gRPC-Java实践
1.新建一个Maven工程，添加gRPC相关依赖
<!-- https://mvnrepository.com/artifact/io.grpc/grpc-stub -->
<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-all</artifactId>
<version>1.20.0</version>
</dependency>
2.添加protocol buffers 编译插件
<build>
<extensions>
<extension>
<groupId>kr.motd.maven</groupId>
<artifactId>os-maven-plugin</artifactId>
<version>1.4.1.Final</version>
</extension>
</extensions>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.xolstice.maven.plugins</groupId>
<artifactId>protobuf-maven-plugin</artifactId>
<version>0.6.1</version>
<configuration>
<protocArtifact>com.google.protobuf:protoc:3.0.0:exe:${os.detected.classifier}</protocArtifact>
<pluginId>grpc-java</pluginId>
<pluginArtifact>io.grpc:protoc-gen-grpc-java:0.15.0:exe:${os.detected.classifier}</pluginArtifact>
<protocExecutable>/Users/sgf/Documents/yang/MyWork/protoc-3.7.1-osx-x86_64/bin/protoc</protocExecutable>
</configuration>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>compile-custom</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
2.1注意
第二个框框中的地址是我本地protoc的编译执行程序所在地址
这是我的文件结构，重要的文件都框出来了
3.编写.proto文件
syntax = "proto3";
option java_multiple_files = true;
option java_package = "com.page.awesome.dto.proto";
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) {
}
// Sends another greeting
rpc SayHelloAgain (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.编译
图中的两个都需要，然后就完成了。
5.创建HelloWorldClient和HelloWorldServer
/*
* Copyright 2015 The gRPC Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.page.awesome.hello;
import com.page.awesome.dto.proto.GreeterGrpc;
import com.page.awesome.dto.proto.HelloReply;
import com.page.awesome.dto.proto.HelloRequest;
import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import io.grpc.StatusRuntimeException;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* A simple client that requests a greeting from the {@link HelloWorldServer}.
*/
public class HelloWorldClient {
private static final Logger logger = Logger.getLogger(HelloWorldClient.class.getName());
private final ManagedChannel channel;
private final GreeterGrpc.GreeterBlockingStub blockingStub;
/** Construct client connecting to HelloWorld server at {@code host:port}. */
public HelloWorldClient(String host, int port) {
this(ManagedChannelBuilder.forAddress(host, port)
// Channels are secure by default (via SSL/TLS). For the example we disable TLS to avoid
// needing certificates.
.usePlaintext()
.build());
}
/** Construct client for accessing HelloWorld server using the existing channel. */
HelloWorldClient(ManagedChannel channel) {
this.channel = channel;
blockingStub = GreeterGrpc.newBlockingStub(channel);
}
public void shutdown() throws InterruptedException {
channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);
}
/** Say hello to server. */
public void greet(String name) {
logger.info("client request ==============" + name + " ...");
HelloRequest request = HelloRequest.newBuilder().setName(name).build();
HelloReply response;
try {
response = blockingStub.sayHello(request);
} catch (StatusRuntimeException e) {
logger.log(Level.WARNING, "RPC failed: {0}", e.getStatus());
return;
}
logger.info("response: ===============" + 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 {
HelloWorldClient client = new HelloWorldClient("localhost", 50051);
try {
/* Access a service running on the local machine on port 50051 */
String user = "world===============";
if (args.length > 0) {
user = args[0]; /* Use the arg as the name to greet if provided */
}
client.greet(user);
} finally {
client.shutdown();
}
}
}
/*
* Copyright 2015 The gRPC Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.page.awesome.hello;
import com.page.awesome.dto.proto.GreeterGrpc;
import com.page.awesome.dto.proto.HelloReply;
import com.page.awesome.dto.proto.HelloRequest;
import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;
import java.io.IOException;
import java.util.logging.Logger;
/**
* Server that manages startup/shutdown of a {@code Greeter} server.
*/
public class HelloWorldServer {
private static final Logger logger = Logger.getLogger(HelloWorldServer.class.getName());
private Server server;
private void start() throws IOException {
/* The port on which the server should run */
int port = 50051;
server = ServerBuilder.forPort(port)
.addService(new GreeterImpl())
.build()
.start();
logger.info("Server started, listening on " + port);
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");
HelloWorldServer.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 HelloWorldServer server = new HelloWorldServer();
server.start();
server.blockUntilShutdown();
}
static class GreeterImpl extends GreeterGrpc.GreeterImplBase {
@Override
public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
HelloReply reply = HelloReply.newBuilder().setMessage("Hello ++++++++++++++++" + req.getName()).build();
responseObserver.onNext(reply);
responseObserver.onCompleted();
}
}
}
6.运行
先运行HelloWorldServer，然后运行HelloWorldClient
