当涉及到多module组合开发时，每个module的build.gradle文件都拥有一些必要的属性，同一个Android工程中，在不同模块中要求这些属性一致，例如complieSdkVersion、buildToolVersion等。如果引用不一致，属性就不会合并到工程中，这样一方面会造成资源的重复，使得最终生成的APK包量增大，另一方面也会降低编译的效率。

那么就必须有一个统一的、基础的Gradle配置，通过编写一个common_config.gradle（文件名可自定义），在各module的build.gradle，通过apply引用，然后达到一致性的作用，下面给出一个简易的示例，包含了定义一些共用变量、函数或者带参方法，而且支持android application、android library和java library模块配置。

import java.text.SimpleDateFormatproject.ext {versions = ["compileSdkVersion": 28,"buildToolsVersion": "28.0.3","minSdkVersion"    : 21,"targetSdkVersion" : 28,"versionCode"      : 1,"versionName"      : "1.0.0"]dependencieLibs = [// 依赖包"appcompat-v7"       : 'androidx.appcompat:appcompat:1.0.0',"constraint-layout"  : 'androidx.constraintlayout:constraintlayout:1.1.3',//kotlin"kotlin-stdlib-jdk7": "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version","kotlin-reflect"    : "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version","junit"             : "junit:junit:4.13",]buildTime = {def df = new SimpleDateFormat("yyyyMMddHHmm")df.setTimeZone(TimeZone.getDefault())return df.format(new Date())}/*** android app config*/setAppDefaultConfig = {extension ->extension.apply plugin: 'com.android.application'extension.apply plugin: 'kotlin-android'extension.description "app"setAndroidConfig extension.androidsetDependencies extension.dependencies}/*** android library config*/setLibDefaultConfig = {extension ->extension.apply plugin: 'com.android.library'extension.apply plugin: 'kotlin-android'extension.description "lib"setAndroidConfig extension.androidsetDependencies extension.dependencies}/*** java library config*/setJavaLibDefaultConfig = {extension ->extension.apply plugin: 'java-library'extension.apply plugin: 'kotlin'extension.description "javalib"setDependencies extension.dependenciesextension.sourceCompatibility = "1.8"extension.targetCompatibility = "1.8"}/*** android project android {} default config*/setAndroidConfig = {extension ->extension.compileSdkVersion versions['compileSdkVersion']extension.buildToolsVersion versions['buildToolsVersion']extension.defaultConfig {minSdkVersion versions['minSdkVersion']targetSdkVersion versions['targetSdkVersion']versionCode versions['versionCode']versionName versions['versionName']testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"}extension.compileOptions {targetCompatibility = '1.8'sourceCompatibility = '1.8'}extension.kotlinOptions {jvmTarget = "1.8"}}/*** android project dependencies {} default config*/setDependencies = {extension ->extension.implementation fileTree(include: ['*.jar'], dir: 'libs')extension.implementation dependencieLibs['kotlin-stdlib-jdk7']extension.testImplementation dependencieLibs['junit']}//get git version sha fungetGitSha = {project ->try {String gitRev = 'git rev-parse --short HEAD'.execute(null, project.rootDir).text.trim()if (gitRev == null) {throw new GradleException("can't get git rev, you should add git to system path or just input test value, such as 'testTinkerId'")}return gitRev} catch (Exception e) {throw new GradleException("can't get git rev, you should add git toCon system path or just input test value, such as 'testTinkerId'")}}
}