1、Mavn依賴:
<span style="white-space:pre"> </span><!-- dubbo begin -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>2.5.3</version>
<exclusions>
<exclusion>
<artifactId>spring</artifactId>
<groupId>org.springframework</groupId>
</exclusion>
</exclusions>
<scope>runtime</scope>
</dependency>
<!-- dubbo end -->
<!-- zookeeper begin -->
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.6</version>
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.101tec</groupId>
<artifactId>zkclient</artifactId>
<version>0.4</version>
</dependency>
<!-- zookeeper end -->
2、定義服務端提供方和消費方的通信接口
IDispatch.java
package com.gaojiasoft.test.dubbo;
//服務接口,dubbo服務的提供方及消費方都需要使用
public interface IDispatch
{
/**
* 有返回值,此時異步調用是收不到返回值的,需要在調用方增加回調接口獲取返回值。
* @param msg
* @return
*/
String dispatch(String msg);
/**
* 沒有返回值的,比較適合異步調用
* @param msg
*/
void noReturn(String msg);
}
3、在服務提供方實現具體的服務(在註銷代碼中,筆者視圖使用多線程來處理客戶端的請求,事實證明Dubbo中多此一舉,Dubbo是基於NIO的TCP通信,本身已經是線程池)
DispatchImpl.java
package com.gaojiasoft.test.dubbo.provider;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import org.apache.commons.lang3.concurrent.BasicThreadFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.gaojiasoft.test.dubbo.IDispatch;
public class DispatchImpl implements IDispatch {
public static final Logger log = LoggerFactory
.getLogger(DispatchImpl.class);
/**
*不需要使用多線程處理客戶端請求,因爲dubbo的服務端是NIO,內部含有多線程複用
*/
private static final ThreadPoolExecutor executor = new ThreadPoolExecutor(
50, 150, 30L, TimeUnit.SECONDS,
new LinkedBlockingQueue<Runnable>(),
new BasicThreadFactory.Builder().daemon(true)
.namingPattern("Dubbo-Provider-%d").build(),
new ThreadPoolExecutor.CallerRunsPolicy());
@Override
public String dispatch(final String msg) {
// String back = null;
// Future<Object> future = executor.submit(new Callable<Object>() {
// @Override
// public Object call() throws Exception {
//
// log.debug("Server1 get msg:"+msg);
// Thread.sleep(1);
// return "SERVER 1 retrun:" + msg;
//
// }
// });
// try {
// back = future.get().toString();
// } catch (InterruptedException | ExecutionException e) {
// e.printStackTrace();
// }
// return back;
log.debug("Server1 get msg:"+msg);
//Thread.sleep(1);
return "SERVER 1 retrun:" + msg;
}
@Override
public void noReturn(String msg) {
}
}
4、服務提供方的Spring配置
<?xml version="1.0" encoding="UTF-8"?>
<!-- dubbo服務提供方 -->
<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">
<!-- 提供方應用信息,用於計算依賴關係 -->
<dubbo:application name="Server-B" />
<!-- 使用zookeeper對外暴露服務 -->
<dubbo:registry protocol="zookeeper"
address="192.168.62.155:2181,192.168.62.153:2181,192.168.62.154:2181" />
<!-- 用dubbo協議在20880端口暴露服務 -->
<!-- 提供服務的線程池固定數量爲100,iothreads配置CPU個數+1 -->
<dubbo:protocol name="dubbo" port="20880" dispatcher="message"
threadpool="fixed" threads="100" iothreads="3" />
<!-- 聲明需要暴露的服務接口 及實現類-,版本號2.0.0,配置同樣版本號的消費者調用同樣版本號的生產者,executes="200"服務提供者線程池線程數,
loadbalance="leastactive"是負載服務端併發數量最小的,可選值random:隨機,roundrobin:輪詢,leastactive:最小併發 -->
<dubbo:service interface="com.gaojiasoft.test.dubbo.IDispatch"
ref="disPatchImpl" version="1.0.0" loadbalance="roundrobin" group="hs">
</dubbo:service>
<!-- 和本地bean一樣實現服務 -->
<bean id="disPatchImpl" class="com.gaojiasoft.test.dubbo.provider.DispatchImpl" />
</beans>
關於配置文件的介紹:
1、<dubbo:protocol>中的dispatcher可選擇
0. all 所有消息都派發到線程池,包括請求,響應,連接事件,斷開事件,心跳等。
1. direct 所有消息都不派發到線程池,全部在IO線程上直接執行。
2. message 只有請求響應消息派發到線程池,其它連接斷開事件,心跳等消息,直接在IO線程上執行。
3. execution 只請求消息派發到線程池,不含響應,響應和其它連接斷開事件,心跳等消息,直接在IO線程上執行。
4. connection 在IO線程上,將連接斷開事件放入隊列,有序逐個執行,其它消息派發到線程池。
2、<dubbo:server>中的group適用於多個系統都有同樣名稱的服務,此時,通過分組加以區分,此時消費方配置同樣名稱分組的就會調用同樣名稱的消費方。
3、<dubbo:server>中的version使用一個服務有多個版本,此時服務端提供多,可以提供多個名稱同樣的方法,使用不通的版本號。例如:
<dubbo:service interface="com.gaojiasoft.test.dubbo.IDispatch"
ref="<strong>disPatchImpl</strong>"<strong> version="1.0.0"</strong> loadbalance="roundrobin" group="hs">
</dubbo:service>
<dubbo:service interface="com.gaojiasoft.test.dubbo.IDispatch"
ref="<strong>disPatchImpl</strong>" <strong>version="2.0.0"</strong> loadbalance="roundrobin" group="hs">
</dubbo:service>
可以看到,服務名稱一致,版本號不一直的服務被同時暴露,此時客戶端按照自己的需求調用不同的版本號。就使得整個平臺的可擴展性大大加強,非常使用整個平臺的向下兼容的能力。
5、服務提供方的啓動類
DubboTest.java
package com.gaojiasoft.test.dubbo;
import java.io.IOException;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import org.apache.commons.lang3.concurrent.BasicThreadFactory;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class DubboTest {
private static ConfigurableApplicationContext contextProvider;
private static ConfigurableApplicationContext contextConsumer;
private Logger logger = LoggerFactory.getLogger("DubboTest");
private static final ThreadPoolExecutor executor = new ThreadPoolExecutor(
50, 150, 30L, TimeUnit.SECONDS,
new LinkedBlockingQueue<Runnable>(),
new BasicThreadFactory.Builder().daemon(true)
.namingPattern("Dubbo-Consumer-%d").build(),
new ThreadPoolExecutor.CallerRunsPolicy());
@Test
public void test() throws IOException, InterruptedException {
// String []list = new
// String[]{"classpath:conf/dubbo/spring-dubbo-provider.xml","classpath:conf/dubbo/spring-dubbo-consumer.xml"};
// contextProvider = new ClassPathXmlApplicationContext(list,true,null);
contextProvider = new ClassPathXmlApplicationContext(
"classpath:conf/dubbo/spring-dubbo-provider.xml");
while (true) {
Thread.sleep(1);
}
// contextConsumer = new ClassPathXmlApplicationContext(
// "classpath:conf/dubbo/spring-dubbo-consumer.xml");
//
// IDispatch service = (IDispatch) contextConsumer.getBean("disPatcher");
//
// int i = 1;
// while (true) {
// try {
// // 多線程消費
// mulitThreadConsumer(service, "" + i);
// } catch (Exception e) {
// logger.error("exception,dubbo provider error!");
// }
// Thread.sleep(1000);
// i++;
// }
}
/**
* 多線程消費者
*
* @param keyvalue
*/
private void mulitThreadConsumer(final IDispatch service,
final String message) {
executor.execute(new Runnable() {
@Override
public void run() {
try {
String revice = service.dispatch(message);
logger.debug("通過dubbo調用服務,返回的消息是:" + revice);
Thread.sleep(1);
} catch (Throwable th) {
// 防禦性容錯,避免高併發下的一些問題
logger.error("", th);
}
}
});
}
}
6、服務端消費方的Spring配置
<?xml version="1.0" encoding="UTF-8"?>
<!-- dubbo服務消費方 -->
<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">
<!-- 消費方應用信息,用於計算依賴關係,與提供方不要一樣 -->
<dubbo:application name="Server-A" />
<!-- 使用zookeeper註冊中心暴露服務地址 -->
<dubbo:registry protocol="zookeeper" address="192.168.62.155:2181,192.168.62.153:2181,192.168.62.154:2181" />
<!-- 生成遠程服務代理,與服務提供者建立3個TCP連接,並採用異步調用(非阻塞) -->
<dubbo:reference id="disPatcher" connections="3"
interface="com.gaojiasoft.test.dubbo.IDispatch" version="1.0.0" sent="false"
async="true" group="hs">
<!-- active是消費方請求線程池線程數,可針對不同的方法聲明不同的線程數-->
<dubbo:method name="dispatch" return="false" actives="50"></dubbo:method>
</dubbo:reference>
</beans>
7、服務消費方的啓動類
DubboConsumerStart.java
package com.study.dubbo.consumer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.gaojiasoft.test.dubbo.IDispatch;
public class DubboConsumerStart
{
public static final Logger log = LoggerFactory.getLogger(DubboConsumerStart.class);
public static void main(String[] args) throws Exception
{
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("conf/spring-dubbo-consumer.xml");
context.start();
IDispatch service = (IDispatch) context.getBean("dispatcher");
int i =1;
while(true)
{
try
{
String revice = service.dispatch(""+i);
log.debug("通過dubbo調用服務,返回的消息是:" + revice);
Thread.sleep(1);
i++;
}catch(Exception e)
{
log.debug("調用異常:" + e.getClass().getName());
}
}
// System.in.read(); //爲保證服務一直開着,利用輸入流的阻塞來模擬
}
}