简单易懂dubbo入门实例

一、创建Maven多模块项目

项目结构如下

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:

创建成功之后如下

把上面的src目录全部删除掉,只留下pom.xml

然后修改POM.XML如下成功如下:

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1. <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">  
2.   <modelVersion>4.0.0</modelVersion>  
3.   <groupId>com.fendo</groupId>  
4.   <artifactId>Dubbo_demos</artifactId>  
5.   <version>0.0.1-SNAPSHOT</version>  
6.   <packaging>pom</packaging>  
7.   <name>dubbo</name>  
8.   <description>dubbo示例</description>  
9.     
10.     
11.   <properties>  
12.     <maven.compiler.source>1.8</maven.compiler.source>  
13.     <maven.compiler.target>1.8</maven.compiler.target>  
14.     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
15.     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>  
16.       
17.     <!-- spring版本号 -->  
18.     <spring.version>4.2.5.RELEASE</spring.version>  
19.       
20.     <!-- log4j日志包版本号 -->  
21.     <slf4j.version>1.7.18</slf4j.version>  
22.     <log4j.version>1.2.17</log4j.version>  
23.       
24.    </properties>  
25.      
26.      
27.      
28.    <dependencyManagement>  
29.       <dependencies>  
30.           
31.         <!-- 添加junit4依赖 -->  
32.         <dependency>  
33.           <groupId>junit</groupId>  
34.           <artifactId>junit</artifactId>  
35.           <version>4.11</version>  
36.         </dependency>  
37.   
38.         <dependency>  
39.             <groupId>org.springframework</groupId>  
40.             <artifactId>spring-core</artifactId>  
41.             <version>${spring.version}</version>  
42.         </dependency>  
43.   
44.         <dependency>  
45.             <groupId>org.springframework</groupId>  
46.             <artifactId>spring-aop</artifactId>  
47.             <version>${spring.version}</version>  
48.         </dependency>  
49.         <dependency>  
50.             <groupId>org.springframework</groupId>  
51.             <artifactId>spring-context-support</artifactId>  
52.             <version>${spring.version}</version>  
53.         </dependency>  
54.   
55.      
56.         <!-- 添加日志相关jar包 -->  
57.         <dependency>  
58.           <groupId>log4j</groupId>  
59.           <artifactId>log4j</artifactId>  
60.           <version>${log4j.version}</version>  
61.         </dependency>  
62.         <dependency>  
63.           <groupId>org.slf4j</groupId>  
64.           <artifactId>slf4j-api</artifactId>  
65.           <version>${slf4j.version}</version>  
66.         </dependency>  
67.         <dependency>  
68.           <groupId>org.slf4j</groupId>  
69.           <artifactId>slf4j-log4j12</artifactId>  
70.           <version>${slf4j.version}</version>  
71.         </dependency>  
72.       
73.          <dependency>  
74.              <groupId>commons-logging</groupId>  
75.              <artifactId>commons-logging</artifactId>  
76.              <version>1.2</version>  
77.          </dependency>  
78.       
79.         <!-- dubbo -->  
80.         <dependency>  
81.           <groupId>com.alibaba</groupId>  
82.           <artifactId>dubbo</artifactId>  
83.           <version>2.5.3</version>  
84.           <exclusions>  
85.             <exclusion>  
86.               <groupId>org.springframework</groupId>  
87.               <artifactId>spring</artifactId>  
88.             </exclusion>  
89.           </exclusions>  
90.         </dependency>  
91.       
92.         <!-- Zookeeper zkclient-->  
93.         <dependency>  
94.             <groupId>com.github.sgroschupf</groupId>  
95.             <artifactId>zkclient</artifactId>  
96.             <version>0.1</version>  
97.         </dependency>  
98.       
99.    </dependencies>  
100.   </dependencyManagement>  
101.     
102.     
103. </project>  

 

(2)创建api项目

新建一个Module

输入module名,选择类型为java项目

点击"Finish",创建完成如下

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

(3)创建provider(生产者)

 

 

点击"Finish"生成如下

修改POM.XML为如下:

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1. <?xml version="1.0"?>  
2. <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"  
3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">  
4.   <modelVersion>4.0.0</modelVersion>  
5.     
6.   <parent>  
7.     <artifactId>Dubbo_demos</artifactId>  
8.     <groupId>com.fendo</groupId>  
9.     <version>0.0.1-SNAPSHOT</version>  
10.   </parent>  
11.     
12.   <groupId>com.fendo</groupId>  
13.   <artifactId>dubbo-provider</artifactId>  
14.   <version>0.0.1-SNAPSHOT</version>  
15.   <name>dubbo-provider</name>  
16.   <url>http://maven.apache.org</url>  
17.     
18.   <properties>  
19.     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
20.   </properties>  
21.     
22.     
23.   <dependencies>  
24.     
25.         <dependency>  
26.             <groupId>com.fendo</groupId>  
27.             <artifactId>dubbo-api</artifactId>  
28.             <version>0.0.1-SNAPSHOT</version>  
29.         </dependency>  
30.           
31.     
32.         <dependency>  
33.           <groupId>junit</groupId>  
34.           <artifactId>junit</artifactId>  
35.         </dependency>  
36.   
37.         <dependency>  
38.             <groupId>org.springframework</groupId>  
39.             <artifactId>spring-core</artifactId>  
40.         </dependency>  
41.   
42.         <dependency>  
43.             <groupId>org.springframework</groupId>  
44.             <artifactId>spring-aop</artifactId>  
45.         </dependency>  
46.           
47.         <dependency>  
48.             <groupId>org.springframework</groupId>  
49.             <artifactId>spring-context-support</artifactId>  
50.         </dependency>  
51.           
52.           
53.         <!-- 添加日志相关jar包 -->  
54.         <dependency>  
55.           <groupId>log4j</groupId>  
56.           <artifactId>log4j</artifactId>  
57.         </dependency>  
58.         <dependency>  
59.           <groupId>org.slf4j</groupId>  
60.           <artifactId>slf4j-api</artifactId>  
61.         </dependency>  
62.         <dependency>  
63.           <groupId>org.slf4j</groupId>  
64.           <artifactId>slf4j-log4j12</artifactId>  
65.         </dependency>  
66.       
67.          <!-- dubbo -->  
68.         <dependency>  
69.           <groupId>com.alibaba</groupId>  
70.           <artifactId>dubbo</artifactId>  
71.           <exclusions>  
72.             <exclusion>  
73.               <groupId>org.springframework</groupId>  
74.               <artifactId>spring</artifactId>  
75.             </exclusion>  
76.           </exclusions>  
77.         </dependency>  
78.       
79.         <!-- Zookeeper zkclient-->  
80.         <dependency>  
81.             <groupId>com.github.sgroschupf</groupId>  
82.             <artifactId>zkclient</artifactId>  
83.         </dependency>  
84.   </dependencies>  
85.     
86. </project>  

(4)创建consumer(消费者)

创建成如下

修改POM.XML为如下:

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1. <?xml version="1.0"?>  
2. <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"  
3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">  
4.   <modelVersion>4.0.0</modelVersion>  
5.     
6.     
7.   <parent>  
8.     <artifactId>Dubbo_demos</artifactId>  
9.     <groupId>com.fendo</groupId>  
10.     <version>0.0.1-SNAPSHOT</version>  
11.   </parent>  
12.     
13.   <groupId>com.fendo</groupId>  
14.   <artifactId>dubbo-consumer</artifactId>  
15.   <version>0.0.1-SNAPSHOT</version>  
16.   <name>dubbo-consumer</name>  
17.   <url>http://maven.apache.org</url>  
18.     
19.     
20.   <properties>  
21.     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>  
22.   </properties>  
23.     
24.     
25.   <dependencies>  
26.     
27.     <dependency>  
28.       <groupId>junit</groupId>  
29.       <artifactId>junit</artifactId>  
30.     </dependency>  
31.       
32.      <dependency>  
33.         <groupId>com.fendo</groupId>  
34.         <artifactId>dubbo-api</artifactId>  
35.         <version>0.0.1-SNAPSHOT</version>  
36.      </dependency>  
37.       
38.     <dependency>  
39.         <groupId>org.springframework</groupId>  
40.         <artifactId>spring-core</artifactId>  
41.     </dependency>  
42.   
43.     <dependency>  
44.         <groupId>org.springframework</groupId>  
45.         <artifactId>spring-aop</artifactId>  
46.     </dependency>  
47.       
48.     <dependency>  
49.         <groupId>org.springframework</groupId>  
50.         <artifactId>spring-context-support</artifactId>  
51.     </dependency>  
52.   
53.     <!-- dubbo -->  
54.     <dependency>  
55.       <groupId>com.alibaba</groupId>  
56.       <artifactId>dubbo</artifactId>  
57.       <exclusions>  
58.         <exclusion>  
59.           <groupId>org.springframework</groupId>  
60.           <artifactId>spring</artifactId>  
61.         </exclusion>  
62.       </exclusions>  
63.     </dependency>  
64.      
65.     <!-- Zookeeper zkclient-->  
66.     <dependency>  
67.         <groupId>com.github.sgroschupf</groupId>  
68.         <artifactId>zkclient</artifactId>  
69.     </dependency>  
70.       
71.   </dependencies>  
72. </project>  

创建完成后,整体结构如下

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

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

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

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1. public class DemoServiceImpl implements DemoService {  
2.   
3.     public List<String> getPermissions(Long id) {  
4.         List<String> demo = new ArrayList<String>();  
5.         demo.add(String.format("Permission_%d", id - 1));  
6.         demo.add(String.format("Permission_%d", id));  
7.         demo.add(String.format("Permission_%d", id + 1));  
8.         return demo;  
9.     }  
10.   
11.      
12. }  

以及消费者启动类Provider

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1. public class Provider {  
2.   
3.     public static void main(String[] args) throws IOException{  
4.           
5.         ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:provider.xml");  
6.         System.out.println(context.getDisplayName() + ": here");  
7.         context.start();  
8.         System.out.println("服务已经启动...");  
9.         System.in.read();  
10.     }  
11. }  

然后创建resources目录

在下新建两个xml文件

provider.xml是dubbo配置文件

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1. <?xml version="1.0" encoding="UTF-8"?>  
2. <beans xmlns="http://www.springframework.org/schema/beans"  
3.        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
4.        xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"  
5.        xsi:schemaLocation="http://www.springframework.org/schema/beans  
6.        http://www.springframework.org/schema/beans/spring-beans.xsd  
7.        http://code.alibabatech.com/schema/dubbo  
8.        http://code.alibabatech.com/schema/dubbo/dubbo.xsd">  
9.          
10.          
11.     <!--定义了提供方应用信息，用于计算依赖关系；在 dubbo-admin 或 dubbo-monitor 会显示这个名字，方便辨识-->  
12.     <dubbo:application name="demotest-provider" owner="programmer" organization="dubbox"/>  
13.     <!--使用 zookeeper 注册中心暴露服务，注意要先开启 zookeeper-->  
14.     <dubbo:registry address="zookeeper://localhost:2181"/>  
15.     <!-- 用dubbo协议在20880端口暴露服务 -->  
16.     <dubbo:protocol name="dubbo" port="20880" />  
17.     <!--使用 dubbo 协议实现定义好的 api.PermissionService 接口-->  
18.     <dubbo:service interface="com.fendo.dubbo.DemoService" ref="demoService" protocol="dubbo" />  
19.     <!--具体实现该接口的 bean-->  
20.     <bean id="demoService" class="org.dubbo.provider.impl.DemoServiceImpl"/>  
21. </beans>  

如果发现eclipse提示错误

解决方案,就是下载一个dubbo.xsd文件然后

windows->preferrence->xml->xmlcatalog 



add->catalog entry  ->file system 选择刚刚下载的文件路径



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

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

创建消费者运行类:

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1. public class Consumer   
2. {  
3.     public static void main(String[] args) {  
4.         //测试常规服务  
5.         ClassPathXmlApplicationContext context =  
6.                 new ClassPathXmlApplicationContext("consumer.xml");  
7.         context.start();  
8.         System.out.println("consumer start");  
9.         DemoService demoService = (DemoService) context.getBean(DemoService.class);  
10.         System.out.println("consumer");  
11.         System.out.println(demoService.getPermissions(1L));  
12.     }  
13. }  

consumer.xml配置文件为:

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1. <?xml version="1.0" encoding="UTF-8"?>  
2. <beans xmlns="http://www.springframework.org/schema/beans"  
3.        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
4.        xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"  
5.        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd  
6.        http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">  
7.       
8.     <dubbo:application name="demotest-consumer" owner="programmer" organization="dubbox"/>  
9.     <!--向 zookeeper 订阅 provider 的地址，由 zookeeper 定时推送-->  
10.     <dubbo:registry address="zookeeper://localhost:2181"/>  
11.     <!--使用 dubbo 协议调用定义好的 api.PermissionService 接口-->  
12.     <dubbo:reference id="permissionService" interface="org.dubbo.api.DemoService"/>  
13.       
14. </beans>  

五、使用zookeeper注册中心。

运行zookeeper/bin目录下的zkServer.cmd

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

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

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

会打印如上信息，表示消费成功!!!