dubbo 快速入门

dubbo 是一个分布式服务框架，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。它采用全 Spring 配置方式，透明化接入应用，对应用没有任何API侵入，只需用 Spring 加载 dubbo 的配置即可。如需了解更多相关信息可前往官方文档用户指南部分的介绍。

1. 创建项目

创建一个 maven 多模块项目，结构如下：

dubbo-quickstart-sample（父模块）
|
|__ user-module-api（服务接口模块）
|
|__ user-module-provider（服务提供者）
|
|__ user-module-consumer（服务消费者）

1.1 父模块项目

dubbo-quickstart-sample/pom.xml 配置如下：

<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>org.fanlychie</groupId>
    <artifactId>dubbo-quickstart-sample</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>pom</packaging>
    <name>dubbo-quickstart-sample</name>
    <description>Sample project for Dubbo</description>
    <url>http://maven.apache.org</url>
    <modules>
        <module>user-module-api</module>
        <module>user-module-provider</module>
        <module>user-module-consumer</module>
    </modules>
    <properties>
        <dubbo.version>2.5.3</dubbo.version>
        <spring.version>4.3.7.RELEASE</spring.version>
    </properties>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.fanlychie</groupId>
                <artifactId>user-module-api</artifactId>
                <version>${project.version}</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>dubbo</artifactId>
                <!-- dubbo依赖的spring版本（2.5）较低, 排除此依赖, 使用自己的spring版本 -->
                <exclusions>
                    <exclusion>
                        <groupId>org.springframework</groupId>
                        <artifactId>spring</artifactId>
                    </exclusion>
                </exclusions>
                <version>${dubbo.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>${spring.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>${spring.version}</version>
            </dependency>
            <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
                <version>2.8.8</version>
            </dependency>
            <dependency>
                <groupId>com.101tec</groupId>
                <artifactId>zkclient</artifactId>
                <version>0.10</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

1.2 服务接口模块

user-module-api/pom.xml 配置如下：

<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.fanlychie</groupId>
        <artifactId>dubbo-quickstart-sample</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <artifactId>user-module-api</artifactId>
    <packaging>jar</packaging>
    <name>user-module-api</name>
    <url>http://maven.apache.org</url>
</project>

编写注册用户的示例服务接口：

package org.fanlychie.service;
    
public interface UserService {
    
    void register(String username, String password);
    
}

1.3 服务提供者

user-module-provider/pom.xml 配置如下：

<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.fanlychie</groupId>
        <artifactId>dubbo-quickstart-sample</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <artifactId>user-module-provider</artifactId>
    <packaging>jar</packaging>
    <name>user-module-provider</name>
    <url>http://maven.apache.org</url>
    <dependencies>
        <dependency>
            <groupId>org.fanlychie</groupId>
            <artifactId>user-module-api</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
        </dependency>
        <dependency>
            <groupId>com.101tec</groupId>
            <artifactId>zkclient</artifactId>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <!-- 打包配置, 输出可执行的 jar 包 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.6</version>
                <executions>
                    <execution>
                        <id>make-assembly</id>
                        <phase>package</phase>
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <archive>
                        <manifest>
                            <mainClass>com.alibaba.dubbo.container.Main</mainClass>
                        </manifest>
                    </archive>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

实现服务接口：

package org.fanlychie.service;
    
public class UserServiceImpl implements UserService {
    
    @Override
    public void register(String username, String password) {
        System.out.println("---------------------------------------------------------");
        System.out.println(String.format("接收到注册用户请求 - {username:%s, password:%s}",
                username, password));
        System.out.println("---------------------------------------------------------");
    }
    
}

user-module-provider/src/main/resources/dubbo.properties 配置如下：

# 服务容器
dubbo.container=spring
# 容器加载的 spring 配置文件
dubbo.spring.config=classpath:spring-dubbo-provider.xml

user-module-provider/src/main/resources/spring-dubbo-provider.xml 配置如下：

<?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">
    
    <!-- 提供方应用信息，用于计算依赖关系 -->
    <dubbo:application name="user-module-provider"/>
    
    <!-- 使用ZK注册中心暴露服务地址 -->
    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
    
    <!-- 用Dubbo协议在20880端口暴露服务 -->
    <dubbo:protocol name="dubbo" port="20880"/>
    
    <!-- 和本地Bean一样实现服务 -->
    <bean id="userService" class="org.fanlychie.service.UserServiceImpl"/>
    
    <!-- 声明需要暴露的服务接口 -->
    <dubbo:service interface="org.fanlychie.service.UserService" ref="userService"/>
    
</beans>

user-module-provider/src/main/resources/log4j.properties 配置如下：

log4j.rootCategory = INFO, console
log4j.appender.console = org.apache.log4j.ConsoleAppender
log4j.appender.console.target = System.out
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.conversionPattern = %d{yyyy-MM-dd HH:mm:ss:SSS} [%t] %-5p [%c{1}:%L] - %m%n

1.4 服务消费者

user-module-consumer/pom.xml 配置如下：

<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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.fanlychie</groupId>
        <artifactId>dubbo-quickstart-sample</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <artifactId>user-module-consumer</artifactId>
    <packaging>war</packaging>
    <name>user-module-consumer</name>
    <url>http://maven.apache.org</url>
    <dependencies>
        <dependency>
            <groupId>org.fanlychie</groupId>
            <artifactId>user-module-api</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
        <dependency>
            <groupId>com.101tec</groupId>
            <artifactId>zkclient</artifactId>
        </dependency>
    </dependencies>
    <build>
        <finalName>autosellrobot-wechat</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <configuration>
                    <path>/</path>
                    <port>8080</port>
                    <uriEncoding>UTF-8</uriEncoding>
                    <url>http://localhost:8080/manager/html</url>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

编写用户注册的服务方法：

@RestController
public class UserController {
    
    @Autowired
    private UserService userService;
    
    @GetMapping("/user/register")
    public String register(String username, String password) {
        if (!StringUtils.hasText(username) || !StringUtils.hasText(password)) {
            return "用户名或密码不能为空";
        }
        userService.register(username, password);
        return "注册完成";
    }
    
}

user-module-consumer/src/main/webapp/WEB-INF/web.xml 配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring-context.xml</param-value>
    </context-param>
    
    <listener>
        <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
    </listener>
    
    <listener>
        <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
    </listener>
    
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    
    <filter>
        <filter-name>encodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    
    <servlet>
        <servlet-name>dispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    
</web-app>

user-module-consumer/src/main/resources/spring-context.xml 配置如下：

<?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: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://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd">
    
    <context:annotation-config/>
    
    <context:component-scan base-package="org.fanlychie"/>
    
    <import resource="spring-dubbo-consumer.xml"/>
    
</beans>

user-module-consumer/src/main/resources/spring-dubbo-consumer.xml 配置如下：

<?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">
    
    <!-- 提供方应用信息，用于计算依赖关系 -->
    <dubbo:application name="user-module-consumer"/>
    
    <!-- 使用ZK注册中心暴露服务地址 -->
    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
    
    <!-- 生成远程服务代理，可以和本地Bean一样使用 -->
    <dubbo:reference id="userService" interface="org.fanlychie.service.UserService" />
    
</beans>

user-module-consumer/src/main/resources/spring-mvc.xml 配置如下：

<?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: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://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd">
    
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping">
        <property name="useSuffixPatternMatch" value="true"/>
        <property name="useTrailingSlashMatch" value="true"/>
    </bean>
    
    <bean id="stringHttpMessageConverter" class="org.springframework.http.converter.StringHttpMessageConverter">
        <constructor-arg value="UTF-8"/>
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=utf-8</value>
                <value>application/xml;charset=utf-8</value>
                <value>application/json;charset=utf-8</value>
            </list>
        </property>
    </bean>
    
    <bean id="mappingJackson2HttpMessageConverter"
          class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
        <property name="prefixJson" value="false"/>
        <property name="supportedMediaTypes">
            <list>
                <value>text/html;charset=utf-8</value>
                <value>application/xml;charset=utf-8</value>
                <value>application/json;charset=utf-8</value>
            </list>
        </property>
    </bean>
    
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="stringHttpMessageConverter"/>
                <ref bean="mappingJackson2HttpMessageConverter"/>
            </list>
        </property>
    </bean>
    
    <context:component-scan base-package="org.fanlychie.**.controller"/>
    
</beans>

user-module-consumer/src/main/resources/log4j.properties 配置如下：

log4j.rootCategory = INFO, console
log4j.appender.console = org.apache.log4j.ConsoleAppender
log4j.appender.console.target = System.out
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.conversionPattern = %d{yyyy-MM-dd HH:mm:ss:SSS} [%t] %-5p [%c{1}:%L] - %m%n

2. 启动服务

首先需要先启动 zookeeper 服务（可参考Zookeeper安装和配置），再启动 dubbo-admin 应用（可选，可参考dubbo-admin管理控制台应用安装）。

2.1 启动服务提供者

本示例将启用2个服务提供者的实例，并使用 dubbo 提供的com.alibaba.dubbo.container.Main启动类来启动服务提供者的实例。下面介绍3种较为常用的启动命令。

2.1.1 maven 命令启动

# 启动第一个实例, 端口 20881
> mvn exec:java -Ddubbo.protocol.port=20881 -Dexec.mainClass=com.alibaba.dubbo.container.Main
# 启动第二个实例, 端口 20882
> mvn exec:java -Ddubbo.protocol.port=20882 -Dexec.mainClass=com.alibaba.dubbo.container.Main

2.1.2 application 启动

以开发工具 IntelliJ IDEA 为例，Run -> Edit Configurations添加一个 Application，配置如下：

2.1.3 jar 包启动

在父模块项目 dubbo-quickstart-sample 根目录下执行打包命令：

> mvn package

执行完成之后，在 dubbo-quickstart-sample/user-module-provider/target 目录下将得到一个可执行的 jar 包：user-module-provider-0.0.1-SNAPSHOT.jar。

# 启动第一个实例, 端口 20881
> java -jar -Ddubbo.protocol.port=20881 user-module-provider-0.0.1-SNAPSHOT.jar
# 启动第二个实例, 端口 20882
> java -jar -Ddubbo.protocol.port=20882 user-module-provider-0.0.1-SNAPSHOT.jar

2.2 启动服务消费者

服务消费者 user-module-consumer 是一个 web 项目，使用内置 tomcat 容器或部署到外部的 tomcat 运行即可。

如使用内置 tomcat 插件启动的 maven 命令：

3. 访问服务

访问地址：http://localhost:8080/user/register?username=fanlychie&password=123456可在服务提供者的控制台查看相关的输出信息。你也可以在 dubbo-admin 应用查看和管理相关的服务：

示例项目开发环境：Java-8、Maven-3、IntelliJ IDEA-2017、Spring-4.7、Dubbo-2.5.3
完整示例项目链接：dubbo-quickstart-sample
参考文档文献链接：dubbo用户指南