gprc-java与golang分别实现服务端,客户端,跨语言通信(一.java实现)

1.在pom中引入

<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-netty</artifactId>
    <version>1.18.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/io.grpc/grpc-protobuf -->
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-protobuf</artifactId>
    <version>1.18.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/io.grpc/grpc-stub -->
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-stub</artifactId>
    <version>1.18.0</version>
</dependency>

2.maven配置

<build>
    <extensions>
        <extension>
            <groupId>kr.motd.maven</groupId>
            <artifactId>os-maven-plugin</artifactId><!--引入操作系统os设置的属性插件,否则${os.detected.classifier} 操作系统版本会找不到 -->
            <version>1.5.0.Final</version>
        </extension>
    </extensions>
    <plugins>
        <!--添加编译proto文件的编译程序和对应的编译插件-->
        <plugin>
            <groupId>org.xolstice.maven.plugins</groupId>
            <artifactId>protobuf-maven-plugin</artifactId>
            <version>0.5.1</version>
            <configuration>
                <protocArtifact>com.google.protobuf:protoc:3.5.1-1:exe:${os.detected.classifier}</protocArtifact>
                <pluginId>grpc-java</pluginId>
                <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.14.0:exe:${os.detected.classifier}</pluginArtifact>
            </configuration>
            <executions>
                <execution>
                    <goals>
                        <goal>compile</goal>
                        <goal>compile-custom</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

3.编写IDL文件, 因为要夸语言调用, 所以和golang的使用同一个文件,除了option之外, 所有的东西不要改!!!

syntax = "proto3";

option java_multiple_files = true;
option java_package = "cn.com.xu.grpc";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

// The greeting service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

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

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

4.生成文件

5.客户端代码

public class GrpcClient {
   private final ManagedChannel channel;
   private final GreeterGrpc.GreeterBlockingStub blockingStub;

   public GrpcClient(String host,int port){
      channel = ManagedChannelBuilder.forAddress(host,port)
            .usePlaintext(true)
            .build();

      blockingStub = GreeterGrpc.newBlockingStub(channel);
   }

   public void shutdown() throws InterruptedException {
      channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);
   }

   public  void greet(String name){
      HelloRequest request = HelloRequest.newBuilder().setName(name).build();
      HelloReply response = blockingStub.sayHello(request);
      System.out.println("this is java client, response..." + response.getMessage());
   }

   public static void main(String[] args) throws InterruptedException {
      GrpcClient client = new GrpcClient("localhost",50001);
      client.greet("this is java client");
   }

}

6.服务端代码

public class GrpcServer {
   private int port = 50001;
   private Server server;

   private void start() throws IOException {
      server = ServerBuilder.forPort(port)
            .addService(new GreeterImpl())
            .build()
            .start();

      System.out.println("service start...");

      Runtime.getRuntime().addShutdownHook(new Thread() {

         @Override
         public void run() {

            System.err.println("*** shutting down gRPC server since JVM is shutting down");
            GrpcServer.this.stop();
            System.err.println("*** server shut down");
         }
      });
   }

   private void stop() {
      if (server != null) {
         server.shutdown();
      }
   }

   // block 一直到退出程序
   private void blockUntilShutdown() throws InterruptedException {
      if (server != null) {
         server.awaitTermination();
      }
   }

   public static void main(String[] args) throws IOException, InterruptedException {

      final GrpcServer server = new GrpcServer();
      server.start();
      server.blockUntilShutdown();
   }

   // 实现 定义一个实现服务接口的类
   private class GreeterImpl extends GreeterGrpc.GreeterImplBase {
      public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
         System.out.println("this is java service, request..."+req.getName());
         HelloReply reply = HelloReply.newBuilder().setMessage(("this is java service")).build();
         responseObserver.onNext(reply);
         responseObserver.onCompleted();
      }
   }

}