如何在buildSrc/build.gradle.kts，settings.gradle.kts 和build.gra

Question

我想创建一个类来帮助我加载不同类型的属性(local.properties、gradle.properties、$GRADLE_HOME/gradle.properties、环境变量、系统属性和自定义属性文件(可能采用其他格式，如yml、xml等(。

另外，我想在我的buildSrc/build.gradle.kts、settings.gradle.kts和build.gradle.kts中使用它。

请注意，我们正在使用Gradle 6.+。

这个类的简单实现将是(完整的实现会更强大(：

plugins/properties/build.gradle.kts：

package com.example
object Properties {
val environmentVariables = System.getenv()
}

我们如何才能成功地将这个Properties类导入到所有这些文件(buildSrc/build.gradle.kts、settings.gradle.kts、build.gradle.kts(中并从那里使用它？像这样：

println(com.example.Properties.environmentVariables["my.property"](

我们可以在插件中创建此类并从那里应用它吗？没有预编译和发布插件？也许像这样：

apply("plugins/properties/build.gradle.kts"(

它将如何成为此的最小实现？

我尝试了不同的方法，但我无法找到完全处理这 3 个文件的方法。

Answer 1

我对这种方法并不完全满意，但也许它可以帮助其他人。 我无法在所有地方重用一个类，而是一个函数，如下所示：

settings.gradle.kts

apply("plugin/properties/build.gradle.kts")
@Suppress("unchecked_cast", "nothing_to_inline")
inline fun <T> uncheckedCast(target: Any?): T = target as T
val getProperty = uncheckedCast<(key: String) -> String>(extra["getProperty"])
println(getProperty("group"))

buildSrc/build.gradle.kts

apply("../plugin/properties/build.gradle.kts")
@Suppress("unchecked_cast", "nothing_to_inline")
inline fun <T> uncheckedCast(target: Any?): T = target as T
val getProperty = uncheckedCast<(key: String) -> String>(extra["getProperty"])
println(getProperty("group"))

build.gradle.kts

// Can be used inside of the file
apply("plugin/properties/build.gradle.kts")
@Suppress("unchecked_cast", "nothing_to_inline")
inline fun <T> uncheckedCast(target: Any?): T = target as T
val getProperty = uncheckedCast<(key: String) -> String>(extra["getProperty"])
println(getProperty("group"))
buildScript {
// Since the other getProperty is not visible here we need to do this again.
apply("plugin/properties/build.gradle.kts")
@Suppress("unchecked_cast", "nothing_to_inline")
inline fun <T> uncheckedCast(target: Any?): T = target as T
val getProperty = uncheckedCast<(key: String) -> String>(extra["getProperty"])
println(getProperty("group"))
}

plugin/properties/build.gradle.kts

import java.io.File
import java.nio.file.Path
import java.nio.file.Paths
import java.util.Properties as JavaProperties
import org.gradle.api.initialization.ProjectDescriptor
object Properties {
lateinit var rootProjectAbsolutePath : String
val local: JavaProperties by lazy {
loadProperties(JavaProperties(), Paths.get(rootProjectAbsolutePath, "local.properties").toFile())
}
val environment by lazy {
System.getenv()
}
val system: JavaProperties = JavaProperties()
val gradle: JavaProperties by lazy {
loadProperties(JavaProperties(), Paths.get(rootProjectAbsolutePath, "gradle.properties").toFile())
}
val globalGradle: JavaProperties by lazy {
loadProperties(JavaProperties(), Paths.get(System.getProperty("user.home"), ".gradle", "gradle.properties").toFile())
}
fun containsKey(vararg keys: String): Boolean {
if (keys.isNullOrEmpty()) return false
keys.forEach {
when {
local.containsKey(it) -> return true
environment.containsKey(it) -> return true
system.containsKey(it) -> return true
gradle.containsKey(it) -> return true
globalGradle.containsKey(it) -> return true
}
}
return false
}
fun get(vararg keys: String): String {
return this.getAndCast<String>(*keys) ?: throw IllegalArgumentException("Property key(s) ${keys} not found.")
}
fun getOrNull(vararg keys: String): String? {
return getAndCast<String>(*keys)
}
inline fun <reified R> getOrDefault(vararg keys: String, default: R?): R? {
return getAndCast<R>(*keys) ?: default
}
inline fun <reified R> getAndCast(vararg keys: String): R? {
if (keys.isNullOrEmpty()) return null
keys.forEach {
val value = when {
local.containsKey(it) -> local[it]
environment.containsKey(it) -> environment[it]
system.containsKey(it) -> system[it]
gradle.containsKey(it) -> gradle[it]
globalGradle.containsKey(it) -> globalGradle[it]
else -> null
}
// TODO Improve the casting using Jackson
if (value != null) return value as R
}
return null
}
private fun loadProperties(target: JavaProperties, file: File): JavaProperties {
if (file.canRead()) {
file.inputStream().use { target.load(it) }
}
return target
}
}
if (rootProject.name == "buildSrc") {
Properties.rootProjectAbsolutePath = rootDir.parent
} else {
Properties.rootProjectAbsolutePath = rootDir.absolutePath
}
extra["getProperty"] = {key: String -> Properties.get(key)}