springboot2 + grpc

项目情况：

springboot: 2.2.2

grpc-spring-boot-starter: 2.6.1.RELEASE

项目目录：

mypro:

　　- person  - grpc服务端

　　- lib - 公共库

　　- device - grpc客户端

项目建立可参考：项目建立部分可参考我另一篇随笔的项目建立部分：

https://www.cnblogs.com/SamNicole1809/p/12200875.html

步骤一：引入依赖

我是都在lib模块引入的：

        <dependency>
            <groupId>net.devh</groupId>
            <artifactId>grpc-spring-boot-starter</artifactId>
            <version>2.6.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>net.devh</groupId>
            <artifactId>grpc-server-spring-boot-starter</artifactId>
            <version>2.6.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>net.devh</groupId>
            <artifactId>grpc-client-spring-boot-starter</artifactId>
            <version>2.6.1.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-stub</artifactId>
            <version>1.26.0</version>
        </dependency>

        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-protobuf</artifactId>
            <version>1.26.0</version>
        </dependency>

    <properties>
        <java.version>1.8</java.version>
        <os.plugin.version>1.6.2</os.plugin.version>
        <grpc.version>1.26.0</grpc.version>
        <protoc.version>3.11.0</protoc.version>
        <protobuf.plugin.version>0.6.1</protobuf.plugin.version>
        <skipTests>true</skipTests>
    </properties>

    <build>
        <extensions>
            <extension>
                <groupId>kr.motd.maven</groupId>
                <artifactId>os-maven-plugin</artifactId>
                <version>${os.plugin.version}</version>
            </extension>
        </extensions>
        <plugins>
            <plugin>
                <groupId>org.xolstice.maven.plugins</groupId>
                <artifactId>protobuf-maven-plugin</artifactId>
                <version>${protobuf.plugin.version}</version>
                <extensions>true</extensions>
                <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>${project.basedir}/src/main/proto</protoSourceRoot>
                    <outputDirectory>${project.basedir}/src/main/java</outputDirectory>
                    <clearOutputDirectory>false</clearOutputDirectory>
                    <!-- for more https://www.xolstice.org/protobuf-maven-plugin/compile-mojo.html -->
                </configuration>
                <executions>
                    <execution>
                        <!-- run mvn compile -->
                        <phase>compile</phase>
                        <goals>
                            <!-- produce OuterClass -->
                            <goal>compile</goal>
                            <!-- produce Grpc class -->
                            <goal>compile-custom</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

person模块引入：

        <dependency>
            <groupId>net.devh</groupId>
            <artifactId>grpc-server-spring-boot-starter</artifactId>
            <version>2.6.1.RELEASE</version>
        </dependency>

person的application.yml

grpc:
  server:
    port: 9898

device模块引入：

        <dependency>
            <groupId>net.devh</groupId>
            <artifactId>grpc-client-spring-boot-starter</artifactId>
            <version>2.6.1.RELEASE</version>
        </dependency>

device的application.yml

grpc:
  client:
    person:
      address: 'static://127.0.0.1:9898'
      enableKeepAlive: true
      keepAliveWithoutCalls: true
      negotiationType: plaintext

步骤二：生成proto文件

在lib的main目录下新建文件夹proto，再在文件夹中新建文件mypro.proto，文件名可随意。

mypro.proto文件内容：

syntax = "proto3";

option java_package = "com.sam.lib";
option java_multiple_files = true;
option java_outer_classname = "MyproRpcProto";

service MyproRpcService {
    rpc getUser (GrpcStringRequest) returns (GrpcStringResponse) {}
}

message GrpcStringRequest {
    string str = 1;
}

message GrpcStringResponse {
    string str = 1;
}

 安装完相关依赖后，maven中lib的Plugins目录下找到protobug，依次执行compile和compile-custom

执行时需要下载，下载速度比较慢，第二次就很快了，下载完执行如果出错，多半是proto文件内容的问题。

执行成功后会出现如下文件：

utils是我自己建的，主要是下面那些。

步骤三：给person和device增加lib扫描，使其能够引用lib中的所有文件，lib和自己都要加，person同理。

@SpringBootApplication
@ComponentScan({"com.sam.lib.*", "com.sam.device.*"})
public class DeviceApplication {
    public static void main(String[] args) {
        SpringApplication.run(DeviceApplication.class, args);
    }
}

步骤四：服务端代码

import com.sam.lib.GrpcStringRequest;
import com.sam.lib.GrpcStringResponse;
import com.sam.lib.MyproRpcServiceGrpc;
import io.grpc.netty.shaded.io.netty.util.internal.StringUtil;
import io.grpc.stub.StreamObserver;
import net.devh.boot.grpc.server.service.GrpcService;

import java.util.UUID;

@GrpcService
public class PersonGrpcService extends MyproRpcServiceGrpc.MyproRpcServiceImplBase {
    @Override
    public void getUser(GrpcStringRequest request, StreamObserver<GrpcStringResponse> responseObserver) {
        String name = request.getStr();  // 接收请求的内容
        // 定义返回的内容
        GrpcStringResponse response = GrpcStringResponse.newBuilder().setStr("").build();
        // 如果请求正确，返回name和uuid，不正确返回空字符串
        if (!StringUtil.isNullOrEmpty(name)) {
            String result = name + "--" + UUID.randomUUID().toString();
            response = GrpcStringResponse.newBuilder().setStr(result).build();
        }
        responseObserver.onNext(response);
        responseObserver.onCompleted();
    }
}

步骤五：客户端代码

import com.sam.lib.GrpcStringRequest;
import com.sam.lib.GrpcStringResponse;
import com.sam.lib.MyproRpcServiceGrpc;
import io.grpc.Channel;
import net.devh.boot.grpc.client.inject.GrpcClient;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;

@Service
public class DeviceGrpcService {
    @GrpcClient("person")  // grpc服务的名称
    private Channel channel;

    private MyproRpcServiceGrpc.MyproRpcServiceBlockingStub stub;

    @PostConstruct
    public void init() {
        stub = MyproRpcServiceGrpc.newBlockingStub(channel);
    }

    public String getUser(String name) {
        GrpcStringResponse response = stub.getUser(GrpcStringRequest.newBuilder().setStr(name).build());
        return response.getStr();
    }

}

步骤六：controller测试

    @GetMapping("/grpc")
    public String setGrpc() {
        String result = deviceGrpcService.getUser("device");
        if ("".equals(result)) {
            return "Result is blank";
        }
        return result;
    }

至此，grpc调用成功。