Dubbo：泛化调用

#Dubbo#

泛化调用，是非常了灵活的一个服务方/调用方实现方式，不需要引入协议包，可以直接构建服务端或消费端。

Dubbo的泛化调用 有详细的使用介绍。

示例

协议

package demo.contract;

import demo.contract.request.HiRequest;
import demo.contract.response.HiResponse;

public interface DemoService {

    String sayHello(String name);

    HiResponse sayHi(HiRequest request);

}

package demo.contract.request;

import lombok.Data;
import lombok.EqualsAndHashCode;

import java.io.Serializable;

@Data
@EqualsAndHashCode(callSuper = false)
public class HiRequest implements Serializable {

    private String msg;

}

package demo.contract.response;

import lombok.Data;
import lombok.EqualsAndHashCode;

import java.io.Serializable;

@Data
@EqualsAndHashCode(callSuper = false)
public class HiResponse  implements Serializable {

    private String result;

}

服务端实现

package demo.provider;

import demo.contract.DemoService;
import demo.contract.request.HiRequest;
import demo.contract.response.HiResponse;
import org.springframework.stereotype.Service;

@Service
public class DemoServiceImpl implements DemoService {

    @Override
    public String sayHello(String name) {
        return "Hello, " + name;
    }

    @Override
    public HiResponse sayHi(HiRequest request) {
        HiResponse response = new HiResponse();
        response.setResult("Hi, " + request.getMsg());
        return response;
    }

}

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

    <dubbo:application name="hello-world-app"></dubbo:application>
    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
    <dubbo:protocol name="dubbo" port="20881"/>

    <dubbo:service interface="demo.contract.DemoService"
                   class="demo.provider.DemoServiceImpl"
    />

</beans>

基于泛化调用实现的消费端

示例1：

package demo.consumer;

import org.apache.dubbo.config.ApplicationConfig;
import org.apache.dubbo.config.ReferenceConfig;
import org.apache.dubbo.config.RegistryConfig;
import org.apache.dubbo.rpc.service.GenericService;

public class ConsumerMainV1 {

    public static void main(String[] args) {
        ApplicationConfig application = new ApplicationConfig();
        application.setName("api-generic-consumer");
        RegistryConfig registry = new RegistryConfig();
        registry.setAddress("zookeeper://127.0.0.1:2181");
        application.setRegistry(registry);

        ReferenceConfig<GenericService> reference = new ReferenceConfig<>();
        // 弱类型接口名
        reference.setInterface("demo.contract.DemoService");
        // 声明为泛化接口
        reference.setGeneric(true);
        reference.setApplication(application);

        // 用com.apache.dubbo.rpc.service.GenericService可以替代所有接口引用
        GenericService genericService = reference.get();

        Object name = genericService.$invoke("sayHello", new String[]{String.class.getName()}, new Object[]{ "世界" });
        System.out.println(name.getClass().getName());
        System.out.println(name);

    }

}

运行结果：

java.lang.String
Hello, 世界

示例2：

package demo.consumer;

import org.apache.dubbo.config.ApplicationConfig;
import org.apache.dubbo.config.ReferenceConfig;
import org.apache.dubbo.config.RegistryConfig;
import org.apache.dubbo.rpc.service.GenericService;

import java.util.HashMap;
import java.util.Map;

public class ConsumerMainV2 {

    public static void main(String[] args) {
        ApplicationConfig application = new ApplicationConfig();
        application.setName("api-generic-consumer");
        RegistryConfig registry = new RegistryConfig();
        registry.setAddress("zookeeper://127.0.0.1:2181");
        application.setRegistry(registry);

        ReferenceConfig<GenericService> reference = new ReferenceConfig<>();
        // 弱类型接口名
        reference.setInterface("demo.contract.DemoService");
        // 声明为泛化接口
        reference.setGeneric(true);
        reference.setApplication(application);

        // 用com.apache.dubbo.rpc.service.GenericService可以替代所有接口引用
        GenericService genericService = reference.get();

        Map<String, Object> param = new HashMap<>();
        param.put("msg", "World!");

        Object name = genericService.$invoke(
                "sayHi",
                new String[]{"demo.contract.request.HiRequest"},
                new Object[]{ param }
                );
        System.out.println(name.getClass().getName());
        System.out.println(name);

    }

}

运行结果：

java.util.HashMap
{result=Hi, World!, class=demo.contract.response.HiResponse}

示例3：

package demo.consumer;

import org.apache.dubbo.config.ApplicationConfig;
import org.apache.dubbo.config.ReferenceConfig;
import org.apache.dubbo.config.RegistryConfig;
import org.apache.dubbo.rpc.service.GenericService;

import java.util.HashMap;
import java.util.Map;

public class ConsumerMainV3 {

    public static void main(String[] args) {
        ApplicationConfig application = new ApplicationConfig();
        application.setName("api-generic-consumer");

        ReferenceConfig<GenericService> reference = new ReferenceConfig<>();
        // 弱类型接口名
        reference.setInterface("demo.contract.DemoService");
        // 服务直连，不经过 zookeeper
        reference.setUrl("dubbo://127.0.0.1:20881");
        // 声明为泛化接口
        reference.setGeneric(true);
        reference.setApplication(application);

        // 用com.apache.dubbo.rpc.service.GenericService可以替代所有接口引用
        GenericService genericService = reference.get();

        Map<String, Object> param = new HashMap<>();
        param.put("msg", "World!");

        Object name = genericService.$invoke(
                "sayHi",
                new String[]{"demo.contract.request.HiRequest"},
                new Object[]{ param }
                );
        System.out.println(name.getClass().getName());
        System.out.println(name);

    }

}

运行结果：

java.util.HashMap
{result=Hi, World!, class=demo.contract.response.HiResponse}

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