Dubbo快速入门（附案例）

以下是一个简单的Dubbo入门示例，演示了如何使用Dubbo进行服务提供和服务消费。

1. 定义服务接口：

public interface GreetingsService {
    String sayHello(String name);
}

2. 实现服务：

public class GreetingsServiceImpl implements GreetingsService {
    @Override
    public String sayHello(String name) {
        return "Hello, " + name + "!";
    }
}

3. 配置服务提供者（provider.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.xsd
       http://code.alibabatech.com/schema/dubbo
       http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
 
    <dubbo:application name="demo-provider"/>
    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
    <dubbo:protocol name="dubbo" port="20880"/>
    <dubbo:service interface="GreetingsService" ref="greetingsService" />
 
    <bean id="greetingsService" class="GreetingsServiceImpl"/>
 
</beans>

4. 配置服务消费者（consumer.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.xsd
       http://code.alibabatech.com/schema/dubbo
       http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
 
    <dubbo:application name="demo-consumer"/>
    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
    <dubbo:reference id="greetingsService" interface="GreetingsService" />
 
</beans>

5. 服务提供者启动代码：

public class Provider {
    public static void main(String[] args) throws IOException {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"provider.xml"});
        context.start();
        System.in.read(); // 防止提供者立即退出
    }
}

6. 服务消费者调用代码：

public class Consumer {
    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"consumer.xml"});
        context.start();
        Gre