grpc java helloworld简单demo开发

旧城等待， 2022-04-06 12:40 413阅读 0赞

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>  
    </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>  
      </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：

![af8d35bf-da11-34c5-8fbf-be0a3632c164.png][]  
　　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）：

![d8e14031-7ba3-304d-8d4f-14948cd4edea.png][]

**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**

![9322c70b-64e1-38cb-bc24-cfc34af2ab2d.png][]

**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][http_blog.csdn.net_whzhaochao_article_details_52421867]

[af8d35bf-da11-34c5-8fbf-be0a3632c164.png]: /images/20220406/b4b2376323be4ece88dea82167b6b67b.png
[d8e14031-7ba3-304d-8d4f-14948cd4edea.png]: /images/20220406/640a96237fa44ab793e2041cbbef0765.png
[9322c70b-64e1-38cb-bc24-cfc34af2ab2d.png]: /images/20220406/d90e6cc758e64de5bdf0fde797ebb688.png
[http_blog.csdn.net_whzhaochao_article_details_52421867]: http://blog.csdn.net/whzhaochao/article/details/52421867