如何在 gradle 中执行或构建子项目之前执行任务？

Question

How to execute a task before executing or building the subprojects in gradle?

I have a multi-project build with the following build.gradle in the root project

apply plugin: 'java'
apply plugin: 'com.google.protobuf'

protobuf {

   protoc {
    // Download from repositories
    artifact = 'com.google.protobuf:protoc:3.10.0'
   }

   plugins {
      grpc {
        artifact = 'io.grpc:protoc-gen-grpc-java:1.23.0'
      }
   }

   generateProtoTasks {
      ofSourceSet('main')*.plugins {
        grpc {}
      }
   }
}

tasks.withType(JavaCompile) {
  dependsOn 'protobuf'
}

allprojects {

}

subprojects {

}

I want the protobuf tasks to be executed first before compiling any of the subprojects because my subprojects depends on the generated java files from protobuf task. so how can I achieve this? I don't want to have the protobuf task in each subproject instead I just want to do it at once at the root project but before compiling the subprojects.

Answer 1

I have created a sample project for this. The root project is called ' protobuffer ' and it has two sub projects as follows:

• java-project
• proto

' proto ' project contains proto files for the java project. proto project's build.gradle.kts file is as follows:

import com.google.protobuf.gradle.*

plugins {
    id ("com.google.protobuf")
}

tasks.check { dependsOn("generateProto") }

protobuf {
    protoc {
        artifact = "com.google.protobuf:protoc:3.6.1"
    }

    generatedFilesBaseDir = File(project(":java-project").projectDir.toString(), "src").toString()
}

dependencies {
    implementation("com.google.protobuf:protobuf-java:3.6.1")
}

Root project's build.gradle.kts file is as follows:

import com.google.protobuf.gradle.GenerateProtoTask
plugins {
    java
    id ("com.google.protobuf") version ("0.8.8") apply false
}

allprojects {
    repositories {
        mavenCentral()
        maven {
            url = uri("https://plugins.gradle.org/m2/")
        }
    }
}

subprojects {
    apply(plugin="java")
    apply(plugin="idea")

    if (name != "proto") {
        tasks.withType<JavaCompile> {
            dependsOn(project(":proto").tasks.withType<GenerateProtoTask>())
        }
    }
}

The settings.gradle.kts file in the root project is as follows:

rootProject.name = "protobuffer"
include("proto")
include("java-project")


pluginManagement {
    repositories {
        mavenLocal()
        maven {
            url = uri("https://plugins.gradle.org/m2/")
        }
    }

    resolutionStrategy {
        eachPlugin {
            if (requested.id.id == "com.google.protobuf") {
                useModule("com.google.protobuf:protobuf-gradle-plugin:${requested.version}")
            }
        }
    }
}