XML 配置
- XML完整示例
  - 服务提供者
  - 服务消费者
    - 通过 Spring 配置引用远程服务
    - 加载 Spring 配置，并调用远程服务
- 更多示例

XML 配置

以 Spring XML 开发 Dubbo 应用

Dubbo 有基于 Spring Schema 扩展的自定义配置组件，XML 支持的配置项与配置参考手册中描述的一一对。本文使用的示例请参考 dubbo-samples-spring-xml

XML完整示例

服务提供者

定义服务接口

DemoService.java：

package org.apache.dubbo.demo;
public interface DemoService {
    String sayHello(String name);
}

在服务提供方实现接口

DemoServiceImpl.java：

package org.apache.dubbo.demo.provider;
import org.apache.dubbo.demo.DemoService;
public class DemoServiceImpl implements DemoService {
    public String sayHello(String name) {
        return "Hello " + name;
    }
}

用 Spring 配置声明暴露服务

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
       xmlns="http://www.springframework.org/schema/beans" 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 http://www.springframework.org/schema/context/spring-context.xsd">
    <context:property-placeholder/>
    <dubbo:application name="demo-provider"/>
    <dubbo:registry address="zookeeper://${zookeeper.address:127.0.0.1}:2181"/>
    <dubbo:provider token="true"/>
    <bean id="demoService" class="org.apache.dubbo.samples.basic.impl.DemoServiceImpl"/>
    <dubbo:service interface="org.apache.dubbo.samples.basic.api.DemoService" ref="demoService"/>
</beans>

加载 Spring 配置

public class Application {
    public static void main(String[] args) throws InterruptedException {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("spring/dubbo-demo-provider.xml");
        context.start();
        System.out.println("dubbo service started");
        // to hang up main thread
        new CountDownLatch(1).await();
    }
}

服务消费者

通过 Spring 配置引用远程服务

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
       xmlns="http://www.springframework.org/schema/beans" 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 http://www.springframework.org/schema/context/spring-context.xsd">
    <context:property-placeholder/>
    <dubbo:application name="demo-consumer"/>
    <dubbo:registry address="zookeeper://${zookeeper.address:127.0.0.1}:2181"/>
    <dubbo:reference id="demoService" check="true" interface="org.apache.dubbo.samples.basic.api.DemoService"/>
</beans>

加载 Spring 配置，并调用远程服务

public class Application {
    public static void main(String[] args) throws IOException {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("spring/dubbo-demo-consumer.xml");
        context.start();
        GreetingsService greetingsService = (GreetingsService) context.getBean("greetingsService");
        String message = greetingsService.sayHi("dubbo");
        System.out.println("Receive result ======> " + message);
        System.in.read();
        System.exit(0);
    }
}

更多示例

版本与分组

<dubbo:service interface="com.foo.BarService" version="1.0.0" />
<dubbo:service interface="org.apache.dubbo.example.service.DemoService" group="demo2"/>

集群容错

配置 failover 重试次数：

<dubbo:service retries="2" />
<dubbo:reference>
    <dubbo:method name="findFoo" retries="2" />
</dubbo:reference>

多协议

<dubbo:application name="world"  />
<dubbo:registry id="registry" address="10.20.141.150:9090" username="admin" password="hello1234" />
<!-- 多协议配置 -->
<dubbo:protocol name="dubbo" port="20880" />
<dubbo:protocol name="rmi" port="1099" />
<!-- 使用dubbo协议暴露服务 -->
<dubbo:service interface="com.alibaba.hello.api.HelloService" version="1.0.0" ref="helloService" protocol="dubbo" />
<!-- 使用rmi协议暴露服务 -->
<dubbo:service interface="com.alibaba.hello.api.DemoService" version="1.0.0" ref="demoService" protocol="rmi" />

多注册中心

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">
    <dubbo:application name="world"  />
    <!-- 多注册中心配置 -->
    <dubbo:registry id="chinaRegistry" address="10.20.141.150:9090" />
    <dubbo:registry id="intlRegistry" address="10.20.154.177:9010" default="false" />
    <!-- 向中文站注册中心注册 -->
    <dubbo:service interface="com.alibaba.hello.api.HelloService" version="1.0.0" ref="helloService" registry="chinaRegistry" />
    <!-- 向国际站注册中心注册 -->
    <dubbo:service interface="com.alibaba.hello.api.DemoService" version="1.0.0" ref="demoService" registry="intlRegistry" />
</beans>

全局默认值

指定全局默认超时时间，多所有服务生效：

<dubbo:provider timeout="5000" />
<dubbo:consumer timeout="5000" />

基于分组的默认值：

<dubbo:provider timeout="5000">
    <dubbo:service interface="com.alibaba.hello.api.HelloService" ref="helloService"/>
    <dubbo:service interface="com.alibaba.hello.api.HelloService2" ref="helloService2"/>
</dubbo:provider>
<dubbo:provider timeout="8000">
    <dubbo:service interface="com.alibaba.hello.api.DemoService" ref="demoService"/>
    <dubbo:service interface="com.alibaba.hello.api.DemoService2" ref="demoService2"/>
</dubbo:provider>

最后修改 September 13, 2024: Refactor website structure (#2860) (1a4b998f54b)