[Original] RPC call is implemented through Dubbo annotation, while dubbo annotation rpc call

[Original] RPC call is implemented through Dubbo annotation, while dubbo annotation rpc call
There are two ways to start the Dubbo service: 1 is configured through xml, 2 is implemented through annotation, which is similar to Spring.

 

 

• The XML configuration is as follows:

  <? 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"> <! -- Provider application information for dependency calculation --> <dubbo: application name = "find_all_goods"/> <! -- Use the multicast broadcast registration center to expose the service address --> <! -- <Dubbo: registry address = "multicast: // 224.5.6.7: 1234"/> --> <! -- Use the zookeeper registration center to expose the service address --> <dubbo: registry address = "zookeeper: // 127.0.0.1: 2181"/> <! -- Expose services on port 20880 using dubbo protocol --> <dubbo: protocol name = "dubbo" port = "20880"/> <! -- Declare the service interface to be exposed (note the interface, not the implementation class) --> <dubbo: service interface = "com. zdd. dubbo. provider. goodsService "ref =" goodsService "/> <! -- Here is the specific implementation class. The id must be consistent with the Service Interface ref exposed above, dubbo registers the corresponding service through this --> <bean id = "goodsService" class = "com. zdd. dubbo. provider. goodsServiceImpl "> </bean> </beans>

  The code above exposes the interface through the dubbo: service interface tag and automatically registers it to zookeeper when the program starts.

 

• The consumer call method is configured as follows:

  <? 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"> <! -- Consumer application name, used to calculate dependencies. It is not a matching condition. Do not use the same name as the provider --> <dubbo: application name = "dubbo-consumer"/> <! -- Use the multicast broadcast registration center to expose the Discovery Service address --> <! -- <Dubbo: registry address = "multicast: // 224.5.6.7: 1234"/> --> <dubbo: registry address = "zookeeper: // 127.0.0.1: 2181"/> <! -- Generate a remote service proxy, which can be called like a local bean --> <dubbo: reference id = "goodsService" interface = "com. zdd. dubbo. provider. goodsService "/> </beans>

  Then we can call the local service like spring. The Code is as follows:

ApplicationContext  dubbo_cusumer = new ClassPathXmlApplicationContext("file:D:/workspace/GZDTL_TRUNK/zdd-web-consumer/spring/dubbo-consumer.xml");       dubbo_cusumer.getBean("goodsService");

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The preceding section uses xml to configure dubbo. The following section uses annotations to configure dubbo. You can compare the differences.

 

 

 

• The dubbo. xml configured by annotation is as follows:

  <? 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" xmlns: context = "http://www.springframework.org/schema/context" xsi: schemaLocation = "http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd http://www.springframework.org/schema/beans http://www.spri Ngframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd "> <! -- Provider application information for dependency calculation --> <dubbo: application name = "dubbo_provider"/> <! -- Use the multicast broadcast registry to expose the service address <dubbo: registry address = "multicast: // 224.5.6.7: 1234"/> --> <! -- Use the zookeeper registration center to expose the service address --> <dubbo: registry address = "zookeeper: // 127.0.0.1: 2181"/> <! -- Expose services on port 20880 using dubbo protocol --> <dubbo: protocol name = "dubbo" port = "20880"/> <! -- Specific implementation bean <bean id = "demoService" class = "com. unj. dubbotest. provider. impl. DemoServiceImpl"/> --> <! -- Declare the service interface to be exposed <dubbo: service interface = "com. unj. dubbotest. provider. DemoService" ref = "demoService"/> --> <! -- Expose the interface using annotations --> <dubbo: annotation package = "com. dubbo. provide"/> <! -- Add spring annotation scan --> <! -- <Context: component-scan base-package = "com. dubbo. provide"/> --> </beans>

  The preceding scan uses dubbo: annotation package to scan com. dubbo. all the packages in provide, similar to spring's context: component-scan base-package, scan dubbo-related annotations, in this way, we do not need to configure dubbo: service interface for each service interface in xml.

 

• The annotation-based service implementation class is as follows:

  package com.dubbo.provide;import com.alibaba.dubbo.config.annotation.Service;@Servicepublic class DubboPro implements DubboProInterface {    public void print() {        System.out.println("is ok");            }}

  Note that the Service annotation is the dubbo annotation instead of spring, which is located in the annotaion directory of dubbo. jar:

• The consumer annotation method call class is as follows:

package com.dubbo.consumer;import org.springframework.stereotype.Component;import com.alibaba.dubbo.config.annotation.Reference;import com.dubbo.provide.DubboProInterface;@Componentpublic class DubboConsumer{    @Reference     DubboProInterface dubboProInterface;        public void print(){        System.out.println(dubboProInterface);        dubboProInterface.print();    }}

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Through the @ Reference annotation, dubbo will automatically help our proxy interface during scanning, and then call the remote service through rpc

 

 

References: http://dubbo.io/User+Guide-zh.htm#UserGuide-zh-%E6%B3%A8%E8%A7%A3%E9%85%8D%E7%BD% AE