dubbo的第一个入门的例子

男娘i 2022-06-01 10:18 228阅读 0赞

最近刚刚接触 Dubbo这个  框架，遇到了挺多的麻烦，网上搜索来的入门demo也是有挺多问题，百般周折终于弄出来了一个可以使用的小demo，与大家分享。

Zookeeper的介绍和安装：

本Demo中的Dubbo注册中心采用的是Zookeeper，为什么采用Zookeeper呢？

Zookeeper是一个分布式的服务框架，是树形的目录服务的数据存储，能做到集群管理数据，这里能很好的作为Dubbo服务的

注册中心。

Dubbo能与Zookeeper做到集群部署，当提供者出现断电等异常停机的时候。Zookeeper注册中心能自动的删除提供者的信息，

当提供者重启时，能自动恢复注册数据，以及订阅请求。

安装完成后，进入到 bin 目录中，并且启动，zkServer.cmd，这个脚本中会启动一个java进程：

(注:需要先启动zookeeper之后，后续dubbo demo代码运行才能使用 zookeeper注册中心的功能)

![SouthEast][]

2.开始创建我们的maven项目:

先创建一个dubbo-server的项目，项目的目录结构如下图所示:

![SouthEast 1][]

3.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.xbz</groupId>  
        <artifactId>dubbo-server</artifactId>  
        <version>0.0.1-SNAPSHOT</version>  
        <packaging>jar</packaging>  
      
        <name>server</name>  
        <url>http://maven.apache.org</url>  
      
        <properties>  
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
        </properties>  
      
        <dependencies>  
              
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-context</artifactId>  
                <version>4.1.6.RELEASE</version>  
            </dependency>  
              
      
              
            <dependency>  
                <groupId>com.alibaba</groupId>  
                <artifactId>dubbo</artifactId>  
                <version>2.5.3</version>  
            </dependency>  
              
      
              
            <dependency>  
                <groupId>org.apache.zookeeper</groupId>  
                <artifactId>zookeeper</artifactId>  
                <version>3.3.6</version>  
            </dependency>  
              
      
              
            <dependency>  
                <groupId>commons-logging</groupId>  
                <artifactId>commons-logging</artifactId>  
                <version>1.1.1</version>  
            </dependency>  
            <dependency>  
                <groupId>log4j</groupId>  
                <artifactId>log4j</artifactId>  
                <version>1.2.15</version>  
                <exclusions>  
                    <exclusion>  
                        <groupId>com.sun.jdmk</groupId>  
                        <artifactId>jmxtools</artifactId>  
                    </exclusion>  
                    <exclusion>  
                        <groupId>com.sun.jmx</groupId>  
                        <artifactId>jmxri</artifactId>  
                    </exclusion>  
                    <exclusion>  
                        <artifactId>jms</artifactId>  
                        <groupId>javax.jms</groupId>  
                    </exclusion>  
                    <exclusion>  
                        <artifactId>mail</artifactId>  
                        <groupId>javax.mail</groupId>  
                    </exclusion>  
                </exclusions>  
            </dependency>  
              
              
              
            <dependency>  
                <groupId>org.jboss.netty</groupId>  
                <artifactId>netty</artifactId>  
                <version>3.2.0.Final</version>  
            </dependency>  
            <dependency>  
                <groupId>com.101tec</groupId>  
                <artifactId>zkclient</artifactId>  
                <version>0.8</version>  
            </dependency>  
              
        </dependencies>  
    </project>

4.测试接口DemoService和实现类DemoServiceImpl

package com.xbz.service.impl;  
      
    import com.xbz.service.DemoService;  
      
    public class DemoServiceImpl implements DemoService {  
      
        public String sayHello(String name) {  
            System.out.println("init : " + name);  
            return "hello " + name;  
        }  
      
    }

package com.xbz.service;  
      
    public interface DemoService {  
      
        String sayHello(String name);  
      
    }

5.applicationProvider.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 ">  
        <dubbo:application name="dubbo-demo" />  
          
        <dubbo:registry address="zookeeper://127.0.0.1:2181" />  
        <dubbo:protocol name="dubbo" port="20880" />  
          
           
        <bean id="demoService" class="com.xbz.service.impl.DemoServiceImpl" />  
      
          
        <dubbo:service interface="com.xbz.service.DemoService"  
            ref="demoService" executes="10" />  
      
    </beans>

6.服务方主方法ServerMain

package main;  
      
    import java.io.IOException;  
      
    import org.springframework.context.support.ClassPathXmlApplicationContext;  
      
    public class ServerMain {  
      
        public static void main(String[] args) throws IOException {  
      
            ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext( new String[] { "applicationProvider.xml" });  
            context.start();  
      
            System.out.println("输入任意按键退出 ~ ");  
            System.in.read();  
            context.close();  
        }  
    }

至此，服务方就已经写成功了，接下来开始写客户端那一方，

在写客户端的那一方之前，首先，我们应该先把当前的这个项目放置到maven本地仓库中去，避免后面客户端在写的时候找不到接口从而报错。

方法是这样的：

右键 dubbo-server这个项目，run as --> run configuration —>Maven Build

![SouthEast 2][]

二、接下来开始写dubbo-client这个项目:

pom.xml文件如下(注意这个pom.xml文件在后面引入了 dubbo-server )：

<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.xbz</groupId>  
        <artifactId>dubbo-client</artifactId>  
        <version>0.0.1-SNAPSHOT</version>  
        <packaging>jar</packaging>  
      
        <name>client</name>  
        <url>http://maven.apache.org</url>  
      
        <properties>  
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
        </properties>  
      
        <dependencies>  
              
            <dependency>  
                <groupId>org.springframework</groupId>  
                <artifactId>spring-context</artifactId>  
                <version>4.1.6.RELEASE</version>  
            </dependency>  
              
      
              
            <dependency>  
                <groupId>com.alibaba</groupId>  
                <artifactId>dubbo</artifactId>  
                <version>2.5.3</version>  
            </dependency>  
              
      
              
            <dependency>  
                <groupId>org.apache.zookeeper</groupId>  
                <artifactId>zookeeper</artifactId>  
                <version>3.3.6</version>  
            </dependency>  
              
      
              
            <dependency>  
                <groupId>log4j</groupId>  
                <artifactId>log4j</artifactId>  
                <version>1.2.15</version>  
                <exclusions>  
                    <exclusion>  
                        <groupId>com.sun.jdmk</groupId>  
                        <artifactId>jmxtools</artifactId>  
                    </exclusion>  
                    <exclusion>  
                        <groupId>com.sun.jmx</groupId>  
                        <artifactId>jmxri</artifactId>  
                    </exclusion>  
                    <exclusion>  
                        <artifactId>jms</artifactId>  
                        <groupId>javax.jms</groupId>  
                    </exclusion>  
                    <exclusion>  
                        <artifactId>mail</artifactId>  
                        <groupId>javax.mail</groupId>  
                    </exclusion>  
                </exclusions>  
            </dependency>  
              
      
              
            <dependency>  
                <groupId>com.101tec</groupId>  
                <artifactId>zkclient</artifactId>  
                <version>0.8</version>  
            </dependency>  
            <dependency>  
                <groupId>com.xbz</groupId>  
                <artifactId>dubbo-server</artifactId>  
                <version>0.0.1-SNAPSHOT</version>  
            </dependency>  
              
        </dependencies>  
    </project>

2.消费端applicationConsumer.xml文件

<?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 ">  
        <dubbo:application name="dubbo-demo" />  
          
        <dubbo:registry address="zookeeper://127.0.0.1:2181" />  
        <dubbo:protocol name="dubbo" port="20880" />  
          
        
        <dubbo:application name="dubbo-client" owner="mic"/>
    
       
        
        <dubbo:reference id="demoService"
                         interface="com.xbz.service.DemoService"
                         protocol="dubbo"/>
    
      
    </beans>

3.客户端消费主方法clientMain

package main;  
      
    import org.springframework.context.support.ClassPathXmlApplicationContext;  
      
    import com.xbz.service.DemoService;  
      
    public class ClientMain {  
        public static void main(String[] args) {  
            ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(  
                    new String[] { "applicationConsumer.xml" });  
            context.start();  
            DemoService service = (DemoService) context.getBean("demoService");  
            System.out.println(service.sayHello("world"));  
            context.close();  
        }  
    }

client的项目结构如下：

![SouthEast 3][]

于是开始运行两边的主程序，启动服务方

![20160526161226431][]

运行客户端：

这时客户端输出的结果：

![SouthEast 4][]

服务器端输出的结果：

![SouthEast 5][]

进入dubbo-admin界面进行服务的管理。（首先我们应该先下载 dubbo-admin的包，可以在guthub上下载）

，然后将dubbo-admin这个包放入到tomcat中的 web-app目录下：随后启动Tomcat。

并且访问dubbo的管理菜单：(登录时候的用户名和密码初始化都是 root)

![SouthEast 6][]

[SouthEast]: /images/20220601/a58d9e534ffa49b5bd2fec3dd3710d86.png
[SouthEast 1]: /images/20220601/f6462187278344e48c302aaa293087c0.png
[SouthEast 2]: /images/20220601/6800520186684223be2146c2cd53f3cd.png
[SouthEast 3]: /images/20220601/159bcf85b4fa42a086feb91ae31c5ccb.png
[20160526161226431]: /images/20220601/3fbd3d045b1c4ae49f133d0ac3ee54a2.png
[SouthEast 4]: /images/20220601/c0b7b752f9664cb2a815439c53901a24.png
[SouthEast 5]: /images/20220601/c73d04dbc4d944399a4be79a9388d14a.png
[SouthEast 6]: /images/20220601/e28728926b7a4426b979485622e6e8c7.png