springboot——grpc实现demo

一、前言

1、应用场景：Java做为服务端给go 提供接口

 有两种方式：**http：网络传输协议**, **rpc(Remote Produce Call)远程过程调用**

两者区别: RPC 是根据语言API来定义，不是根据网络的应用定义

2、 grpc: 数据的序列化以及进程数据通信的交互方式

主要有以下几个过程

(1) 通过.proto文件定义传输的接口和消息体。

(2) 通过protocol编译器生成server端和client端的stub程序。

(3) 将请求封装成HTTP2的Stream。

(4) 通过Channel作为数据通信通道使用Socket进行数据传输。

二、springboot 构建grpc 的demo

1、版本对应：

springboot : 2.1.4.RELEASE
JDK1.8

2、项目构建

2.1 项目结构

2.2 根pom文件

    4.0.0

    
        org.springframework.boot
        spring-boot-starter-parent
        2.1.4.RELEASE
    
    com.lrbj
    grpc-springboot-demo
    0.0.1-SNAPSHOT
    grpc-springboot-demo
    Demo project for Spring Boot
    pom
    
    
        grpc-lib
        grpc-server
        grpc-client
    
    
        UTF-8
        UTF-8
        1.8
        2.1.4.RELEASE
        2.0.1.RELEASE
    
    
    

        
            com.lrbj
            grpc-lib
            ${project.version}
        
        
        
            net.devh
            grpc-client-spring-boot-starter
            ${net-devh-grpc.version}
        
        
            net.devh
            grpc-server-spring-boot-starter
            ${net-devh-grpc.version}
        

    
    

2.3 grpc-lib 模块

2.3.1 文件结构

Greeter.proto文件,关于.proto3语法

syntax = "proto3";


option java_package = "com.lrbj.grpc.lib";

// The greeting service definition.
service Greeter{
    // Sends a greeting
    rpc SayHello (HelloRequest) returns (HelloReply) {
    }
}

// The request message containing the user's name.
message HelloRequest {
    string name = 1;
}

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

2.3.2 pom文件

    4.0.0

    
        org.springframework.boot
        spring-boot-starter-parent
        2.1.4.RELEASE
    
    com.lrbj
    grpc-springboot-demo
    0.0.1-SNAPSHOT
    grpc-springboot-demo
    Demo project for Spring Boot
    pom
    
    
        grpc-lib
        grpc-server
        grpc-client
    
    
        UTF-8
        UTF-8
        1.8
        2.1.4.RELEASE
        2.0.1.RELEASE
    
    
    

        
            com.lrbj
            grpc-lib
            ${project.version}
        
        
        
            net.devh
            grpc-client-spring-boot-starter
            ${net-devh-grpc.version}
        
        
            net.devh
            grpc-server-spring-boot-starter
            ${net-devh-grpc.version}
        

    
    

根据pom文件配置在src/main/java目录下生成指定文件

2.4 grpc-server 模块

2.4.1 对应的pom 文件

    4.0.0
    
        com.lrbj
        grpc-springboot-demo
        0.0.1-SNAPSHOT
    

    grpc-server
    grpc-server
    jar
    Demo project for Spring Boot


    
        
            org.springframework.boot
            spring-boot-starter
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        
            org.projectlombok
            lombok
        

        
            com.lrbj
            grpc-lib
        
        
            net.devh
            grpc-server-spring-boot-starter
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

2.4.2 对应的application.yml

grpc.sever.address 默认值为"0.0.0.0"

spring:
  application:
    name: local-grpc-server
grpc:
  server:
    port: 8002

2.4.3 service端接口

@Slf4j
@GrpcService(GreeterOuterClass.class)
public class GreeterService extends GreeterGrpc.GreeterImplBase {
    @Override
    public void sayHello(GreeterOuterClass.HelloRequest request, StreamObserver responseObserver) {
        String message = "Hello " + request.getName();
        final GreeterOuterClass.HelloReply.Builder replyBuilder = GreeterOuterClass.HelloReply.newBuilder().setMessage(message);
        responseObserver.onNext(replyBuilder.build());
        responseObserver.onCompleted();
        log.info("Returning " + message);
    }
}

2.5 grpc-client 模块

2.5.1 对应的pom文件

    4.0.0
    
        com.lrbj
        grpc-springboot-demo
        0.0.1-SNAPSHOT
    

    grpc-client
    grpc-client
    jar
    Demo project for Spring Boot

    
        
            org.springframework.boot
            spring-boot-starter
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            com.lrbj
            grpc-lib
        
        
            net.devh
            grpc-client-spring-boot-starter
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.projectlombok
            lombok
        

    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

2.5.2 对应的application.yml

server:
  port: 8003
spring:
  application:
    name: local-grpc-client
grpc:
  client:
    local-grpc-server:
      port: 8002
      enableKeepAlive: true
      keepAliveWithoutCalls: true

2.5.3 客户端调用接口

@Service
public class GrpcClientService {

    //两种获取Channel方式
    //方法一
    @GrpcClient("local-grpc-server")
    private Channel serverChannel;

    public String sendMessage(String name) {
        GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverChannel);
        GreeterOuterClass.HelloReply response = stub.sayHello(GreeterOuterClass.HelloRequest.newBuilder().setName(name).build());
        return response.getMessage();
    }

2.5.4 测试

@RestController
public class GrpcClientController {

    @Autowired
    private GrpcClientService grpcClientService;

    @RequestMapping("/")
    public String printMessage(@RequestParam(defaultValue = "Susan") String name) {
        return grpcClientService.sendMessage(name);
    }

启动server 端然后再启动服务端
效果如下

例子源码地址：gitdemo
参考链接：
https://grpc.io/docs/quickstart/java/
https://www.cnblogs.com/tianzhiyi/p/6120909.html
https://blog.csdn.net/alinyua/article/details/83030149
http://jia-shun.cn/2018/08/12/gRPC/