Android加快Gradle编译速度（Kotlin）

做以下几点配置：

1. 在项目根目录下新建gradle.properties文件(没有的话)，修改内容如下：

# Project-wide Gradle settings.
# IDE (e.g. Android Studio) users:
# Gradle settings configured through the IDE *will override*
# any settings specified in this file.
# For more details on how to configure your build environment visit
# http://www.gradle.org/docs/current/userguide/build_environment.html
# Specifies the JVM arguments used for the daemon process.
# The setting is particularly useful for tweaking memory settings.
# org.gradle.jvmargs=-Xmx1536m
# 开启gradle并行编译，开启daemon，调整jvm内存大小
org.gradle.daemon=true
org.gradle.configureondemand=true
org.gradle.parallel=true
org.gradle.jvmargs=-Xmx4096m -XX:MaxPermSize=1024m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
# When configured, Gradle will run in incubating parallel mode.
# This option should only be used with decoupled projects. More details, visit
# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
# org.gradle.parallel=true
# AndroidX package structure to make it clearer which packages are bundled with the
# Android operating system, and which are packaged with your app's APK
# https://developer.android.com/topic/libraries/support-library/androidx-rn
android.useAndroidX=true
# Automatically convert third-party libraries to use AndroidX
android.enableJetifier=true
# Kotlin code style for this project: "official" or "obsolete":
kotlin.code.style=official
# 开启gradle缓存
org.gradle.caching=true
android.enableBuildCache=true
# 开启kotlin的增量和并行编译
kotlin.incremental=true
kotlin.incremental.java=true
kotlin.incremental.js=true
kotlin.caching.enabled=true
# 开启kotlin并行编译
kotlin.parallel.tasks.in.project=true
# 优化kapt
# 并行运行kapt1.2.60版本以上支持
kapt.use.worker.api=true
# 增量编译 kapt1.3.30版本以上支持
kapt.incremental.apt=true
# kapt avoiding 如果用kapt依赖的内容没有变化，会完全重用编译内容，省掉`app:kaptGenerateStubsDebugKotlin`的时间
kapt.include.compile.classpath=false

最后在app级别下的build.gradle下添加如下内容：

在android闭包下添加：

android {

    // 优化编译速度
    // 优化`transformClassDexBuilderForDebug`的速度
    dexOptions {
        preDexLibraries true
        maxProcessCount 8
    }

    // 优化版本控制 release版本使用动态版本号 debug版本使用固定版本号
    // 影响不大 Cannot set the value of read-only property 'versionName' for object of ... ?
//    applicationVariants.all { variant ->
//        if (variant.buildType.name == "release") {
//            versionName = currentName()
//            versionCode = currentCode()
//        }
//    }
...
}

添加kapt闭包

// 优化编译速度 如果有用到kapt添加如下配置
kapt {
    useBuildCache = true
    javacOptions {
        option("-Xmaxerrs", 500)
    }
}

至此便完成了Kotlin下Gradle的编译速度的优化。