一、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">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>dubbo-tripple</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <dubbo.version>3.1.8</dubbo.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
            <version>${dubbo.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-dependencies-zookeeper-curator5</artifactId>
            <type>pom</type>
            <version>${dubbo.version}</version>
        </dependency>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>3.19.4</version>
        </dependency>
    </dependencies>

    <build>
        <extensions>
            <extension>
                <groupId>kr.motd.maven</groupId>
                <artifactId>os-maven-plugin</artifactId>
                <version>1.6.1</version>
            </extension>
        </extensions>
        <plugins>
            <plugin>
                <groupId>org.xolstice.maven.plugins</groupId>
                <artifactId>protobuf-maven-plugin</artifactId>
                <version>0.6.1</version>
                <configuration>
                    <protocArtifact>com.google.protobuf:protoc:3.19.4:exe:${os.detected.classifier}</protocArtifact>
                    <protocPlugins>
                        <protocPlugin>
                            <id>dubbo</id>
                            <groupId>org.apache.dubbo</groupId>
                            <artifactId>dubbo-compiler</artifactId>
                            <version>${dubbo.version}</version>
                            <mainClass>org.apache.dubbo.gen.tri.Dubbo3TripleGenerator</mainClass>
                        </protocPlugin>
                    </protocPlugins>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

二、编写通信接口

package cn.edu.tju;

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

三、编写接口的服务端实现：

package cn.edu.tju;

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

四、编写服务端主类：

package cn.edu.tju;

import org.apache.dubbo.common.constants.CommonConstants;
import org.apache.dubbo.config.ApplicationConfig;
import org.apache.dubbo.config.ProtocolConfig;
import org.apache.dubbo.config.RegistryConfig;
import org.apache.dubbo.config.ServiceConfig;
import org.apache.dubbo.config.bootstrap.DubboBootstrap;

import java.io.IOException;

public class MyDubboServer {

    public static void main(String[] args) throws IOException {
        ServiceConfig<Greeter> service = new ServiceConfig<>();
        service.setInterface(Greeter.class);
        service.setRef(new GreeterImpl());

        DubboBootstrap bootstrap = DubboBootstrap.getInstance();
        bootstrap.application(new ApplicationConfig("tri-pojo-server"))
                .registry(new RegistryConfig("zookeeper://xx.xx.xx.xx:2181"))
                .protocol(new ProtocolConfig(CommonConstants.TRIPLE, 50051))
                .service(service)
                .start();
        System.out.println("Dubbo triple pojo server started");
        System.in.read();
    }
}

其中注册中心为zookeeper 3.6.2
五、编写客户端主类：

package cn.edu.tju;

import org.apache.dubbo.common.constants.CommonConstants;
import org.apache.dubbo.config.ApplicationConfig;
import org.apache.dubbo.config.ReferenceConfig;
import org.apache.dubbo.config.RegistryConfig;
import org.apache.dubbo.config.bootstrap.DubboBootstrap;

public class MyDubboClient {
    public static void main(String[] args) {
        DubboBootstrap bootstrap = DubboBootstrap.getInstance();
        ReferenceConfig<Greeter> ref = new ReferenceConfig<>();
        ref.setInterface(Greeter.class);
        ref.setProtocol(CommonConstants.TRIPLE);
        ref.setTimeout(3000);
        bootstrap.application(new ApplicationConfig("tri-pojo-client"))
                .registry(new RegistryConfig("zookeeper://xx.xx.xx.xx:2181"))
                .reference(ref)
                .start();

        Greeter greeter = ref.get();
        String reply = greeter.sayHello("pojo");
        System.out.println("Received reply:" + reply);
    }
}

分别运行客户端和服务器：


也可以在src/main/proto目录下创建.proto文件，

syntax = "proto3";

option java_multiple_files = true;
option java_package = "com.example";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

message HelloRequest {
  string name = 1;
}

message HelloReply {
  string message = 1;
}
service Greeter{
  rpc greet(HelloRequest) returns (HelloReply);
}

然后使用compile生成接口定义文件

然后将生成的java代码拷贝到src下，再编写接口实现文件以及服务端主类和客户端主类，这种方式实际是使用了grpc进行了通信。