python与java使用grpc以及java作为客户端调用python服务的小demo
python使用grpc
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使用的工具：python3.8 pycharm2020.2
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安装环境：
python -m pip install grpcio python -m pip install grpcio-tools python -m pip install protobuf
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建立一个python项目，创建以下文件
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写下helloworld.proto,进行编译
helloworld.proto
syntax = "proto3"; option java_package = "com.grpc.test"; package helloworld; 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; }输入命令对helloworld.proto进行编译，生成了helloworld_pb2.py和helloworld_pb2_grpc.py
python -m grpc_tools.protoc -I=. --python_out=. -- grpc_python_out=. helloworld.proto -
写入service.py和client.py
service.py
import time from concurrent import futures import grpc import helloworld_pb2 import helloworld_pb2_grpc _ONE_DAY_IN_SERVICE = 60 * 60 * 24 IP = "[::]:50051" class service(helloworld_pb2_grpc.GreeterServicer): def SayHello(self, request, context): txt = request.name return helloworld_pb2.HelloReply(message='hello2 {msg}'.format(msg=txt)) def serve(): grpcServer = grpc.server(futures.ThreadPoolExecutor(max_workers=4)) helloworld_pb2_grpc.add_GreeterServicer_to_server(service(), grpcServer) grpcServer.add_insecure_port(IP) grpcServer.start() print("server start success") try: while True: time.sleep(_ONE_DAY_IN_SERVICE) except KeyboardInterrupt: grpcServer.stop(0) if __name__ == '__main__': serve()client.py
import grpc import helloworld_pb2 import helloworld_pb2_grpc IP = 'localhost:50051' def run(): channel = grpc.insecure_channel(IP) stub = helloworld_pb2_grpc.GreeterStub(channel=channel) response = stub.SayHello(helloworld_pb2.HelloRequest(name='luo')) print("recevied: " + response.message) if __name__ == '__main__': run()
6.先运行service.py,再运行client.py,客户端和服务器端通过端口50051成功通信
java中使用grpc
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使用的工具：java 1.8.0 idea
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首先建立一个maven工程，并在maven工程下src/main目录下建立proto文件夹（这个proto文件夹只能在这里建立，是为了下面更好的编译，减少不必要的麻烦），具体目录如下：
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写入helloworld.proto文件，这个文件与python中使用的要是同一个
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修改pom.xml，引入依赖和插件
<dependencies>
<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-netty-shaded</artifactId>
<version>1.16.1</version>
</dependency>
<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-protobuf</artifactId>
<version>1.16.1</version>
</dependency>
<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-stub</artifactId>
<version>1.16.1</version>
</dependency>
</dependencies>
<build>
<extensions>
<extension>
<groupId>kr.motd.maven</groupId>
<artifactId>os-maven-plugin</artifactId>
<version>1.5.0.Final</version>
</extension>
</extensions>
<plugins>
<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:${os.detected.classifier}</protocArtifact>
<pluginId>grpc-java</pluginId>
<pluginArtifact>io.grpc:protoc-gen-grpc-java:1.16.1:exe:${os.detected.classifier}</pluginArtifact>
</configuration>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>compile-custom</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
- 在idea的终端输入 mvn compile，会在target目录下生成如下文件：GreeterGrpc.java和Helloworld.java
- 将上面的文件剪切到如下目录（目录是根据proto文件新建的）
- 再创建一个服务端处理消息的类SayHelloImpl，实现我们服务定义的生成的服务接口，做我们的服务的实际的“工作”。
package com.grpc.test;
import io.grpc.stub.StreamObserver;
/**
* @author luoaojin
* @CreateTime 2018-11-14
* @Description
*/
public class SayHelloImpl extends GreeterGrpc.GreeterImplBase {
@Override
public void sayHello(Helloworld.HelloRequest request, StreamObserver<Helloworld.HelloReply> responseObserver) {
// 这一行一定要删除，否则会提示你没有实现这个方法。
// super.sayHello(request, responseObserver);
System.out.println(request.getName());
Helloworld.HelloReply data = Helloworld.HelloReply.newBuilder().setMessage("Hello " + request.getName()).build();
responseObserver.onNext(data);
responseObserver.onCompleted();
}
}
- 编写客户端Client.java和服务端DefinedServer.java
Client.java
package com.grpc.test;
import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import io.grpc.StatusRuntimeException;
import java.util.concurrent.TimeUnit;
/**
* @author luoaojin
* @CreateTime 2018-11-14
* @Description
*/
public class Client {
private final ManagedChannel channel;
private final GreeterGrpc.GreeterBlockingStub blockingStub;
/**
* Construct client connecting to HelloWorld server at {@code host:port}.
*/
public Client(String host, int port) {
channel = ManagedChannelBuilder.forAddress(host, port)
.usePlaintext()
.build();
blockingStub = GreeterGrpc.newBlockingStub(channel);
}
public void shutdown() throws InterruptedException {
channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);
}
/**
* Say hello to server.
*/
public void greet(String name) {
Helloworld.HelloRequest request = Helloworld.HelloRequest.newBuilder().setName(name).build();
Helloworld.HelloReply response;
try {
response = blockingStub.sayHello(request);
} catch (StatusRuntimeException e) {
System.out.println("RPC failed: {0}"+ e.getStatus());
return;
}
System.out.println(("Greeting: " + response.getMessage()));
}
/**
* Greet server. If provided, the first element of {@code args} is the name to use in the
* greeting.
*/
public static void main(String[] args) throws Exception {
Client client = new Client("localhost", 50051);
try {
String user = "luo";
if (args.length > 0) {
user = args[0];
}
client.greet(user);
} finally {
client.shutdown();
}
}
}
DefinedServer
package com.grpc.test;
import io.grpc.Server;
import io.grpc.ServerBuilder;
import java.io.IOException;
/**
* @author luoaojin
* @CreateTime 2018-11-14
* @Description
*/
public class DefinedServer {
private Server server;
private void start() throws IOException {
server = ServerBuilder.forPort(50051)//服务端只用指定端口号
.addService(new SayHelloImpl())
.build()
.start();
Runtime.getRuntime().addShutdownHook(new Thread() {
@Override
public void run() {
// Use stderr here since the logger may have been reset by its JVM shutdown hook.
System.err.println("*** shutting down gRPC server since JVM is shutting down");
this.stop();
System.err.println("*** server shut down");
}
});
}
private void stop() {
if (server != null) {
server.shutdown();
}
}
/**
* Await termination on the main thread since the grpc library uses daemon threads.
*/
private void blockUntilShutdown() throws InterruptedException {
if (server != null) {
server.awaitTermination();
}
}
/**
* Main launches the server from the command line.
*/
public static void main(String[] args) throws IOException, InterruptedException {
final DefinedServer server = new DefinedServer();
server.start();
server.blockUntilShutdown();
}
}
- 先运行服务器端,再运行客户端,客户端和服务器端通过端口50051成功通信（注意端口占用问题）
java客户端调用python服务端
运行java的客户端和python的服务端即可，二者即可通信