackTrace(); }finally{ if(context != null){ context.close(); } } } }
接下来,先运行Provider.java,在运行Consumer.java即可看到调用结果(当前前提是zookeeper是启动的啦):
Hello world
添加依赖:
<dependency> <groupId>com.101tec</groupId> <artifactId>zkclient</artifactId> <version>0.7</version> </dependency>
一方面对zookeeper进行修改等操作,一方面进行监测:
package com.tch.zookeeper.test; import java.util.UUID; import org.I0Itec.zkclient.ZkClient; import org.apache.zookeeper.CreateMode; public class ZookeeperOperator { private ZkClient zkClient; public ZkClient getZkClient() { return zkClient; } public void setZkClient(ZkClient zkClient) { this.zkClient = zkClient; } /** * 函数入口 * @param args */ public static void main( String[] args ) { ZookeeperOperator bootStrap=new ZookeeperOperator(); bootStrap.initialize(); try { Thread.sleep(100000000); } catch (InterruptedException e) { e.printStackTrace(); } } /** * 初始化zookeeper */ public void initialize() { String connectionString="localhost:2181"; int connectionTimeout=50000; zkClient=new ZkClient(connectionString, connectionTimeout); if(!zkClient.exists("/root1")) { zkClient.create("/root1", new Long(System.currentTimeMillis()), CreateMode.EPHEMERAL); } new Thread(new RootNodeChangeThread()).start(); } /** * 每20s改变一次 'root1'节点的数据 * @author yang * */ private class RootNodeChangeThread implements Runnable{ public void run() { while(true) { try { Thread.sleep(2000); } catch (InterruptedException e) { //ignore } String uuidStr=UUID.randomUUID().toString(); System.out.println(">>>>>>>>>> 产生随机的 uuid string,'uuidStr'===>"+uuidStr); zkClient.writeData("/root1", uuidStr); } } } }
package com.tch.zookeeper.test.slave; import org.I0Itec.zkclient.IZkDataListener; import org.I0Itec.zkclient.ZkClient; public class ZookeeperMonitor { private ZkClient zkClient; public ZkClient getZkClient() { return zkClient; } public void setZkClient(ZkClient zkClient) { this.zkClient = zkClient; } /** * 初始化zookeeper */ public void initialize() { String connectionString="localhost:2181"; int connectionTimeout=500000; zkClient=new ZkClient(connectionString, connectionTimeout); new Thread(new Runnable() { public void run() { zkClient.subscribeDataChanges("/root1", new IZkDataListener() { public void handleDataDeleted(String dataPath) throws Exception { System.out.println("the node 'dataPath'===>"); } public void handleDataChange(String dataPath, Object data) throws Exception { System.out.println("the node 'dataPath'===>"+dataPath+", data has changed.it's data is "+String.valueOf(data)); } }); } }).start(); } /** * 函数入口 * @param args */ public static void main( String[] args ) { ZookeeperMonitor bootStrap=new ZookeeperMonitor(); bootStrap.initialize(); try { Thread.sleep(100000000); } catch (InterruptedException e) { e.printStackTrace(); } } }
通过运行结果即可明白