dubbo入门学习(二)-----dubbo hello world

一、dubbo hello world入门示例

1、提出需求

某个电商系统，订单服务需要调用用户服务获取某个用户的所有地址；

我们现在需要创建两个服务模块进行测试：

模块	功能
订单服务web模块	创建订单等
用户服务service模块	查询用户地址等

测试预期结果：订单服务web模块在A服务器，用户服务模块在B服务器，A可以远程调用B的功能。

2、工程结构

根据 dubbo《服务化最佳实践》

a、分包

建议将服务接口，服务模型，服务异常等均放在 API 包中，因为服务模型及异常也是 API 的一部分，同时，这样做也符合分包原则：重用发布等价原则(REP)，共同重用原则(CRP)。
如果需要，也可以考虑在 API 包中放置一份 spring 的引用配置，这样使用方，只需在 spring 加载过程中引用此配置即可，配置建议放在模块的包目录下，以免冲突，如：com/alibaba/china/xxx/dubbo-reference.xml。

b、粒度

服务接口尽可能大粒度，每个服务方法应代表一个功能，而不是某功能的一个步骤，否则将面临分布式事务问题，Dubbo 暂未提供分布式事务支持。服务接口建议以业务场景为单位划分，并对相近业务做抽象，防止接口数量爆炸。
不建议使用过于抽象的通用接口，如：Map query(Map)，这样的接口没有明确语义，会给后期维护带来不便。

二、创建工程

1、创建project、module

本demo采用project以及多module的方式，project叫dubbo，module分别为gmall-interface、order-service-consumer、user-service-providor，如图：

a、父project

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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.ty</groupId>
    <artifactId>dubbo</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>gmall-interface</module>
        <module>order-service-consumer</module>
        <module>user-service-providor</module>
    </modules>

    <!--如果不指定可能会报一个错误，@Override is not allowed when implementing interface method-->
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

b、公共接口层(gmall-interface)

结构如图：

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <parent>
        <artifactId>dubbo</artifactId>
        <groupId>com.ty</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>gmall-interface</artifactId>

</project>

UserAddress

package com.ty.bean;

import java.io.Serializable;

/**
 * 用户地址
 * @author lfy
 *
 */
public class UserAddress implements Serializable {

    private Integer id;
    private String userAddress; //用户地址
    private String userId; //用户id
    private String consignee; //收货人
    private String phoneNum; //电话号码
    private String isDefault; //是否为默认地址    Y-是     N-否

    public UserAddress() {
        super();
        // TODO Auto-generated constructor stub
    }

    public UserAddress(Integer id, String userAddress, String userId, String consignee, String phoneNum,
                       String isDefault) {
        super();
        this.id = id;
        this.userAddress = userAddress;
        this.userId = userId;
        this.consignee = consignee;
        this.phoneNum = phoneNum;
        this.isDefault = isDefault;
    }

    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getUserAddress() {
        return userAddress;
    }
    public void setUserAddress(String userAddress) {
        this.userAddress = userAddress;
    }
    public String getUserId() {
        return userId;
    }
    public void setUserId(String userId) {
        this.userId = userId;
    }
    public String getConsignee() {
        return consignee;
    }
    public void setConsignee(String consignee) {
        this.consignee = consignee;
    }
    public String getPhoneNum() {
        return phoneNum;
    }
    public void setPhoneNum(String phoneNum) {
        this.phoneNum = phoneNum;
    }
    public String getIsDefault() {
        return isDefault;
    }
    public void setIsDefault(String isDefault) {
        this.isDefault = isDefault;
    }

}

OrderService

package com.ty.service;

import com.ty.bean.UserAddress;

import java.util.List;

public interface OrderService {

    /**
     * 初始化订单
     * @param userId
     */
    public List<UserAddress> initOrder(String userId);

}

UserService

package com.ty.service;

import com.ty.bean.UserAddress;

import java.util.List;

/**
 * 用户服务
 * @author lfy
 *
 */
public interface UserService {

    /**
     * 按照用户id返回所有的收货地址
     * @param userId
     * @return
     */
    public List<UserAddress> getUserAddressList(String userId);

}

c、user-service-providor

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <parent>
        <artifactId>dubbo</artifactId>
        <groupId>com.ty</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>user-service-providor</artifactId>

    <dependencies>
        <dependency>
            <groupId>com.ty</groupId>
            <artifactId>gmall-interface</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <!-- 引入dubbo -->
        <!-- https://mvnrepository.com/artifact/com.alibaba/dubbo -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.6.2</version>
        </dependency>
        <!-- 注册中心使用的是zookeeper，引入操作zookeeper的客户端端 -->
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-framework</artifactId>
            <version>2.12.0</version>
        </dependency>

    </dependencies>
</project>

UserServiceImpl

package com.ty.service.impl;

import com.ty.bean.UserAddress;
import com.ty.service.UserService;

import java.util.Arrays;
import java.util.List;

public class UserServiceImpl implements UserService {

    @Override
    public List<UserAddress> getUserAddressList(String userId) {
        System.out.println("UserServiceImpl.....old...");
        // TODO Auto-generated method stub
        UserAddress address1 = new UserAddress(1, "北京市昌平区宏福科技园综合楼3层", "1", "李老师", "010-56253825", "Y");
        UserAddress address2 = new UserAddress(2, "深圳市宝安区西部硅谷大厦B座3层（深圳分校）", "1", "王老师", "010-56253825", "N");
        /*try {
            Thread.sleep(4000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }*/
        return Arrays.asList(address1,address2);
    }

}

UserServiceImpl2

package com.ty.service.impl;

import com.ty.bean.UserAddress;
import com.ty.service.UserService;

import java.util.Arrays;
import java.util.List;

public class UserServiceImpl2 implements UserService {

    @Override
    public List<UserAddress> getUserAddressList(String userId) {
        System.out.println("UserServiceImpl.....new...");
        // TODO Auto-generated method stub
        UserAddress address1 = new UserAddress(1, "北京市昌平区宏福科技园综合楼3层", "1", "李老师", "010-56253825", "Y");
        UserAddress address2 = new UserAddress(2, "深圳市宝安区西部硅谷大厦B座3层（深圳分校）", "1", "王老师", "010-56253825", "N");

        return Arrays.asList(address1,address2);
    }

}

UserServiceStub

package com.ty.service.impl;

import com.ty.bean.UserAddress;
import com.ty.service.UserService;
import org.springframework.util.StringUtils;

import java.util.List;

public class UserServiceStub implements UserService {

    private final UserService userService;

    /**
     * 传入的是userService远程的代理对象
     * @param userService
     */
    public UserServiceStub(UserService userService) {
        super();
        this.userService = userService;
    }

    @Override
    public List<UserAddress> getUserAddressList(String userId) {
        // TODO Auto-generated method stub
        System.out.println("UserServiceStub.....");
        if(!StringUtils.isEmpty(userId)) {
            return userService.getUserAddressList(userId);
        }
        return null;
    }

}

MainApplication

package com.ty;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;

public class MainApplication {

    public static void main(String[] args) throws IOException {
        ClassPathXmlApplicationContext ioc = new ClassPathXmlApplicationContext("provider.xml");
        ioc.start();

        System.in.read();
    }

}

providor.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://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd
        http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">

    <!-- 1、指定当前服务/应用的名字（同样的服务名字相同，不要和别的服务同名） -->
    <dubbo:application name="user-service-provider"></dubbo:application>

    <!-- 2、指定注册中心的位置 -->
    <!-- <dubbo:registry address="zookeeper://127.0.0.1:2181"></dubbo:registry> -->
    <dubbo:registry protocol="zookeeper" address="127.0.0.1:2181"></dubbo:registry>

    <!-- 3、指定通信规则（通信协议？通信端口） -->
    <dubbo:protocol name="dubbo" port="20882"></dubbo:protocol>

    <!-- 4、暴露服务   ref：指向服务的真正的实现对象 -->
    <dubbo:service interface="com.ty.service.UserService"
        ref="userServiceImpl01" timeout="1000" version="1.0.0">
        <dubbo:method name="getUserAddressList" timeout="1000"></dubbo:method>
    </dubbo:service>

    <!--统一设置服务提供方的规则  -->
    <dubbo:provider timeout="1000"></dubbo:provider>

    <!-- 服务的实现 -->
    <bean id="userServiceImpl01" class="com.ty.service.impl.UserServiceImpl"></bean>

    <dubbo:service interface="com.ty.service.UserService"
        ref="userServiceImpl02" timeout="1000" version="2.0.0">
        <dubbo:method name="getUserAddressList" timeout="1000"></dubbo:method>
    </dubbo:service>
    <bean id="userServiceImpl02" class="com.ty.service.impl.UserServiceImpl2"></bean>

    <!-- 连接监控中心 -->
    <dubbo:monitor protocol="registry"></dubbo:monitor>

</beans>

d、order-service-consumer

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <parent>
        <artifactId>dubbo</artifactId>
        <groupId>com.ty</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>order-service-consumer</artifactId>

    <dependencies>
        <dependency>
            <groupId>com.ty</groupId>
            <artifactId>gmall-interface</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!-- 引入dubbo -->
        <!-- https://mvnrepository.com/artifact/com.alibaba/dubbo -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.6.2</version>
        </dependency>
        <!-- 注册中心使用的是zookeeper，引入操作zookeeper的客户端端 -->
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-framework</artifactId>
            <version>2.12.0</version>
        </dependency>

    </dependencies>
</project>

OrderServiceImpl

package com.ty.service.impl;

import com.ty.bean.UserAddress;
import com.ty.service.OrderService;
import com.ty.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * 1、将服务提供者注册到注册中心（暴露服务）
 *         1）、导入dubbo依赖（2.6.2）\操作zookeeper的客户端(curator)
 *         2）、配置服务提供者
 *
 * 2、让服务消费者去注册中心订阅服务提供者的服务地址
 * @author lfy
 *
 */
@Service
public class OrderServiceImpl implements OrderService {

    @Autowired
    UserService userService;

    @Override
    public List<UserAddress> initOrder(String userId) {
        // TODO Auto-generated method stub
        System.out.println("用户id："+userId);
        //1、查询用户的收货地址
        List<UserAddress> addressList = userService.getUserAddressList(userId);
        for (UserAddress userAddress : addressList) {
            System.out.println(userAddress.getUserAddress());
        }
        return addressList;
    }

}

MainApplication

package com.ty;

import com.ty.service.OrderService;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;

public class MainApplication {

    @SuppressWarnings("resource")
    public static void main(String[] args) throws IOException {
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("consumer.xml");

        OrderService orderService = applicationContext.getBean(OrderService.class);

        orderService.initOrder("1");
        System.out.println("调用完成....");
        System.in.read();
    }

}

consumer.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://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://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
        http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd
        http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
    <context:component-scan base-package="com.ty.service.impl"></context:component-scan>

    <dubbo:application name="order-service-consumer"></dubbo:application>

    <dubbo:registry address="zookeeper://127.0.0.1:2181"></dubbo:registry>

    <!--  配置本地存根-->

    <!--声明需要调用的远程服务的接口；生成远程服务代理  -->
    <!--
        1）、精确优先 (方法级优先，接口级次之，全局配置再次之)
        2）、消费者设置优先(如果级别一样，则消费方优先，提供方次之)
    -->
    <!-- timeout="0" 默认是1000ms-->
    <!-- retries="":重试次数，不包含第一次调用，0代表不重试-->
    <!-- 幂等（设置重试次数）【查询、删除、修改】、非幂等（不能设置重试次数）【新增】 -->
    <dubbo:reference interface="com.ty.service.UserService"
        id="userService" timeout="5000" retries="3" version="*">
        <!-- <dubbo:method name="getUserAddressList" timeout="1000"></dubbo:method> -->
    </dubbo:reference>

    <!-- 配置当前消费者的统一规则：所有的服务都不检查 -->
    <dubbo:consumer check="false" timeout="5000"></dubbo:consumer>

    <dubbo:monitor protocol="registry"></dubbo:monitor>
    <!-- <dubbo:monitor address="127.0.0.1:7070"></dubbo:monitor> -->

</beans>

三、测试

1、启动zooker的服务以及上篇博文中的dubbo-admin(java -jar的方式启动)

2、启动user-service-providor的MainApplication中的main方法

E:\jdk\bin\java.exe "-javaagent:E:\utils\Intellij idea\IntelliJ IDEA 2018.3.2\lib\idea_rt.jar=51328:E:\utils\Intellij idea\IntelliJ IDEA 2018.3.2\bin" -Dfile.encoding=UTF-8 -classpath E:\jdk\jre\lib\charsets.jar;E:\jdk\jre\lib\deploy.jar;E:\jdk\jre\lib\ext\access-bridge-64.jar;E:\jdk\jre\lib\ext\cldrdata.jar;E:\jdk\jre\lib\ext\dnsns.jar;E:\jdk\jre\lib\ext\jaccess.jar;E:\jdk\jre\lib\ext\jfxrt.jar;E:\jdk\jre\lib\ext\localedata.jar;E:\jdk\jre\lib\ext\nashorn.jar;E:\jdk\jre\lib\ext\sunec.jar;E:\jdk\jre\lib\ext\sunjce_provider.jar;E:\jdk\jre\lib\ext\sunmscapi.jar;E:\jdk\jre\lib\ext\sunpkcs11.jar;E:\jdk\jre\lib\ext\zipfs.jar;E:\jdk\jre\lib\javaws.jar;E:\jdk\jre\lib\jce.jar;E:\jdk\jre\lib\jfr.jar;E:\jdk\jre\lib\jfxswt.jar;E:\jdk\jre\lib\jsse.jar;E:\jdk\jre\lib\management-agent.jar;E:\jdk\jre\lib\plugin.jar;E:\jdk\jre\lib\resources.jar;E:\jdk\jre\lib\rt.jar;E:\workspaceidea\dubbo\user-service-providor\target\classes;E:\workspaceidea\dubbo\gmall-interface\target\classes;E:\respository\com\alibaba\dubbo\2.6.2\dubbo-2.6.2.jar;E:\respository\org\springframework\spring-context\4.3.16.RELEASE\spring-context-4.3.16.RELEASE.jar;E:\respository\org\springframework\spring-aop\4.3.16.RELEASE\spring-aop-4.3.16.RELEASE.jar;E:\respository\org\springframework\spring-beans\4.3.16.RELEASE\spring-beans-4.3.16.RELEASE.jar;E:\respository\org\springframework\spring-core\4.3.16.RELEASE\spring-core-4.3.16.RELEASE.jar;E:\respository\commons-logging\commons-logging\1.2\commons-logging-1.2.jar;E:\respository\org\springframework\spring-expression\4.3.16.RELEASE\spring-expression-4.3.16.RELEASE.jar;E:\respository\org\javassist\javassist\3.20.0-GA\javassist-3.20.0-GA.jar;E:\respository\org\jboss\netty\netty\3.2.5.Final\netty-3.2.5.Final.jar;E:\respository\org\apache\curator\curator-framework\2.12.0\curator-framework-2.12.0.jar;E:\respository\org\apache\curator\curator-client\2.12.0\curator-client-2.12.0.jar;E:\respository\org\apache\zookeeper\zookeeper\3.4.8\zookeeper-3.4.8.jar;E:\respository\log4j\log4j\1.2.16\log4j-1.2.16.jar;E:\respository\jline\jline\0.9.94\jline-0.9.94.jar;E:\respository\io\netty\netty\3.7.0.Final\netty-3.7.0.Final.jar;E:\respository\com\google\guava\guava\16.0.1\guava-16.0.1.jar;E:\respository\org\slf4j\slf4j-api\1.7.6\slf4j-api-1.7.6.jar com.ty.MainApplication
log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

3、打开http://localhost:7001/

可以看到已经有两个服务了，说明user-service-providor启动ok

4、测试order-service-consumer(运行其main方法)

用户id：1
北京市昌平区宏福科技园综合楼3层
深圳市宝安区西部硅谷大厦B座3层（深圳分校）
调用完成....

说明消费方也调用成功

dubbo hello world已上传github：https://github.com/ali-mayun/dubbo