JAVA grpc调用方式

代码已上传代码仓库GITHUB：https://github.com/LynHB/ProjectA/tree/master/src/main/java/study/grpc

工具准备

1.通过proto文件生成java类

命令：
[protobuf exe path] --java_out=[需要生成java的位置]

protoc.exe ./TestUser.proto --java_out=./

2.通过proto文件生成java grpc类

命令：
[protobuf exe path] --plugin=[protoc-gen-grpc-java exe path] --grpc-java_out=[需要生成java的位置] [proto文件位置]

D:\protobuf\bin\protoc --plugin=protoc-gen-grpc-java=D:\protobuf\bin\protoc-gen-grpc-java-1.30.2-windows-x86_64.exe --grpc-java_out=./ ./scheduler.proto

3 Java maven 依赖

        1.30.2
    


    
        
            io.grpc
            grpc-stub
            ${grpc.version}
        
        
            io.grpc
            grpc-netty-shaded
            ${grpc.version}
        
        
            io.grpc
            grpc-protobuf
            ${grpc.version}
        
    

4.Server端编写

4.1 编写protobuf文件

下面是定义一个简单的protobuf grpc文件，service块内定义调用的function，message定义的是结构体。

syntax = "proto3";

// 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;
}

4.2 创建grpc和protobuf java类

先根据1和2生成对应的实体和rpc服务类

cd D:\IDEAData\ProjectA1\src\main\java\study\grpc\proto\
D:\IDEAData\ProjectA1\src\main\java\study\grpc\proto>D:\protobuf\bin\protoc --plugin=protoc-gen-grpc-java=D:\protobuf\bin\protoc-gen-grpc-java-1.30.2-windows-x86_64.exe --grpc-java_out=./ Greeter.proto
D:\protobuf\bin\protoc --java_out=./ Greeter.proto

GreeterOuterClass和GreeterGrpc就是对应命令生成的java文件。

文件目录结构

4.3 编写GreeterServiceImpl

package study.grpc.service;

import io.grpc.stub.StreamObserver;
import study.grpc.pojo.GreeterOuterClass.*;
import study.grpc.rpc.GreeterGrpc;

/**
 * @Author LynHB
 * @Description : grpc实现接口
 * @Date 19:53 2020/7/29
 **/
public class GreeterServiceImpl extends GreeterGrpc.GreeterImplBase {
    @Override
    public void sayHello(HelloRequest req, StreamObserver responseObserver) {
        HelloReply reply = HelloReply.newBuilder().setMessage("Hello " + req.getName()).build();
        responseObserver.onNext(reply);
        responseObserver.onCompleted();
    }
}

4.4 编写Server入口类

package study.grpc;

import io.grpc.Server;
import io.grpc.ServerBuilder;
import lombok.extern.log4j.Log4j2;
import study.grpc.service.GreeterServiceImpl;

import java.io.IOException;
import java.util.concurrent.TimeUnit;

/**
 * @Author LynHB
 * @Description :g rpc server入口类
 * @Date 19:55 2020/7/29
 **/
@Log4j2
public class ServerMain {
    private final int port;
    private final Server server;

    public ServerMain(int port){
        this.port = port;
        /*
         * 创建Server
         * addService()添加对应的服务
         * forPort()指定端口
         */
        this.server = ServerBuilder.forPort(port).addService(new GreeterServiceImpl()).build();
    }


    public void start() throws IOException{
        server.start();
        log.info("Started server listening on " + port);
        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            try {
                ServerMain.this.stop();
            } catch (InterruptedException e) {
                e.printStackTrace(System.err);
            }
            log.error("Server shut down.");
        }));
    }

    public void stop() throws InterruptedException{
        if(server != null){
            server.shutdown().awaitTermination(30,TimeUnit.SECONDS);
        }
    }

    private void blockUntilShutdown() throws InterruptedException {
        if (server != null) {
            server.awaitTermination();
        }
    }


    public static void main(String[] args) throws IOException, InterruptedException {
        ServerMain server = new ServerMain(10000);
        server.start();
        server.blockUntilShutdown();
    }
}

4.5 启动Server

image.png

5.Client端编写

package study.grpc;


import io.grpc.Channel;
import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import io.grpc.internal.ClientStream;
import lombok.extern.log4j.Log4j2;
import study.grpc.pojo.GreeterOuterClass.*;
import study.grpc.rpc.GreeterGrpc.*;

import java.util.concurrent.TimeUnit;

import static study.grpc.rpc.GreeterGrpc.newBlockingStub;

/**
 * @Author LynHB
 * @Description : g rpc 客户端入口类
 * @Date 19:56 2020/7/29
 **/
@Log4j2
public class ClientMain {

    private final GreeterBlockingStub blockingStub;
    private final ManagedChannel managedChannel;


    public ClientMain(String ip,int port) {
        this.managedChannel = ManagedChannelBuilder.forTarget(ip+":"+port).usePlaintext().build();
        this.blockingStub = newBlockingStub(this.managedChannel);
        log.info("Connected to server at "+ip+":"+port);

        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            try {
                this.managedChannel.shutdownNow().awaitTermination(5, TimeUnit.SECONDS);

            } catch (InterruptedException e) {
                e.printStackTrace(System.err);
            }
            System.err.println("Client shut down.");
        }));
    }

    private void shutdown() throws InterruptedException {
        this.managedChannel.shutdown().awaitTermination(5L, TimeUnit.SECONDS);
    }

    public static void main(String[] args) throws InterruptedException {
        ClientMain clientMain = new ClientMain("0.0.0.0",10000);

        HelloReply helloReply = clientMain.blockingStub.sayHello(HelloRequest.newBuilder().setName("测试").build());
        log.info(helloReply.getMessage());
        clientMain.shutdown();

    }
}