从零演示如何基于 IDL 方式来定义 Dubbo 服务并使用 Triple 协议
使用 IDL 定义服务具有更好的跨语言友好性，对于 Dubbo3 新用户而言，我们推荐使用这种方式。
然而 Triple 协议并不是和 IDL 强绑定的，也可以使用 Java Interface + Pojo 的方式定义服务并启用 Triple 协议，具体可参见示例。
更多 Triple 和 IDL 使用方式，请参考官方示例
前置条件
创建工程
首先创建一个空的 maven 工程
$ mvn archetype:generate \ -DgroupId=org.apache.dubbo \ -DartifactId=tri-stub-demo \ -DarchetypeArtifactId=maven-archetype-quickstart \ -DarchetypeVersion=1.4 \ -DarchetypeGroupId=org.apache.maven.archetypes \ -Dversion=1.0-SNAPSHOT切换到工程目录
$ cd tri-stub-demo在
pom.xml中设置 JDK 版本，添加 Dubbo 依赖和插件<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> </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>3.0.8</version> </dependency> <dependency> <groupId>org.apache.dubbo</groupId> <artifactId>dubbo-dependencies-zookeeper-curator5</artifactId> <type>pom</type> <version>3.0.8</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>0.0.4.1-SNAPSHOT</version> <mainClass>org.apache.dubbo.gen.tri.Dubbo3TripleGenerator</mainClass> </protocPlugin> </protocPlugins> </configuration> <executions> <execution> <goals> <goal>compile</goal> </goals> </execution> </executions> </plugin> </plugins> </build>添加接口定义文件
src/main/proto/hello.proto，Dubbo 使用 Protobuf 作为 IDLsyntax = "proto3"; option java_multiple_files = true; option java_package = "org.apache.dubbo.hello"; 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); }编译 IDL
$ mvn clean install编译成功后，可以看到
target/generated-sources/protobuf/java目录下生成了代码文件$ ls org/apache/dubbo/hello/ DubboGreeterTriple.java HelloReply.java HelloRequest.java HelloWorldProto.java Greeter.java HelloReplyOrBuilder.java HelloRequestOrBuilder.java添加服务端接口实现
src/main/java/org/apache/dubbo/GreeterImpl.javapackage org.apache.dubbo; import org.apache.dubbo.hello.DubboGreeterTriple; import org.apache.dubbo.hello.HelloReply; import org.apache.dubbo.hello.HelloRequest; public class GreeterImpl extends DubboGreeterTriple.GreeterImplBase { @Override public HelloReply greet(HelloRequest request) { return HelloReply.newBuilder() .setMessage("Hello," + request.getName() + "!") .build(); } }添加服务端启动类
src/main/java/org/apache/dubbo/MyDubboServer.javapackage org.apache.dubbo; 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 org.apache.dubbo.hello.Greeter; 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-stub-server")) .registry(new RegistryConfig("multicast://127.0.0.1:2181")) .protocol(new ProtocolConfig(CommonConstants.TRIPLE, 50051)) .service(service) .start(); System.out.println("Dubbo triple stub server started"); System.in.read(); } }添加客户端启动类
src/main/java/org/apache/dubbo/MyDubboClient.javapackage org.apache.dubbo; 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; import org.apache.dubbo.hello.Greeter; import org.apache.dubbo.hello.HelloReply; import org.apache.dubbo.hello.HelloRequest; 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.setProxy(CommonConstants.NATIVE_STUB); ref.setTimeout(3000); bootstrap.application(new ApplicationConfig("tri-stub-client")) .registry(new RegistryConfig("zookeeper://127.0.0.1:2181")) .reference(ref) .start(); Greeter greeter = ref.get(); HelloRequest request = HelloRequest.newBuilder().setName("Demo").build(); HelloReply reply = greeter.greet(request); System.out.println("Received reply:" + reply); } }编译代码
$ mvn clean install启动服务端
$ mvn org.codehaus.mojo:exec-maven-plugin:3.0.0:java -Dexec.mainClass="org.apache.dubbo.MyDubboServer" Dubbo triple stub server started打开新的终端，启动客户端
$ mvn org.codehaus.mojo:exec-maven-plugin:3.0.0:java -Dexec.mainClass="org.apache.dubbo.MyDubboClient" Received reply:message: "Hello,Demo!"
