grpc java helloworld简单demo开发

　　最近google发布了grpc1.0，数据交互使用了protocol buffer，相比之前使用的hession和json序列化方式性能应该提升不少，所有先搞一个grpc的hello world跑一下，项目使用maven搭建，并使用Eclipse开发。

一.使用Eclipse创建maven项目，添加pom配置

1.添加grpc1.0 maven依赖

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <grpc.version>1.4.0</grpc.version><!-- CURRENT_GRPC_VERSION -->  
</properties>

<dependencies>
	<dependency>  
		<groupId>io.grpc</groupId>  
		<artifactId>grpc-netty</artifactId>  
		<version>${grpc.version}</version>  
	</dependency>  
	<dependency>  
		<groupId>io.grpc</groupId>  
		<artifactId>grpc-protobuf</artifactId>  
		<version>${grpc.version}</version>  
	</dependency>  
	<dependency>  
		<groupId>io.grpc</groupId>  
		<artifactId>grpc-stub</artifactId>  
		<version>${grpc.version}</version>  
	</dependency>  
	<dependency>  
		<groupId>io.grpc</groupId>  
		<artifactId>grpc-testing</artifactId>  
		<version>${grpc.version}</version>  
		<scope>test</scope>  
	</dependency>  
	<dependency>  
		<groupId>junit</groupId>  
		<artifactId>junit</artifactId>  
		<version>4.11</version>  
		<scope>test</scope>  
	</dependency>  
	<dependency>  
		<groupId>org.mockito</groupId>  
		<artifactId>mockito-core</artifactId>  
		<version>1.9.5</version>  
		<scope>test</scope>  
	</dependency>
</dependencies>

2.配置protobuf maven插件

        配置了protobuf 插件后，可以自动将.proto文件生成对应的java代码。

<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.xolstice.maven.plugins</groupId>  
			<artifactId>protobuf-maven-plugin</artifactId>  
			<version>0.5.0</version>  
			<configuration>  
				<protocArtifact>com.google.protobuf:protoc:3.3.0:exe:${os.detected.classifier}</protocArtifact>  
				<pluginId>grpc-java</pluginId>  
				<pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>  
			</configuration>  
			<executions>  
				<execution>  
					<goals>  
						<goal>compile</goal>  
						<goal>compile-custom</goal>  
					</goals>  
				</execution>  
			</executions>  
		</plugin>  
	</plugins>  
</build>

　　配置完，整个pom.xml文件内容如下：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.bijian</groupId>
  <artifactId>test-grpc</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>test-grpc</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <grpc.version>1.4.0</grpc.version><!-- CURRENT_GRPC_VERSION -->  
  </properties>

    <dependencies>
        <dependency>  
            <groupId>io.grpc</groupId>  
            <artifactId>grpc-netty</artifactId>  
            <version>${grpc.version}</version>  
        </dependency>  
        <dependency>  
            <groupId>io.grpc</groupId>  
            <artifactId>grpc-protobuf</artifactId>  
            <version>${grpc.version}</version>  
        </dependency>  
        <dependency>  
            <groupId>io.grpc</groupId>  
            <artifactId>grpc-stub</artifactId>  
            <version>${grpc.version}</version>  
        </dependency>  
        <dependency>  
            <groupId>io.grpc</groupId>  
            <artifactId>grpc-testing</artifactId>  
            <version>${grpc.version}</version>  
            <scope>test</scope>  
        </dependency>  
        <dependency>  
            <groupId>junit</groupId>  
            <artifactId>junit</artifactId>  
            <version>4.11</version>  
            <scope>test</scope>  
        </dependency>  
        <dependency>  
            <groupId>org.mockito</groupId>  
            <artifactId>mockito-core</artifactId>  
            <version>1.9.5</version>  
            <scope>test</scope>  
        </dependency>
    </dependencies>
      
    <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.xolstice.maven.plugins</groupId>  
                <artifactId>protobuf-maven-plugin</artifactId>  
                <version>0.5.0</version>  
                <configuration>  
                    <protocArtifact>com.google.protobuf:protoc:3.3.0:exe:${os.detected.classifier}</protocArtifact>  
                    <pluginId>grpc-java</pluginId>  
                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>  
                </configuration>  
                <executions>  
                    <execution>  
                        <goals>  
                            <goal>compile</goal>  
                            <goal>compile-custom</goal>  
                        </goals>  
                    </execution>  
                </executions>  
            </plugin>  
        </plugins>  
	</build>
</project>

 

二.编写proto文件helloworld.proto

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
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;
}

        然后点击pom.xml右击->Run as->Maven install，将会在target/generatedo-sources下生成的对应的java代码，如下所示：

　　将生成的代码拷贝到src/main/java下，如下所示（有几处@java.lang.Override的编译错误，去掉即可）：

 

三.编写grpc 服务端HelloWorldServer.java

package com.bijian.test_grpc;

import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.examples.helloworld.GreeterGrpc;
import io.grpc.examples.helloworld.HelloReply;
import io.grpc.examples.helloworld.HelloRequest;
import io.grpc.stub.StreamObserver;
import java.io.IOException;

public class HelloWorldServer {
	
    private int port = 50051;
    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");
                HelloWorldServer.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 HelloWorldServer server = new HelloWorldServer();
        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("service:"+req.getName());
            HelloReply reply = HelloReply.newBuilder().setMessage(("Hello: " + req.getName())).build();
            responseObserver.onNext(reply);
            responseObserver.onCompleted();
        }
    }
}

 

四.编写grpc 客户端 HelloWorldClient.java

package com.bijian.test_grpc;

import io.grpc.ManagedChannel; 
import io.grpc.ManagedChannelBuilder;
import io.grpc.examples.helloworld.GreeterGrpc; 
import io.grpc.examples.helloworld.HelloReply; 
import io.grpc.examples.helloworld.HelloRequest;
import java.util.concurrent.TimeUnit; 

public class HelloWorldClient {

    private final ManagedChannel channel; 
    private final GreeterGrpc.GreeterBlockingStub blockingStub;

    public HelloWorldClient(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(response.getMessage());

    }
    
    public static void main(String[] args) throws InterruptedException { 
        HelloWorldClient client = new HelloWorldClient("127.0.0.1",50051);
        for(int i=0;i<5;i++){
            client.greet("world:"+i);
        }
    } 
}

 

五.项目完整结构

 

六.项目运行结果

        服务端

service start...
service:world:0
service:world:1
service:world:2
service:world:3
service:world:4
三月 17, 2018 9:30:40 下午 io.grpc.netty.NettyServerTransport notifyTerminated

        客户端

Hello: world:0
Hello: world:1
Hello: world:2
Hello: world:3
Hello: world:4

  

参考文章：http://blog.csdn.net/whzhaochao/article/details/52421867