Dubbo、Spring、Zookeeper、集成基础案例(异步调用 Dubbo 2.6.x版本之前的异步调用方式)

摘要：最近抽时间系统的学习了Dubbo的一些内容，趁有时间，整理下，顺便记录下，以防以后回顾。前面我们学校了Dubbo的xml、注解方式，本次我们学习下Dubbo的异步调用 Dubbo 2.6.x版本之前的异步调用方式。

一：运行环境

1>:JDK 1.8

2>:IDEA 2018.1

3>:Zookeeper 3.x

4>:Maven 3.2

5>:Dubbo 2.8.4

二：项目结构

三：服务提供者

 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>micai-dubbo-chapter3</artifactId>
        <groupId>com.micai.dubbo</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>micai-dubbo-provider</artifactId>

    <name>micai-dubbo-provider</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>

    <properties>
        <spring.version>4.2.1.RELEASE</spring.version>
        <jdk.version>1.8</jdk.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.8.4</version>
            <exclusions>
                <exclusion>
                    <artifactId>spring</artifactId>
                    <groupId>org.springframework</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>com.101tec</groupId>
            <artifactId>zkclient</artifactId>
            <version>0.3</version>
        </dependency>
    </dependencies>

    <build>
        <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.7.0</version>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
</project>

UserService.java

package com.micai.dubbo.provider;

/**
 * @Auther: zhaoxinguo
 * @Date: 2018/9/11 16:18
 * @Description:
 */
public interface UserService {

    String getNameById(String id);
}

UserServiceImpl.java

package com.micai.dubbo.provider;

import com.alibaba.dubbo.config.annotation.Service;

/**
 * @Auther: zhaoxinguo
 * @Date: 2018/9/11 16:19
 * @Description:
 */
@Service(version = "1.0.0", timeout = 10000)
public class UserServiceImpl implements UserService {

    @Override
    public String getNameById(String id) {
        try {
            Thread.sleep(5000);//模拟业务执行
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return "admin" + id;
    }
}

Provider.java

package com.micai.dubbo;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;

/**
 * @Auther: zhaoxinguo
 * @Date: 2018/9/10 14:13
 * @Description:
 */
public class Provider {

    public static void main(String [] args) {
        ClassPathXmlApplicationContext classPathXmlApplicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        classPathXmlApplicationContext.start();
        try {
            System.in.read();//按任意键退出
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

applicationContext.xml

<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-4.2.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="hello-world-app"/>

    <!--使⽤zookeeper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"/>

    <!--<!–声明需要暴露的服务接口–>
    <dubbo:service interface="com.micai.dubbo.provider.DemoService" ref="demoService"/>
    <!–和本地bean一样实现服务–>
    <bean id="demoService" class="com.micai.dubbo.provider.DemoServiceImpl"/>-->

    <!--扫描注解包路径，多个包⽤逗号分隔，不填pacakge表示扫描当前ApplicationContext中所有的类-->
    <dubbo:annotation package="com.micai.dubbo.provider"/>

</beans>

四：服务消费者

  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>micai-dubbo-chapter3</artifactId>
        <groupId>com.micai.dubbo</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>micai-dubbo-consumer</artifactId>

    <name>micai-dubbo-consumer</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <spring.version>4.2.1.RELEASE</spring.version>
        <jdk.version>1.8</jdk.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.8.4</version>
            <exclusions>
                <exclusion>
                    <artifactId>spring</artifactId>
                    <groupId>org.springframework</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <!--zookeeper-->
        <dependency>
            <groupId>com.101tec</groupId>
            <artifactId>zkclient</artifactId>
            <version>0.3</version>
        </dependency>
        <dependency>
            <groupId>com.micai.dubbo</groupId>
            <artifactId>micai-dubbo-provider</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>

    <build>
        <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.7.0</version>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>
</project>

UserAction.java

package com.micai.dubbo.consumer;

import com.alibaba.dubbo.config.annotation.Reference;
import com.alibaba.dubbo.remoting.exchange.ResponseCallback;
import com.alibaba.dubbo.remoting.exchange.ResponseFuture;
import com.alibaba.dubbo.rpc.RpcContext;
import com.alibaba.dubbo.rpc.protocol.dubbo.FutureAdapter;
import com.micai.dubbo.provider.UserService;
import org.springframework.stereotype.Component;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;

/**
 * @Auther: zhaoxinguo
 * @Date: 2018/9/11 16:23
 * @Description: 异步调用 2.6.x版本之前的异步方式
 */
@Component
public class UserAction {

    // 异步调用 不等待消息发出 即刻返回
    @Reference(version = "1.0.0", async = true, sent = false)
    private UserService userService;

    // 通过RpcContext获取Future
    public void getUserName() {
        // 此调用会立即返回null
        userService.getNameById("123123");
        System.out.println("异步业务调用结束 " + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));
        // 拿到调用的Future引用，当结果返回后，会被通知和设置到此Future
        Future<Object> future = RpcContext.getContext().getFuture();
        try {
            String result = (String) future.get();
            System.out.println("异步回调返回结果 " + result + " " + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));
            // TODO 业务操作，比如记录日志等
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }
    }

    // 拿到Dubbo内置的ResponseFuture并设置回调
    public void getUserName2() {
        // 此调用会立即返回null
        userService.getNameById("123123");
        System.out.println("异步业务调用结束 " + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));
        // 拿到Dubbo内置的ResponseFuture并设置回调
        ResponseFuture responseFuture = ((FutureAdapter) RpcContext.getContext().getFuture()).getFuture();
        responseFuture.setCallback(new ResponseCallback() {
            @Override
            public void done(Object result) {
                System.out.println("异步回调返回结果 " + result + " " + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));
            }
            @Override
            public void caught(Throwable throwable) {
                throwable.printStackTrace();
            }
        });
    }
}

Consumer.java

package com.micai.dubbo;

import com.micai.dubbo.consumer.CallBackAction;
import com.micai.dubbo.consumer.DemoAction;
import com.micai.dubbo.consumer.UserAction;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @Auther: zhaoxinguo
 * @Date: 2018/9/11 14:36
 * @Description:
 */
public class Consumer {

    public static void main(String [] args) {
        ClassPathXmlApplicationContext classPathXmlApplicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        classPathXmlApplicationContext.start();

        // 2.6.x版本之前的异步调用方式
        UserAction userAction = (UserAction) classPathXmlApplicationContext.getBean("userAction");
        // 通过RpcContext获取Future
        userAction.getUserName();
        // 拿到Dubbo内置的ResponseFuture并设置回调
        userAction.getUserName2();

    }
}

applicationContext.xml

<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-4.2.xsd
       http://code.alibabatech.com/schema/dubbo
       http://code.alibabatech.com/schema/dubbo/dubbo.xsd">

    <!--消费方应用名、用于计算依赖关系，不是匹配条件，不要与提供方一样-->
    <dubbo:application name="consumer-of-helloworld-app"/>

    <!--使用zookeeper注册中心暴露发现服务地址-->
    <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demoService–>
    <dubbo:reference id="demoService" interface="com.micai.dubbo.provider.DemoService"/>-->

    <!--扫描注解包路径，多个包⽤逗号分隔，不填pacakge表示扫描当前ApplicationContext中所有的类-->
    <dubbo:annotation package="com.micai.dubbo.consumer"/>

</beans>

五：运行结果