gRPC学习(1)

编程语言 2018-08-21 06:44:37 阅读次数: 0

gRpc的基本定义

服务定义

正如其他 RPC 系统，gRPC 基于如下思想：定义一个服务， 指定其可以被远程调用的方法及其参数和返回类型。gRPC 默认使用 protocol buffers 作为接口定义语言，来描述服务接口和有效载荷消息结构。如果有需要的话，可以使用其他替代方案。
Protocol Buffers 语法

.proto文件

syntax = "proto3";//选择语法 proto2 和 proto3 选择

option java_multiple_files = true;
option java_package = "io.grpc.wzc.helloworld";//生成文件的包名
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

// 定义服务
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}//定义接口
}

// 请求的内容
message HelloRequest {
  string name = 1;// 这里的1不可以随便改变
}

// The response message containing the greetings
message HelloReply {
  string message = 1;
}

使用Java创建一个简单RPC

  1. 创建项目
    首先创建一个空的maven项目
    这里写图片描述

  2. maven构造

<?xml version="1.0" encoding="UTF-8"?>
<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.wzc</groupId>
    <artifactId>grpcDemo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <grpc.version>1.14.0</grpc.version><!-- CURRENT_GRPC_VERSION -->
        <protobuf.version>3.5.1</protobuf.version>
        <protoc.version>3.5.1-1</protoc.version>
        <netty.tcnative.version>2.0.7.Final</netty.tcnative.version>
        <!-- required for jdk9 -->
        <maven.compiler.source>1.6</maven.compiler.source>
        <maven.compiler.target>1.6</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-netty-shaded</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>${grpc.version}</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-alts</artifactId>
            <version>${grpc.version}</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-testing</artifactId>
            <version>${grpc.version}</version>
            <scope>test</scope>
        </dependency>

        <!-- Used in HelloWorldServerTls -->
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-netty</artifactId>
            <version>${grpc.version}</version>
        </dependency>
        <dependency>
            <groupId>io.netty</groupId>
            <artifactId>netty-tcnative-boringssl-static</artifactId>
            <version>${netty.tcnative.version}</version>
        </dependency>

        <dependency>
            <groupId>com.google.api.grpc</groupId>
            <artifactId>proto-google-common-protos</artifactId>
            <version>1.0.0</version>
        </dependency>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java-util</artifactId>
            <version>${protobuf.version}</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>1.9.5</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <extensions>
            <extension>
                <groupId>kr.motd.maven</groupId>
                <artifactId>os-maven-plugin</artifactId>
                <version>1.4.1.Final</version>
            </extension>
        </extensions>
        <plugins>
            <plugin>
                <groupId>org.xolstice.maven.plugins</groupId>
                <artifactId>protobuf-maven-plugin</artifactId>
                <version>0.5.0</version>
                <configuration>
                    <protocArtifact>com.google.protobuf:protoc:3.3.0:exe:${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>

引入.proto文件
这里写图片描述

打包mvn install
这里写图片描述

生成文件
这里写图片描述

复制到项目中
这里写图片描述

服务器端代码

package io.grpc.wzc.helloworld;

import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;

import java.io.IOException;

public class TestServer {
    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();
        System.out.println("测试开始");
        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");
                TestServer.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 TestServer server = new TestServer();
        server.start();
        server.blockUntilShutdown();
    }

    static class GreeterImpl extends GreeterGrpc.GreeterImplBase {

        @Override
        public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
            HelloReply reply = HelloReply.newBuilder().setMessage("shuaige " + req.getName()).build();
            responseObserver.onNext(reply);
            responseObserver.onCompleted();
        }
    }

}

客户端代码

package io.grpc.wzc.helloworld;

import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import io.grpc.StatusRuntimeException;

import java.util.concurrent.TimeUnit;
import java.util.logging.Level;

public class TestClient {
//    private static final Logger logger = Logger.getLogger(TestClient.class.getName());

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

    /** Construct client connecting to HelloWorld server at {@code host:port}. */
    public TestClient(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. */
    TestClient(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) {
        System.out.println("Will try to greet " + name + " ...");
        HelloRequest request = HelloRequest.newBuilder().setName(name).build();
        HelloReply response;
        try {
            response = blockingStub.sayHello(request);
        } catch (StatusRuntimeException e) {
            System.out.println(Level.WARNING);
            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 {
        TestClient client = new TestClient("localhost", 50051);
        try {
            /* Access a service running on the local machine on port 50051 */
            String user = "weizecheng";
            if (args.length > 0) {
                user = args[0]; /* Use the arg as the name to greet if provided */
            }
            client.greet(user);
        } finally {
            client.shutdown();
        }
    }

}

测试开始

启动服务端

这里写图片描述

启动客户端去调用服务端代码

这里写图片描述

核心代码

服务器端

在服务器端实现GreeterImpl

    static class GreeterImpl extends GreeterGrpc.GreeterImplBase {

        @Override
        public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
            HelloReply reply = HelloReply.newBuilder().setMessage("shuaige " + req.getName()).build();
            responseObserver.onNext(reply);
            responseObserver.onCompleted();
        }
    }

同时启动服务

    private void start() throws IOException {
        /* The port on which the server should run */
        int port = 50051; //监听的端口号
        server = ServerBuilder.forPort(port) 
                .addService(new GreeterImpl()) //增加服务 在spring中可以通过IOC注入
                .build()
                .start();
        System.out.println("测试开始");
        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");
                TestServer.this.stop();
                System.err.println("*** server shut down");
            }
        });
    }

客户端

调用方法 

   public void greet(String name) {
        System.out.println("Will try to greet " + name + " ...");
        HelloRequest request = HelloRequest.newBuilder().setName(name).build();
        HelloReply response;
        try {
            response = blockingStub.sayHello(request);
        } catch (StatusRuntimeException e) {
            System.out.println(Level.WARNING);
            return;
        }
        System.out.println("Greeting: " + response.getMessage());
    }

根据Host和Port获取服务端 获取通道 通过通道获取阻塞存根

  public TestClient(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. */
    TestClient(ManagedChannel channel) {
        this.channel = channel;
        blockingStub = GreeterGrpc.newBlockingStub(channel);
    }

gRPC定义了四种service

简单RPC

客户端使用 Stub 发送请求到服务器并等待响应返回，就像平常的函数调用一样，这是一个阻塞型的调用

 rpc SayHello (HelloRequest) returns (HelloReply) {}//定义接口

服务器端流式 RPC

客户端发送请求到服务器，拿到一个流去读取返回的消息序列。客户端读取返回的流，直到里面没有任何消息。从例子中可以看出，通过在响应类型前插入 stream 关键字，可以指定一个服务器端的流方法

rpc ListFeatures(Rectangle) returns (stream Feature) {}

客户端流式 RPC

客户端写入一个消息序列并将其发送到服务器，同样也是使用流。一旦客户端完成写入消息，它等待服务器完成读取返回它的响应。通过在请求类型前指定 stream 关键字来指定一个客户端的流方法

rpc RecordRoute(stream Point) returns (RouteSummary) {}

双向流式 RPC

双方使用读写流去发送一个消息序列。两个流独立操作，因此客户端和服务器可以以任意喜欢的顺序读写：比如， 服务器可以在写入响应前等待接收所有的客户端消息，或者可以交替的读取和写入消息，或者其他读写的组合。每个流中的消息顺序被预留。你可以通过在请求和响应前加 stream 关键字去制定方法的类型

rpc RouteChat(stream RouteNote) returns (stream RouteNote) {}

以上内容参考gRPC 官方文档

猜你喜欢

转载自blog.csdn.net/qq_35138150/article/details/81837075
今日推荐
中国码农的“35岁魔咒”
蘭雅 CorelDRAW 插件 2024.5.1 国际劳动节版，免费下载
Arc Browser for Windows 1.0 正式 GA
90后程序员开发视频搬运软件、不到一年获利超 700 万，结局很刑！
《美国对全球网络空间安全与发展的威胁和破坏》报告发布
周排行
[编程题]学英语
[codeforces 1288A] Deadline 约数+模
Python的web开发
Docker在Centos 7上的部署
python编码
解决Ubuntu16.04 fatal error: json/json.h: No such file or directory
mysql并发插入
rest接口如何适应jsonp的方案
linux 终端上网设置
高数——等号两边同时求导、积分的解释
每日归档
更多
2024-05-04(7)
2024-05-03(19)
2024-05-02(0)
2024-05-01(4)
2024-04-30(1)
2024-04-29(40)
2024-04-28(0)
2024-04-27(56)
2024-04-26(39)
2024-04-25(22)

代码天地 © 2018 codetd.com

境外服务器   最新电视剧2022