grpc（java）入门使用

1.最近由于目前公司微服务使用到grpc可是grpc一般使用在go语言上，因此国内基本没有什么关于grpc在java的完整教程，因此我也对grpc进行了一些资料查找和学习，只能说可以使用，原理就不深入了。

2.grpc官网
3.创建父工程，作为如果你学习到了grpc还没使用父工程进行项目创建，建议可以现去学习一下关于父工程统一定义版本等相关学习
4.创建工程引入依赖

父工程pom依赖


```xml
```go
<?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.minjiang</groupId>
    <artifactId>SecondGrpc</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>grpcDemo</module>
    </modules>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <grpc.version>1.34.1</grpc.version>
        <protobuf.version>3.12.0</protobuf.version>
        <protoc.version>3.12.0</protoc.version>
        <maven.cpmplier.source>1.8</maven.cpmplier.source>
        <maven.cpmplier.target>1.8</maven.cpmplier.target>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>io.grpc</groupId>
                <artifactId>grpc-bom</artifactId>
                <version>${grpc.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>com.google.protobuf</groupId>
                <artifactId>protobuf-java-util</artifactId>
                <version>${protobuf.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>

    </dependencyManagement>

    <build>
        <extensions>
            <extension>
                <groupId>kr.motd.maven</groupId>
                <artifactId>os-maven-plugin</artifactId>
                <version>1.6.2</version>
            </extension>
        </extensions>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.xolstice.maven.plugins</groupId>
                <artifactId>protobuf-maven-plugin</artifactId>
                <version>0.6.1</version>
                <configuration>
                    <protocArtifact>com.google.protobuf:protoc:${protoc.version}:exe:${os.detected.classifier}</protocArtifact>
                    <pluginId>grpc-java</pluginId>
                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
                    <protoSourceRoot>src/main/resources/proto</protoSourceRoot>
                </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>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

子工程pom.xml


```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">
    <parent>
        <artifactId>SecondGrpc</artifactId>
        <groupId>com.minjiang</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>grpcDemo</artifactId>

    <dependencies>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-stub</artifactId>
        </dependency>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java-util</artifactId>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-netty-shaded</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-protobuf</artifactId>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-stub</artifactId>
        </dependency>
    </dependencies>
    <build>
        <extensions>
            <extension>
                <groupId>kr.motd.maven</groupId>
                <artifactId>os-maven-plugin</artifactId>
                <version>1.6.2</version>
            </extension>
        </extensions>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.xolstice.maven.plugins</groupId>
                <artifactId>protobuf-maven-plugin</artifactId>
                <version>0.6.1</version>
                <configuration>
                    <protocArtifact>com.google.protobuf:protoc:${protoc.version}:exe:${os.detected.classifier}</protocArtifact>
                    <pluginId>grpc-java</pluginId>
                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
                    <protoSourceRoot>src/main/resources/proto</protoSourceRoot>
                </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>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

5.首先在resouce下创建你的proto文件夹（系统默认设置），并且创建.proto文件
在这里插入图片描述

6.add.proto文件

syntax = "proto3";

package grpcDemo;
option java_package = "a.b.c";
option java_outer_classname = "AddServiceProto";
option java_multiple_files = true;


service AddService{
    rpc add(AddRequest) returns(AddReply){}
}

 message AddRequest{
   int32 a = 1;
   int32 b = 2;
 }

  message AddReply{
    int32 res = 1;
  }

7.install生成文件
在这里插入图片描述
8.intsall生成会在target中出现
下图为我们主要生成的service

9.生成之后我们进行配置服务端和客户端的测试，如下图新建两个java文件

10.服务端文件

package a.b.c;
import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;

import java.io.IOException;

import static a.b.c.AddServiceGrpc.getAddMethod;
import static io.grpc.stub.ServerCalls.asyncUnimplementedUnaryCall;

/**
 * @auther guannw
 * @create 2021/6/28 21:05
 */
public class AddServer extends AddServiceGrpc.AddServiceImplBase {

    public static void main(String[] args) throws IOException {
        ServerBuilder.forPort(9999)//设置端口
                .addService(new AddServer())// 添加服务
                .build() //创建服务
                .start();//开始服务
        System.out.println("server start at 9999");
        while (true){

        }
    }
    public void add(AddRequest request, StreamObserver<AddReply> responseObserver) {
//        asyncUnimplementedUnaryCall(getAddMethod(), responseObserver);
        int res = myAdd(request.getA(),request.getB());
        //返回值
        responseObserver.onNext(AddReply.newBuilder().setRes(res).build());
        //结束
        responseObserver.onCompleted();
    }

    private int myAdd(int a , int b){
        return  a + b ;
    }
}

代码解析如下图
在这里插入图片描述

11.客户端代码

package a.b.c;

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

/**
 * @auther guannw
 * @create 2021/6/28 21:15
 */
public class AddClient {
    ManagedChannel channel;
    AddServiceGrpc.AddServiceBlockingStub  stub;
    public static void main(String[] args) {
        int a = 12;
        int b = 13;
        AddClient addClient = new AddClient();

        AddReply reply = addClient.stub.add(AddRequest.newBuilder().setA(a).setB(b).build());
        System.out.println(reply.getRes());

    }

    public AddClient(){
         channel = ManagedChannelBuilder
                .forAddress("127.0.0.1",9999)
                 .usePlaintext() //使用纯文本类型
                .build();
         stub =
                 AddServiceGrpc.newBlockingStub(channel);
    }
}

代码解析
在这里插入图片描述
12.测试先启动服务端在启动客户端即可，这里就不演示了

grpc（java）入门使用

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