Dubbo快速入门

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前言

自学Dubbo框架，有不同见解的小伙伴可以一起交流：

跟随黑马视频学习Dubbo，如果有其他的不错的讲解视频或者是文档大家可以相互交流

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一、Dubbo概念

• Dubbo是阿里巴巴公司开源的一个高性能，轻量级的Java RPC框架
• 致力于提供高性能和透明化的RPC远程服务调用方案，以及SOA服务治理方案
• 官网： http://dubbo.apache.org
  

二、Dubbo快速入门案例

1.实现步骤

1. 创建服务提供者Provider模块
2. 创建服务消费者Consumer模块
3. 在服务提供者模块编写UserServiceImpl提供服务
4. 在服务消费者中的UserController远程调用UserServiceImpl提供的服务
5. 分别启动两个服务，测试

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2.创建Provider模块

1.创建一个Service实现类实现方法

注意：这个service注解一定要是dubbo提供的，而不是spring框架提供的service注解

import org.apache.dubbo.config.annotation.Service;

@Service//将这个类提供的方法（服务）对外发布。将访问的地址 ip，端口，路径注册到注册中心中
public class UserServiceImpl implements UserService {

    public String sayHello() {
        return "hello dubbo hello!~";
    }
}

2.创建配置文件

• 配置dubbo，配置项目的名称
• 配置注册中心的地址，我们使用zookeeper作为注册中心，就是配置zookeeper的地址
• 配置dubbo的包扫描

<beans xmlns="http://www.springframework.org/schema/beans"
	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	   xmlns:dubbo="http://dubbo.apache.org/schema/dubbo" xmlns:context="http://www.springframework.org/schema/context"
	   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">


	

	
	
	<dubbo:application name="dubbo-service"/>
	
	<dubbo:registry address="zookeeper://192.168.209.1**:2181"/>
	
	<dubbo:annotation package="com.itheima.service.impl" />

beans>

3.配置Web模块

因为我们要启动项目对外提供访问，所以需要配置web.xml

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://java.sun.com/xml/ns/javaee"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
         version="2.5">

		 
	
    <context-param>
        <param-name>contextConfigLocationparam-name>
        <param-value>classpath*:spring/applicationContext*.xmlparam-value>
    context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListenerlistener-class>
    listener>


web-app>

4.POM文件的引用

<packaging>warpackaging>
<dependencies>
        
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>javax.servlet-apiartifactId>
            <version>3.1.0version>
            <scope>providedscope>
        dependency>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-contextartifactId>
            <version>${spring.version}version>
        dependency>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-webmvcartifactId>
            <version>${spring.version}version>
        dependency>

        
        <dependency>
            <groupId>org.slf4jgroupId>
            <artifactId>slf4j-apiartifactId>
            <version>1.7.21version>
        dependency>
        <dependency>
            <groupId>org.slf4jgroupId>
            <artifactId>slf4j-log4j12artifactId>
            <version>1.7.21version>
        dependency>



        
        <dependency>
            <groupId>org.apache.dubbogroupId>
            <artifactId>dubboartifactId>
            <version>${dubbo.version}version>
        dependency>
        
        <dependency>
            <groupId>org.apache.curatorgroupId>
            <artifactId>curator-frameworkartifactId>
            <version>${zookeeper.version}version>
        dependency>
        
        <dependency>
            <groupId>org.apache.curatorgroupId>
            <artifactId>curator-recipesartifactId>
            <version>${zookeeper.version}version>
        dependency>


        
        <dependency>
            <groupId>com.itheimagroupId>
            <artifactId>dubbo-interfaceartifactId>
            <version>1.0-SNAPSHOTversion>
        dependency>

    dependencies>




    <build>
        <plugins>
            
            <plugin>
                <groupId>org.apache.tomcat.mavengroupId>
                <artifactId>tomcat7-maven-pluginartifactId>
                <version>2.1version>
                <configuration>
                    <port>9000port>
                    <path>/path>
                configuration>
            plugin>
        plugins>
    build>

3.创建Consumer

需要Reference这个注解，因为是远程调用，这个是dubbo提供的注解，不是本地调用，所以不能使用Autowired注解

1.创建一个消费者控制器

    /*
        1. 从zookeeper注册中心获取userService的访问url
        2. 进行远程调用RPC
        3. 将结果封装为一个代理对象。给变量赋值

     */

    @Reference//远程注入
    private UserService userService;


    @RequestMapping("/sayHello")
    public String sayHello(){
        return userService.sayHello();
    }

2.配置dubbo

跟provider中的配置一样

    
    
    <dubbo:application name="dubbo-web" >
        <dubbo:parameter key="qos.port" value="33333"/>
    dubbo:application>
    
    <dubbo:registry address="zookeeper://192.168.209.1**:2181"/>
    
    <dubbo:annotation package="com.itheima.controller" />

3.配置webapp

		 
    <servlet>
        <servlet-name>springmvcservlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
        
        <init-param>
            <param-name>contextConfigLocationparam-name>
            <param-value>classpath:spring/springmvc.xmlparam-value>
        init-param>
    servlet>

    <servlet-mapping>
        <servlet-name>springmvcservlet-name>
        <url-pattern>*.dourl-pattern>
    servlet-mapping>

4.Pom文件引用

 
        <dependency>
            <groupId>javax.servletgroupId>
            <artifactId>javax.servlet-apiartifactId>
            <version>3.1.0version>
            <scope>providedscope>
        dependency>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-contextartifactId>
            <version>${spring.version}version>
        dependency>
        
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-webmvcartifactId>
            <version>${spring.version}version>
        dependency>

        
        <dependency>
            <groupId>org.slf4jgroupId>
            <artifactId>slf4j-apiartifactId>
            <version>1.7.21version>
        dependency>
        <dependency>
            <groupId>org.slf4jgroupId>
            <artifactId>slf4j-log4j12artifactId>
            <version>1.7.21version>
        dependency>

        <dependency>
            <groupId>org.apache.dubbogroupId>
            <artifactId>dubboartifactId>
            <version>${dubbo.version}version>
        dependency>
        
        <dependency>
            <groupId>org.apache.curatorgroupId>
            <artifactId>curator-frameworkartifactId>
            <version>${zookeeper.version}version>
        dependency>
        
        <dependency>
            <groupId>org.apache.curatorgroupId>
            <artifactId>curator-recipesartifactId>
            <version>${zookeeper.version}version>
        dependency>

        
        <dependency>
            <groupId>com.itheimagroupId>
            <artifactId>dubbo-interfaceartifactId>
            <version>1.0-SNAPSHOTversion>
        dependency>

<build>
        <plugins>
            
            <plugin>
                <groupId>org.apache.tomcat.mavengroupId>
                <artifactId>tomcat7-maven-pluginartifactId>
                <version>2.1version>
                <configuration>
                    <port>8000port>
                    <path>/path>
                configuration>
            plugin>
        plugins>
    build>

总结

dubbo快速入门案例的实现，最好是把provider和consumer这两个项目实现的接口提取出去当作公共接口，实际生产项目也是这么做，一定要配置好Dubbo相关的配置工作和Web配置文件相关的操作