java版gRPC实战之一(用proto生成代码)

愿君学长松,慎勿作桃李。这篇文章主要讲述java版gRPC实战之一:用proto生成代码相关的知识,希望能为你提供帮助。
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明确依赖库和开发环境
整个系列文章涉及的依赖库和开发环境的情况如下:

  1. JDK:1.8.0_281
  2. gradle:6.7.1
  3. springboot:2.3.8.RELEASE
  4. grpc:1.35.0
  5. protobuf:3.14.0
  6. grpc-server-spring-boot-starter:2.11.0.RELEASE
  7. grpc-client-spring-boot-starter:2.11.0.RELEASE
  8. 操作系统:win10专业版
  9. IDEA:2021.1 (Ultimate Edition)
源码下载
  • 本篇实战中的完整源码可在GitHub下载到,地址和链接信息如下表所示(https://github.com/zq2599/blog_demos):
名称 链接 备注
项目主页 https://github.com/zq2599/blog_demos 该项目在GitHub上的主页
git仓库地址(https) https://github.com/zq2599/blog_demos.git 该项目源码的仓库地址,https协议
git仓库地址(ssh) git@github.com:zq2599/blog_demos.git 该项目源码的仓库地址,ssh协议
  • 这个git项目中有多个文件夹,《java版gRPC实战》系列的源码在==grpc-tutorials==文件夹下,如下图红框所示:
    java版gRPC实战之一(用proto生成代码)

    文章图片
创建《java版gRPC实战》系列的父工程
  • 新建名为==grpc-tutorials==的gradle工程,前面提到的库及其版本都在此工程中处理好,build.gradle内容如下:
    import java.time.OffsetDateTime import java.time.format.DateTimeFormatter

buildscript
repositories
maven
url https://plugins.gradle.org/m2/

// 如果有私服就在此配置,如果没有请注释掉
maven
url http://192.168.50.43:8081/repository/aliyun-proxy/

// 阿里云
maven
url http://maven.aliyun.com/nexus/content/groups/public/

mavenCentral()ext // 项目版本 projectVersion = 1.0-SNAPSHOT// 依赖库的版本 grpcSpringBootStarterVersion = 2.11.0.RELEASE// grpc版本 https://github.com/grpc/grpc-java/releases grpcVersion = 1.35.0 // protobuf版本 https://github.com/protocolbuffers/protobuf/releases protobufVersion = 3.14.0 // protobuf的gradle插件版本 protobufGradlePluginVersion = 0.8.12// sprignboot版本 https://github.com/spring-projects/spring-boot/releases springBootVersion = 2.3.8.RELEASE // springcloud版本 https://github.com/spring-cloud/spring-cloud-release/releases springCloudVersion = Hoxton.SR9 // nacos版本 https://github.com/alibaba/spring-cloud-alibaba/releases springCloudAlibabaNacosVersion = 2.2.3.RELEASE // security版本 https://github.com/spring-projects/spring-security-oauth/releases springSecurityOAuthVersion = 2.5.0.RELEASE


plugins
id java
id java-library
id org.springframework.boot version " $springBootVersion" apply false
id io.spring.dependency-management version 1.0.11.RELEASE
id net.nemerosa.versioning version 2.14.0
id com.google.protobuf version 0.8.14
id io.franzbecker.gradle-lombok version 4.0.0 apply false
id com.github.ben-manes.versions version 0.36.0 // gradle dependencyUpdates

// If you attempt to build without the --scan parameter in gradle 6.0+ it will cause a build error that it cant find
// a buildScan property to change. This avoids that problem.
if (hasProperty(buildScan))
buildScan
termsOfServiceUrl = https://gradle.com/terms-of-service
termsOfServiceAgree = yes


wrapper
gradleVersion = 6.7.1

def buildTimeAndDate = OffsetDateTime.now()
ext
// 构建时取得当前日期和时间
buildDate = DateTimeFormatter.ISO_LOCAL_DATE.format(buildTimeAndDate)
buildTime = DateTimeFormatter.ofPattern(HH:mm:ss.SSSZ).format(buildTimeAndDate)
buildRevision = versioning.info.commit

allprojects
apply plugin: java
apply plugin: idea
apply plugin: eclipse
apply plugin: io.spring.dependency-management
apply plugin: io.franzbecker.gradle-lombok
compileJava sourceCompatibility = JavaVersion.VERSION_1_8 targetCompatibility = JavaVersion.VERSION_1_8 options.encoding = UTF-8compileJava.options*.compilerArgs = [ -Xlint:all, -Xlint:-processing ]// Copy LICENSE tasks.withType(Jar) from(project.rootDir) include LICENSE into META-INF// 写入到MANIFEST.MF中的内容 jar manifest attributes( Created-By: "$System.properties[java.version] ($System.properties[java.vendor] $System.properties[java.vm.version])".toString(), Built-By: travis, Build-Date: buildDate, Build-Time: buildTime, Built-OS: "$System.properties[os.name]", Build-Revision: buildRevision, Specification-Title: project.name, Specification-Version: projectVersion, Specification-Vendor: Will Zhao, Implementation-Title: project.name, Implementation-Version: projectVersion, Implementation-Vendor: Will Zhao )repositories mavenCentral()// 如果有私服就在此配置,如果没有请注释掉 maven url http://192.168.50.43:8081/repository/aliyun-proxy/// 阿里云 maven url http://maven.aliyun.com/nexus/content/groups/public/jcenter()buildscript repositories mavenurl https://plugins.gradle.org/m2/


allprojectsproject ->
buildscript
dependencyManagement
imports
mavenBom " org.springframework.boot:spring-boot-starter-parent:$springBootVersion"
mavenBom " org.springframework.cloud:spring-cloud-dependencies:$springCloudVersion"
mavenBom " com.google.protobuf:protobuf-bom:$protobufVersion"
mavenBom " io.grpc:grpc-bom:$grpcVersion"
mavenBom " org.junit:junit-bom:5.7.0"

dependencies dependency org.projectlombok:lombok:1.16.16 dependency org.apache.commons:commons-lang3:3.11 dependency commons-collections:commons-collections:3.2.2 dependency "net.devh:grpc-server-spring-boot-starter:$grpcSpringBootStarterVersion" dependency "net.devh:grpc-client-spring-boot-starter:$grpcSpringBootStarterVersion"ext micrometerVersion = dependencyManagement.importedProperties[micrometer.version] springFrameworkVersion = dependencyManagement.importedProperties[spring-framework.version] springSecurityVersion = dependencyManagement.importedProperties[spring-security.version] springCloudCommonsVersion = dependencyManagement.importedProperties[spring-cloud-commons.version]


group = com.bolingcavalry
version = projectVersion
- 整个系列用到的父工程已经完成,接下来可以开始编码了; ### 实战用proto文件自动生成java代码 - gRPC服务能够用不同的语言编写,其中的关键是定义服务的proto文件可以被生成各种语言的代码,java也不例外,接下来一起体验; - 在父工程==grpc-tutorials==下新建模块,名为==grpc-lib==,其build.gradle内容如下,可见主要是配置了protobuf插件,以及生成的java代码如何才能被IDE工具加入到source path中: ```groovy // 根据proto生成java代码的gradle插件 plugins id com.google.protobufdependencies implementation io.grpc:grpc-netty-shaded implementation io.grpc:grpc-protobuf implementation io.grpc:grpc-stub if (JavaVersion.current().isJava9Compatible()) // Workaround for @javax.annotation.Generated // see: https://github.com/grpc/grpc-java/issues/3633 implementation jakarta.annotation:jakarta.annotation-apiprotobuf protoc artifact = "com.google.protobuf:protoc:$protobufVersion"// 自动生成的代码放在这里 generatedFilesBaseDir = "$projectDir/src/generated" clean delete generatedFilesBaseDir// 生成java代码的插件 plugins grpc artifact = io.grpc:protoc-gen-grpc-javagenerateProtoTasks all()*.plugins grpc // 对于eclipse,通过以下脚本可以将生成的代码加入source路径中,编译时会被用到 eclipse classpath file.beforeMergedcp -> def generatedGrpcFolder = new org.gradle.plugins.ide.eclipse.model.SourceFolder(src/generated/main/grpc, null); generatedGrpcFolder.entryAttributes[ignore_optional_problems] = true; cp.entries.add( generatedGrpcFolder ); def generatedJavaFolder = new org.gradle.plugins.ide.eclipse.model.SourceFolder(src/generated/main/java, null); generatedJavaFolder.entryAttributes[ignore_optional_problems] = true; cp.entries.add( generatedJavaFolder ); // 对于idea,通过以下脚本可以将生成的代码加入source路径中,编译时会被用到 idea module sourceDirs += file(src/generated/main/java) sourceDirs += file(src/generated/main/grpc) generatedSourceDirs += file(src/generated/main/java) generatedSourceDirs += file(src/generated/main/grpc)

  • 在grpc-lib模块的==src/main/proto==目录下新增名为==helloworld.proto==的文件,这里面定义了一个gRPC服务,里面含有一个接口,并且还有这个接口的入参和返回结果的定义:
    syntax = "proto3";

【java版gRPC实战之一(用proto生成代码)】option java_multiple_files = true;
// 生成java代码的package
option java_package = " com.bolingcavalry.grpctutorials.lib" ;
option java_outer_classname = " HelloWorldProto" ;
// gRPC服务
service Simple
// 接口定义
rpc SayHello (HelloRequest) returns (HelloReply)


// 入参的数据结构
message HelloRequest
string name = 1;

// 返回结果的数据结构
message HelloReply
string message = 1;

- proto文件已经做好,接下来要根据这个文件来生成java代码,在==grpc-tutorials==目录下执行命令==gradle grpc-lib:generateProto==,即可根据helloworld.proto文件生成java代码,执行成功后会生出下图红框中的内容,这些就是java代码: ![在这里插入图片描述](https://s4.51cto.com/images/blog/202112/23081042_61c3be826207538379.png?x-oss-process=image/watermark,size_14,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=) - 本篇只聊如何生成上述代码,至于这些代码的用途就留到下一篇再说吧,这里只简单提一下,SimpleGrpc里面有抽象类SimpleImplBase,制作gRPC服务的时候需要继承该类,另外,如果您要远程调用gRPC的sayHello接口,就会用到SimpleGrpc类中的SimpleStub类,其余的HelloReply、HelloRequest这些则是入参和返回的数据结构定义; - 至此,java版gRPC实战的准备工作就完成了,根据proto文件生成java代码的方法也掌握了,接下来的章节咱们一起尝试服务的发布和调用;### 欢迎关注公众号:程序员欣宸 > 微信搜索「程序员欣宸」,我是欣宸,期待与您一同畅游Java世界...


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