Dubbo教程(三)----一个简单的Dubbo示例

我就是我 2022-06-10 20:57 247阅读 0赞

**一、创建Maven多模块项目**

项目结构如下

![20170729180324856][]

模块介绍:

dubbo-api            ----API接口

dubbo-consumer ----消费者

dubbo-provider    ----生产者

dubbo-api  Service 提供的接口，provider 实现了 api 接口，并对外开放http端口，consumer依赖 api 工程，但是不会直接依赖provider工程。 这种可以让消费者仅仅依赖api工程，而不需要对provider工程的依赖，也是松耦合的经典。

(1)创建root项目

首先创建root项目,把一些通用的依赖全部放置到这里,步骤如下:

![20170729162325492][]

![20170729162334036][]

![20170729162454029][]

创建成功之后如下

![20170729162525394][]

把上面的src目录全部删除掉,只留下pom.xml

![20170729162620423][]

然后修改POM.XML如下成功如下:

<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.fendo</groupId>
      <artifactId>Dubbo_demos</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <packaging>pom</packaging>
      <name>dubbo</name>
      <description>dubbo示例</description>
      
      
      <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        
        
        <spring.version>4.2.5.RELEASE</spring.version>
        
        
        <slf4j.version>1.7.18</slf4j.version>
        <log4j.version>1.2.17</log4j.version>
        
       </properties>
       
       
       
       <dependencyManagement>
          <dependencies>
    	    
    	    
    	    <dependency>
    	      <groupId>junit</groupId>
    	      <artifactId>junit</artifactId>
    	      <version>4.11</version>
    	    </dependency>
    
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-core</artifactId>
    			<version>${spring.version}</version>
    		</dependency>
    
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-aop</artifactId>
    			<version>${spring.version}</version>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-context-support</artifactId>
    			<version>${spring.version}</version>
    		</dependency>
    
       
    	    
    	    <dependency>
    	      <groupId>log4j</groupId>
    	      <artifactId>log4j</artifactId>
    	      <version>${log4j.version}</version>
    	    </dependency>
    	    <dependency>
    	      <groupId>org.slf4j</groupId>
    	      <artifactId>slf4j-api</artifactId>
    	      <version>${slf4j.version}</version>
    	    </dependency>
    	    <dependency>
    	      <groupId>org.slf4j</groupId>
    	      <artifactId>slf4j-log4j12</artifactId>
    	      <version>${slf4j.version}</version>
    	    </dependency>
        
    	     <dependency>
    	         <groupId>commons-logging</groupId>
    	         <artifactId>commons-logging</artifactId>
    	         <version>1.2</version>
    	     </dependency>
        
    	    
    	    <dependency>
    	      <groupId>com.alibaba</groupId>
    	      <artifactId>dubbo</artifactId>
    	      <version>2.5.3</version>
    	      <exclusions>
    	        <exclusion>
    	          <groupId>org.springframework</groupId>
    	          <artifactId>spring</artifactId>
    	        </exclusion>
    	      </exclusions>
    	    </dependency>
        
        	
    		<dependency>
    		    <groupId>com.github.sgroschupf</groupId>
    		    <artifactId>zkclient</artifactId>
    		    <version>0.1</version>
    		</dependency>
        
       </dependencies>
      </dependencyManagement>
      
      
    </project>

(2)创建api项目

新建一个Module

![20170729162932074][]

输入module名,选择类型为java项目

![20170729163101974][]

![20170729163131567][]

点击"Finish",创建完成如下

![20170729165323868][]

他会自动在root目录下把dubbo-api这么module加入进来。而dubbo-api会自动继承root

![20170729165636686][]

(3)创建provider(生产者)

![20170729165854007][]

![20170729165915001][]

![20170729165934413][]

点击"Finish"生成如下

![20170729175026197][]

修改POM.XML为如下:

<?xml version="1.0"?>
    <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
      <modelVersion>4.0.0</modelVersion>
      
      <parent>
        <artifactId>Dubbo_demos</artifactId>
        <groupId>com.fendo</groupId>
        <version>0.0.1-SNAPSHOT</version>
      </parent>
      
      <groupId>com.fendo</groupId>
      <artifactId>dubbo-provider</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <name>dubbo-provider</name>
      <url>http://maven.apache.org</url>
      
      <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
      </properties>
      
      
      <dependencies>
      
      		<dependency>
    	    	<groupId>com.fendo</groupId>
    	    	<artifactId>dubbo-api</artifactId>
    	    	<version>0.0.1-SNAPSHOT</version>
            </dependency>
      		
      
    		<dependency>
    	      <groupId>junit</groupId>
    	      <artifactId>junit</artifactId>
    	    </dependency>
    
        	<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-core</artifactId>
    		</dependency>
    
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-aop</artifactId>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-context-support</artifactId>
    		</dependency>
    		
    		
    		
    	    <dependency>
    	      <groupId>log4j</groupId>
    	      <artifactId>log4j</artifactId>
    	    </dependency>
    	    <dependency>
    	      <groupId>org.slf4j</groupId>
    	      <artifactId>slf4j-api</artifactId>
    	    </dependency>
    	    <dependency>
    	      <groupId>org.slf4j</groupId>
    	      <artifactId>slf4j-log4j12</artifactId>
    	    </dependency>
        
    	     
    	    <dependency>
    	      <groupId>com.alibaba</groupId>
    	      <artifactId>dubbo</artifactId>
    	      <exclusions>
    	        <exclusion>
    	          <groupId>org.springframework</groupId>
    	          <artifactId>spring</artifactId>
    	        </exclusion>
    	      </exclusions>
    	    </dependency>
        
        	
    		<dependency>
    		    <groupId>com.github.sgroschupf</groupId>
    		    <artifactId>zkclient</artifactId>
    		</dependency>
      </dependencies>
      
    </project>

(4)创建consumer(消费者)

![20170729175356359][]

![20170729175428818][]

![20170729175454042][]

创建成如下

![20170729175805807][]

修改POM.XML为如下:

<?xml version="1.0"?>
    <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
      <modelVersion>4.0.0</modelVersion>
      
      
      <parent>
        <artifactId>Dubbo_demos</artifactId>
        <groupId>com.fendo</groupId>
        <version>0.0.1-SNAPSHOT</version>
      </parent>
      
      <groupId>com.fendo</groupId>
      <artifactId>dubbo-consumer</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <name>dubbo-consumer</name>
      <url>http://maven.apache.org</url>
      
      
      <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
      </properties>
      
      
      <dependencies>
      
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
        </dependency>
        
         <dependency>
        	<groupId>com.fendo</groupId>
        	<artifactId>dubbo-api</artifactId>
        	<version>0.0.1-SNAPSHOT</version>
         </dependency>
        
        <dependency>
    		<groupId>org.springframework</groupId>
    		<artifactId>spring-core</artifactId>
        </dependency>
    
    	<dependency>
    		<groupId>org.springframework</groupId>
    		<artifactId>spring-aop</artifactId>
    	</dependency>
    	
    	<dependency>
    		<groupId>org.springframework</groupId>
    		<artifactId>spring-context-support</artifactId>
    	</dependency>
    
        
        <dependency>
          <groupId>com.alibaba</groupId>
          <artifactId>dubbo</artifactId>
          <exclusions>
            <exclusion>
              <groupId>org.springframework</groupId>
              <artifactId>spring</artifactId>
            </exclusion>
          </exclusions>
        </dependency>
       
       	
    	<dependency>
    	    <groupId>com.github.sgroschupf</groupId>
    	    <artifactId>zkclient</artifactId>
    	</dependency>
        
      </dependencies>
    </project>

创建完成后,整体结构如下

![20170729175920826][]

这种结构看不起不是很美观,把它修改成如下显示,一个项目下包含多个子模块

![20170729180228123][]

**二、定义接口API、bo对象、公共类及方法，这些是要提供方和调用方都需要的。**

在dubbo-api模块中创建一个接口对外开发

![20170729181103308][]

**三、定义Dubbo服务service，实现dubbo-api中的api接口，书写业务逻辑及DB操作。通过spring暴露服务。**

创建DemoService实现类DemoServiceImpl

public class DemoServiceImpl implements DemoService {
    
        public List<String> getPermissions(Long id) {
            List<String> demo = new ArrayList<String>();
            demo.add(String.format("Permission_%d", id - 1));
            demo.add(String.format("Permission_%d", id));
            demo.add(String.format("Permission_%d", id + 1));
            return demo;
        }
    
       
    }

以及消费者启动类 Provider

public class Provider {
    
        public static void main(String[] args) throws IOException{
        	
            ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:provider.xml");
            System.out.println(context.getDisplayName() + ": here");
            context.start();
            System.out.println("服务已经启动...");
            System.in.read();
        }
    }

![20170729182754223][]

然后创建resources目录

![20170729182902195][]

在下新建两个xml文件

![20170729183003270][]

provider.xml是dubbo配置文件

<?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="demotest-provider" owner="programmer" organization="dubbox"/>
        
        <dubbo:registry address="zookeeper://localhost:2181"/>
        
        <dubbo:protocol name="dubbo" port="20880" />
        
        <dubbo:service interface="com.fendo.dubbo.DemoService" ref="demoService" protocol="dubbo" />
        
        <bean id="demoService" class="org.dubbo.provider.impl.DemoServiceImpl"/>
    </beans>

如果发现eclipse提示错误

![20170729183221431][]

解决方案,就是下载一个dubbo.xsd文件然后

windows->preferrence->xml->xmlcatalog   
  
![20170729183424735][]  
  
add->catalog entry  ->file system 选择刚刚下载的文件路径  
  
![20170729183505275][]  
  
修改key值和配置文件的http://code.alibabatech.com/schema/dubbo/dubbo.xsd 相同，点击OK之后就不会报错了。。

dubbo.xsd文件地址：[http://download.csdn.net/detail/u011781521/9914946][http_download.csdn.net_detail_u011781521_9914946]

**四、定义调用端也叫消费端，实现对应的控制层。通过spring获取服务。**

和上面差不多

![20170729184759337][]

创建消费者运行类:

public class Consumer 
    {
        public static void main(String[] args) {
            //测试常规服务
            ClassPathXmlApplicationContext context =
                    new ClassPathXmlApplicationContext("consumer.xml");
            context.start();
            System.out.println("consumer start");
            DemoService demoService = (DemoService) context.getBean(DemoService.class);
            System.out.println("consumer");
            System.out.println(demoService.getPermissions(1L));
        }
    }

consumer.xml配置文件为:

**五、使用zookeeper注册中心。**

运行zookeeper/bin目录下的zkServer.cmd

![20170729185050617][]

启动zookeeper

**六、启动Dubbo的service端，即provider。**

启动zookeeper之后,然后运行dubbo-provider中的Provider类

![20170729185225021][]

启动成功之后,如上所示,然后在dubbo-admin控制台会多出一个生产者

![20170729185416376][]

显示还没有消费者。。

**七、启动portal端，即所谓的consumer。**

然后启动dubbo-consumer中的Consumer类

![20170729185558121][]

会打印如上信息，表示消费成功!!!

完整示例: [http://download.csdn.net/detail/u011781521/9914955][http_download.csdn.net_detail_u011781521_9914955]

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[http_download.csdn.net_detail_u011781521_9914946]: http://download.csdn.net/detail/u011781521/9914946
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[http_download.csdn.net_detail_u011781521_9914955]: http://download.csdn.net/detail/u011781521/9914955