grpc学习笔记（一）

2024-02-02 23:40:04

grpc

一、开始使用

根据gRPC-Java编译框架的地址我们可以看到具体的操作流程，当然，刚开始第一步时引入grpc的maven依赖

<dependency>
    <groupId>com.google.protobuf</groupId>
    <artifactId>protobuf-java</artifactId>
    <version>3.11.0</version>
</dependency>
<dependency>
    <groupId>com.google.protobuf</groupId>
    <artifactId>protobuf-java-util</artifactId>
    <version>3.11.0</version>
</dependency>
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-netty-shaded</artifactId>
    <version>1.36.0</version>
</dependency>
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-protobuf</artifactId>
    <version>1.36.0</version>
</dependency>
<dependency>
    <groupId>io.grpc</groupId>
    <artifactId>grpc-stub</artifactId>
    <version>1.36.0</version>
</dependency>
<dependency> <!-- necessary for Java 9+ -->
    <groupId>org.apache.tomcat</groupId>
    <artifactId>annotations-api</artifactId>
    <version>6.0.53</version>
    <scope>provided</scope>
</dependency>

下面引入编译插件，引入插件编译的时候，注意下，proto存放位置与该包放在同位置下，它默认会根据proto中设置的package去找，我的proto文件的package是设置的package proto，当然如果要放在其他位置，这个package是需要变化的，不然插件会找不到

<plugin>
    <groupId>org.xolstice.maven.plugins</groupId>
    <artifactId>protobuf-maven-plugin</artifactId>
    <version>0.6.1</version>
    <configuration>
        <protocArtifact>com.google.protobuf:protoc:3.12.0:exe:${os.detected.classifier}</protocArtifact>
        <pluginId>grpc-java</pluginId>
        <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.36.0:exe:${os.detected.classifier}</pluginArtifact>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>compile</goal>
                <goal>compile-custom</goal>
            </goals>
        </execution>
    </executions>
</plugin>
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
        <source>8</source>
        <target>8</target>
        <encoding>utf-8</encoding>
    </configuration>
</plugin>

完整的pom.xml

<?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>ProtocolBuffer</groupId>
    <artifactId>ProtocolBuffer</artifactId>
    <version>1.0-SNAPSHOT</version>
    <build>
        <extensions>
            <extension>
                <groupId>kr.motd.maven</groupId>
                <artifactId>os-maven-plugin</artifactId>
                <version>1.6.2</version>
            </extension>
        </extensions>
        <plugins>
            <plugin>
                <groupId>org.xolstice.maven.plugins</groupId>
                <artifactId>protobuf-maven-plugin</artifactId>
                <version>0.6.1</version>
                <configuration>
                    <protocArtifact>com.google.protobuf:protoc:3.12.0:exe:${os.detected.classifier}</protocArtifact>
                    <pluginId>grpc-java</pluginId>
                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.36.0:exe:${os.detected.classifier}</pluginArtifact>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>compile-custom</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>8</source>
                    <target>8</target>
                    <encoding>utf-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>3.11.0</version>
        </dependency>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java-util</artifactId>
            <version>3.11.0</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.6</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-netty-shaded</artifactId>
            <version>1.36.0</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-protobuf</artifactId>
            <version>1.36.0</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-stub</artifactId>
            <version>1.36.0</version>
        </dependency>
        <dependency> <!-- necessary for Java 9+ -->
            <groupId>org.apache.tomcat</groupId>
            <artifactId>annotations-api</artifactId>
            <version>6.0.53</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.1</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>
</project>

搭建完成后，开始进行简单的demo测试

创建一个proto文件grpcDemo.proto

syntax = "proto3";
package proto;
option java_package = "com.protocol.grpcdemo";
option java_outer_classname = "GrpcDemo";
message req{
  string msg = 1;
}

message res{
  string resMsg = 1;
}
//这是服务，会自动生成服务器端的Service与客户端的调用的Stub。也就是说，我们在
service sayHelloRpc{
  rpc sayHello(req) returns (res){};
}

点击install生成代码

将上面两个类复制到src中的对应目录下，就可以开始写服务器端和客户端了。

服务器代码TestDemo.java

package com.protocol.grpcdemo;

import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;
import org.junit.Test;

import java.io.IOException;

/**
 * @author chengfei.liu
 * @since 2021/2/28 11:06
 */
public class TestDemo {
    private Server server;
    public void test() throws IOException, InterruptedException {
        int port = 10086;
        System.out.println("服务器启动了");
        //初始化服务器，绑定端口，并添加服务，服务是接口，需要自己实现里面的逻辑
         server = ServerBuilder.forPort(port).addService(new sayHelloRpcGrpc.sayHelloRpcImplBase() {
            @Override
            public void sayHello(GrpcDemo.req request, StreamObserver<GrpcDemo.res> responseObserver) {
                //主要业务逻辑
                System.out.println(request.getMsg());
                //创建需要返回的参数实体
                GrpcDemo.res.Builder builder = GrpcDemo.res.newBuilder();
                builder.setResMsg("这是服务器相应的信息");
                GrpcDemo.res build = builder.build();
                //发送
                responseObserver.onNext(build);
                //关闭连接
                responseObserver.onCompleted();
            }
        }).build().start();
//         server.awaitTermination();

        //关闭服务器
        Runtime.getRuntime().addShutdownHook(new Thread(){
            @Override
            public void run() {
                super.run();
                System.out.println("服务器即将关闭");
                TestDemo.this.stop();
                System.out.println("服务器已关闭");
            }
        });
    }
    private void stop(){
        if(server!=null){
            server.shutdownNow();
        }
    }
    //设置堵塞态，一直再等待客户端的连接
    private void blockUtilShutDown() throws InterruptedException {
        if(server!=null){
            server.awaitTermination();
        }
    }

    public static void main(String[] args) throws Exception {
        TestDemo testDemo = new TestDemo();
        testDemo.test();
        testDemo.blockUtilShutDown();
    }
}

客户端代码

package com.protocol.grpcdemo;

import io.grpc.CallOptions;
import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;

import java.util.concurrent.TimeUnit;

/**
 * @author chengfei.liu
 * @since 2021/2/28 11:31
 */
public class TestDemoClient {
    //添加通道，用于连接客户端与服务器，方便传输，可以了解一下NIO
    private ManagedChannel channel;
    //这是主要客户端工具，里面封装了客户端可以调用的方法、设置选项等等
    private sayHelloRpcGrpc.sayHelloRpcBlockingStub blockingStub;
    //创建客户端
    public void sayHelloClient(String address,int port){
        //利用ManagedChannelBuilder初始化一个通道，进行连接到服务器，注意：如果需要使用字符串传输，需要添加usePlaintext，否则会出现异常HTTP/2 client preface string missing or corrupt. Hex dump for received bytes: 504f5354202f68656
        channel = ManagedChannelBuilder.forAddress(address,port).usePlaintext().build();
        //初始化sayHelloRpcGrpc的客户端工具，并将通道添加到其中
        blockingStub = sayHelloRpcGrpc.newBlockingStub(channel);
    }
    //延迟关闭
    public void shudown() throws InterruptedException {
        channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);
    }
    //RPC调用
    public void query(String msg){
        //创建调用参数实体
        GrpcDemo.req build = GrpcDemo.req.newBuilder().setMsg(msg).build();
        //调用远程接口并得到返回值
        GrpcDemo.res res = blockingStub.sayHello(build);
        System.out.println(res.getResMsg());
    }

    public static void main(String[] args) {
        TestDemoClient testDemoClient = null;
        try {
            testDemoClient = new TestDemoClient();
            testDemoClient.sayHelloClient("127.0.0.1", 10086);
            testDemoClient.query("这是客户端发来的信息");
        }catch (Exception e) {
            assert testDemoClient!=null;
            try {
                testDemoClient.shudown();
            }catch (InterruptedException ex){
                ex.printStackTrace();
            }
        }

    }
}

结果

码农公寓

一、开始使用

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