【20200127】SpringBoot Grpc

一.背景

Spring Boot是由Pivotal团队提供的全新框架，其设计目的是用来简化新Spring应用的初始搭建以及开发过程。该框架使用了特定的方式来进行配置，从而使开发人员不再需要定义样板化的配置。通过这种方式，Spring Boot致力于在蓬勃发展的快速应用开发领域(rapid application development)成为领导者。
Grpc 由 google 开发，是一款语言中立、平台中立、开源的远程过程调用(RPC)系统。
项目定位是电商平台和WMS系统中间的插件服务，wms采用.net语言开发，电商平台采用java开发，所以出现了多语言间的数据交换，开始考虑使用json协议，方便快捷，但是考虑到效率和系统发展的问题，考虑使用RPC框架，斟酌之后敲定为GRPC。
但是，我们拓展服务使用的SpringBoot，Grpc和SpringBoot集成的文章不是很多，大部分都是采用github上*-springboot.grpc.starter的项目，看了一下，并不是很感兴趣，所以自己根据官网的demo，尝试与SpringBoot集成，所以在这和大家分享下

二. 准备工作

开发环境

Spring Boot 2.0.5.RELEASE Grpc 1.15.0 Inteliji Idea 2018.3

项目截图

三.实现过程

1. 配置SpringBoot项目

• Pom文件增加

  <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
    </dependencies>

• 编写启动类

  public static void main(String[] args) {
    // 启动SpringBoot web
    SpringApplication.run(Launcher.class, args);
  }

  2. 增加GRPC支持和GRPC代码生成工具，集成GrpcServer端

• 增加POM文件

  <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-netty-shaded</artifactId>
            <version>1.15.0</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-protobuf</artifactId>
            <version>1.15.0</version>
        </dependency>
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-stub</artifactId>
            <version>1.15.0</version>
        </dependency>

• 增加maven工具

  <build>
        <extensions>
            <extension>
                <groupId>kr.motd.maven</groupId>
                <artifactId>os-maven-plugin</artifactId>
                <version>1.5.0.Final</version>
            </extension>
        </extensions>
        <plugins>
            <plugin>
                <groupId>org.xolstice.maven.plugins</groupId>
                <artifactId>protobuf-maven-plugin</artifactId>
                <version>0.5.1</version>
                <configuration>
                    <protocArtifact>com.google.protobuf:protoc:3.5.1-1:exe:${os.detected.classifier}</protocArtifact>
                    <pluginId>grpc-java</pluginId>
                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.15.0:exe:${os.detected.classifier}</pluginArtifact>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>compile-custom</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

• 编写Server端实现类

  public class HelloWorldService extends HelloWorldServiceGrpc.HelloWorldServiceImplBase {
    @Override
    public void welcome(HelloWorld.NameRequest request, StreamObserver<HelloWorld.EchoResponse> responseObserver) {
        HelloWorld.EchoResponseOrBuilder echoResponseOrBuilder = HelloWorld.EchoResponse.newBuilder();
        ((HelloWorld.EchoResponse.Builder) echoResponseOrBuilder).setMergename("welcome " + request.getName());
        responseObserver.onNext(((HelloWorld.EchoResponse.Builder) echoResponseOrBuilder).build());
        responseObserver.onCompleted();
    }
  }

• 增加Grpc启动器

  @Component("grpcLauncher")
  public class GrpcLauncher {
    private Logger logger = LoggerFactory.getLogger(Launcher.class);
    /**
     * 定义Grpc Server
     */
    private Server server;
    @Value("${grpc.server.port}")
    private Integer grpcServerPort;
    /**
     * GRPC 服务启动方法
     * @param grpcServiceBeanMap
     */
    public void grpcStart(Map<String, Object> grpcServiceBeanMap) {
        try{
            ServerBuilder serverBuilder = ServerBuilder.forPort(grpcServerPort);
            for (Object bean : grpcServiceBeanMap.values()){
                serverBuilder.addService((BindableService) bean);
                logger.info(bean.getClass().getSimpleName() + " is regist in Spring Boot");
            }
            server = serverBuilder.build().start();
            logger.info("grpc server is started at " +  grpcServerPort);
            server.awaitTermination();
            Runtime.getRuntime().addShutdownHook(new Thread(()->{grpcStop();}));
        } catch (IOException e){
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
    /**
     * GRPC 服务Stop方法
     */
    private void grpcStop(){
        if (server != null){
            server.shutdownNow();
        }
    }
  }

• 添加自定义注解用于扫描Grpc服务

  /**
  * 自定义注解，用于获取Spring扫描到的类
  */
  @Target({ElementType.TYPE})
  @Retention(RetentionPolicy.RUNTIME)
  @Documented
  @Component
  public @interface GrpcService {
  }

• 在SpringBoot中增加Grpc启动器，并将Spring管理的类，添加到Grpc服务中

  /**
  * Spring Boot 启动器
  */
  @SpringBootApplication
  public class Launcher {
    public static void main(String[] args) {
        // 启动SpringBoot web
        ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(Launcher.class, args);
        Map<String, Object> grpcServiceBeanMap =  configurableApplicationContext.getBeansWithAnnotation(GrpcService.class);
        GrpcLauncher grpcLauncher = configurableApplicationContext.getBean("grpcLauncher",GrpcLauncher.class);
        grpcLauncher.grpcStart(grpcServiceBeanMap);
    }
  }

  至此Server端，集成完毕

3. 增加Client端

• 获取Chanel

  @Component
  public class GrpcClientMananer {
    @Value("${grpc.client.host}")
    private String host;
    @Value("${grpc.client.port}")
    private Integer port;
    public ManagedChannel getChannel(){
        ManagedChannel channel = ManagedChannelBuilder.forAddress(host,port)
                .disableRetry()
                .idleTimeout(2, TimeUnit.SECONDS)
                .build();
        return channel;
    }
  }

• 调用方式

  @Component public class HelloWorldClient {
  @Autowired
  private GrpcClientMananer grpcClientMananer;
  public void call(){
    ManagedChannel channel = grpcClientMananer.getChannel();
    HelloWorld.NameRequestOrBuilder nameRequestOrBuilder = HelloWorld.NameRequest.newBuilder();
    ((HelloWorld.NameRequest.Builder) nameRequestOrBuilder).setName("Geek");
    HelloWorldServiceGrpc.HelloWorldServiceBlockingStub stub = HelloWorldServiceGrpc.newBlockingStub(channel);
    HelloWorld.EchoResponse echoResponse = stub.welcome(((HelloWorld.NameRequest.Builder) nameRequestOrBuilder).build());
    System.out.println(echoResponse.getMergename());
  }
  }

参考资料

• https://segmentfault.com/a/1190000020272545
• 参考：https://github.com/grpc/grpc-java