Protobuf + gRPC Android Studio接入指南

  一.添加protobuf-gradle-plugin插件

1.项目根目录build.gradle里添加:

buildscript {
  repositories {
    mavenCentral()
  }
  dependencies {
    classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.6'
  }
}

2.Module下build.gradle里添加:

Android插件必须在Protobuf插件之前:

apply plugin: 'com.android.application'  // or 'com.android.library'
apply plugin: 'com.google.protobuf'

设置proto文件位置(src/main/proto):

android {
  sourceSets {
    main {
      proto {
        srcDir 'src/main/proto'
        ...
      }
    }
  }
}   

自定义Protobuf编译项:

android {
    protobuf {
        // Configure the protoc executable
        protoc {
            // Download from repositories
            artifact = 'com.google.protobuf:protoc:3.6.1' // 这里可以手工指定 path = '/usr/local/bin/protoc'
        }
        plugins {
            // Optional: an artifact spec for a protoc plugin, with "grpc" as
            // the identifier, which can be referred to in the "plugins"
            // container of the "generateProtoTasks" closure.
            javalite {
                artifact = "com.google.protobuf:protoc-gen-javalite:3.0.0"
            }
        }
        generateProtoTasks {
            all()*.plugins {
                javalite {}

            }
        }
    }

}

加入依赖包:

dependencies {
  // You need to depend on the lite runtime library, not protobuf-java
  api 'com.google.protobuf:protobuf-lite:3.0.1'
  api "javax.annotation:javax.annotation-api:1.2"  //这个依赖是解决注释报错的问题

}

同步.rebuild 至此build/generated/source/proto/目录下生成相对应的XxxOuterClass文件

引用:

1)https://github.com/google/protobuf-gradle-plugin

2)https://search.maven.org/search?q=g:com.google.protobuf

3)https://blog.csdn.net/YongYu_IT/article/details/80430318

注:

引用1)中有句话Android projects: no default output will be added. Since Protobuf 3.0.0, protobuf-lite is the recommended Protobuf library for Android, and you will need to add it as a codegen plugin.大概意思是Android的项目是没有默认的输出类型这个不同于GO,PHP,PYTHON的项目,从Protobuf 3.0.0后,在Android项目中推荐使用protobuf-lite为做为引用库.这一点尤为重要,不然在后面grpc的生成时很容易出错,该库对应的版本号通过引用2)进行查看

二.grpc代码生成

1.在protobuf选项增加相应代码

android {
    protobuf {
        // Configure the protoc executable
        protoc {
            // Download from repositories
            artifact = 'com.google.protobuf:protoc:3.6.1'
        }
        plugins {
            // Optional: an artifact spec for a protoc plugin, with "grpc" as
            // the identifier, which can be referred to in the "plugins"
            // container of the "generateProtoTasks" closure.
            javalite {
                artifact = "com.google.protobuf:protoc-gen-javalite:3.0.0"
            }
            grpc {
                artifact = "io.grpc:protoc-gen-grpc-java:1.14.0"
            }
        }
        generateProtoTasks {
            all()*.plugins {
                javalite {}
                grpc {
                    option 'lite'
                }
            }
        }
    }

}

2.加入依赖包:

api 'io.grpc:grpc-okhttp:1.14.0'
api 'io.grpc:grpc-protobuf-lite:1.14.0'
api'io.grpc:grpc-stub:1.14.0'

引用:

1)https://github.com/grpc/grpc-java