Java-Sdk: 协议概述

Mon, 01 Jan 0001 00:00:00 +0000

Java-Sdk: 使用说明

Mon, 01 Jan 0001 00:00:00 +0000

Triple 协议是 Dubbo3 的主力协议，完整兼容 gRPC over HTTP/2，并在协议层面扩展了负载均衡和流量控制相关机制。本文档旨在指导用户正确的使用 Triple 协议。

在开始前，需要决定服务使用的序列化方式，如果为新服务，推荐使用 protobuf 作为默认序列化，在性能和跨语言上的效果都会更好。如果是原有服务想进行协议升级，Triple 协议也已经支持其他序列化方式，如 Hessian / JSON 等

Protobuf

编写 IDL 文件

syntax = "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;

// The request message containing the user's name.
message HelloRequest {
 string name = 1;
}

// The response message containing the greetings
message HelloReply {
 string message = 1;
}

添加编译 protobuf 的 extension 和 plugin (以 maven 为例)

 <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:3.7.1:exe:${os.detected.classifier}</protocArtifact>
 <pluginId>triple-java</pluginId>
 <outputDirectory>build/generated/source/proto/main/java</outputDirectory>
 </configuration>
 <executions>
 <execution>
 <goals>
 <goal>compile</goal>
 <goal>test-compile</goal>
 </goals>
 </execution>
 </executions>
 </plugin>
 </plugins>

构建/ 编译生成 protobuf Message 类
```
$ mvn clean install
```

Unary 方式

编写 Java 接口

import org.apache.dubbo.hello.HelloReply;
import org.apache.dubbo.hello.HelloRequest;

public interface IGreeter {
 /**
 * <pre>
 * Sends a greeting
 * </pre>
 */
 HelloReply sayHello(HelloRequest request);

}

创建 Provider

 public static void main(String[] args) throws InterruptedException {
 ServiceConfig<IGreeter> service = new ServiceConfig<>();
 service.setInterface(IGreeter.class);
 service.setRef(new IGreeter1Impl());
 // 这里需要显示声明使用的协议为triple
 service.setProtocol(new ProtocolConfig(CommonConstants.TRIPLE, 50051));
 service.setApplication(new ApplicationConfig("demo-provider"));
 service.setRegistry(new RegistryConfig("zookeeper://127.0.0.1:2181"));
 service.export();
 System.out.println("dubbo service started");
 new CountDownLatch(1).await();
 }

创建 Consumer

public static void main(String[] args) throws IOException {
 ReferenceConfig<IGreeter> ref = new ReferenceConfig<>();
 ref.setInterface(IGreeter.class);
 ref.setCheck(false);
 ref.setInterface(IGreeter.class);
 ref.setCheck(false);
 ref.setProtocol(CommonConstants.TRIPLE);
 ref.setLazy(true);
 ref.setTimeout(100000);
 ref.setApplication(new ApplicationConfig("demo-consumer"));
 ref.setRegistry(new RegistryConfig("zookeeper://127.0.0.1:2181"));
 final IGreeter iGreeter = ref.get();

 System.out.println("dubbo ref started");
 try {
 final HelloReply reply = iGreeter.sayHello(HelloRequest.newBuilder()
 .setName("name")
 .build());
 TimeUnit.SECONDS.sleep(1);
 System.out.println("Reply:" + reply);
 } catch (Throwable t) {
 t.printStackTrace();
 }
 System.in.read();
}

运行 Provider 和 Consumer ,可以看到请求正常返回了

Reply:message: “name”

stream 方式

编写 Java 接口

import org.apache.dubbo.hello.HelloReply;
import org.apache.dubbo.hello.HelloRequest;

public interface IGreeter {
 /**
 * <pre>
 * Sends greeting by stream
 * </pre>
 */
 StreamObserver<HelloRequest> sayHello(StreamObserver<HelloReply> replyObserver);

}

编写实现类

public class IStreamGreeterImpl implements IStreamGreeter {

 @Override
 public StreamObserver<HelloRequest> sayHello(StreamObserver<HelloReply> replyObserver) {

 return new StreamObserver<HelloRequest>() {
 private List<HelloReply> replyList = new ArrayList<>();

 @Override
 public void onNext(HelloRequest helloRequest) {
 System.out.println("onNext receive request name:" + helloRequest.getName());
 replyList.add(HelloReply.newBuilder()
 .setMessage("receive name:" + helloRequest.getName())
 .build());
 }

 @Override
 public void onError(Throwable cause) {
 System.out.println("onError");
 replyObserver.onError(cause);
 }

 @Override
 public void onCompleted() {
 System.out.println("onComplete receive request size:" + replyList.size());
 for (HelloReply reply : replyList) {
 replyObserver.onNext(reply);
 }
 replyObserver.onCompleted();
 }
 };
 }
}

创建 Provider

public class StreamProvider {
 public static void main(String[] args) throws InterruptedException {
 ServiceConfig<IStreamGreeter> service = new ServiceConfig<>();
 service.setInterface(IStreamGreeter.class);
 service.setRef(new IStreamGreeterImpl());
 service.setProtocol(new ProtocolConfig(CommonConstants.TRIPLE, 50051));
 service.setApplication(new ApplicationConfig("stream-provider"));
 service.setRegistry(new RegistryConfig("zookeeper://127.0.0.1:2181"));
 service.export();
 System.out.println("dubbo service started");
 new CountDownLatch(1).await();
 }
}

创建 Consumer

public class StreamConsumer {
 public static void main(String[] args) throws InterruptedException, IOException {
 ReferenceConfig<IStreamGreeter> ref = new ReferenceConfig<>();
 ref.setInterface(IStreamGreeter.class);
 ref.setCheck(false);
 ref.setProtocol(CommonConstants.TRIPLE);
 ref.setLazy(true);
 ref.setTimeout(100000);
 ref.setApplication(new ApplicationConfig("stream-consumer"));
 ref.setRegistry(new RegistryConfig("zookeeper://mse-6e9fda00-p.zk.mse.aliyuncs.com:2181"));
 final IStreamGreeter iStreamGreeter = ref.get();

 System.out.println("dubbo ref started");
 try {

 StreamObserver<HelloRequest> streamObserver = iStreamGreeter.sayHello(new StreamObserver<HelloReply>() {
 @Override
 public void onNext(HelloReply reply) {
 System.out.println("onNext");
 System.out.println(reply.getMessage());
 }

 @Override
 public void onError(Throwable throwable) {
 System.out.println("onError:" + throwable.getMessage());
 }

 @Override
 public void onCompleted() {
 System.out.println("onCompleted");
 }
 });

 streamObserver.onNext(HelloRequest.newBuilder()
 .setName("tony")
 .build());

 streamObserver.onNext(HelloRequest.newBuilder()
 .setName("nick")
 .build());

 streamObserver.onCompleted();
 } catch (Throwable t) {
 t.printStackTrace();
 }
 System.in.read();
 }
}

运行 Provider 和 Consumer ,可以看到请求正常返回了

onNext
receive name:tony
onNext
receive name:nick
onCompleted

其他序列化方式

省略上文中的 1-3 步，指定 Provider 和 Consumer 使用的协议即可完成协议升级。

示例程序

本文的示例程序可以在 triple-samples 找到