build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.3'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
    tasks.withType(JavaCompile){
        options.encoding = "UTF-8"
        sourceCompatibility = org.gradle.api.JavaVersion.VERSION_1_8
        targetCompatibility = org.gradle.api.JavaVersion.VERSION_1_8
    }
    tasks.withType(Javadoc) {
        options.encoding = 'UTF-8'
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}
task deleteDescriptors(type: Exec) { //执行shell命令
    executable "sh"
    args "-c", "rm -rf ~/.gradle/caches/modules-2/metadata-2.16/descriptors/com.ytjojo"
    //此处的“com.company.appname“就是之前定义的“repositoryGroup“。
}

task cleanLocalAAR(type: Delete, dependsOn: deleteDescriptors) { //clean工程时顺带执行上述任务
    delete rootProject.buildDir
}