Fix Android compatibility issues (#209)

* Use animalsniffer plugin to verify compatibility with Android
* Use java.io.File instead of java.nio.files.Path
* Mention Android API compatibility in README

Closes #202

Author: fzhinkin

README.md

@@ -69,6 +69,11 @@ Add the library to dependencies:
 </dependency>
 ```
 
+### Android
+
+`kotlinx-io` is not tested on Android on a regular basis,
+but the library is compatible with Android 5.0+ (API level 21+).
+
 ## Contributing
 
 Read the [Contributing Guidelines](CONTRIBUTING.md).

build-logic/build.gradle.kts

@@ -13,4 +13,5 @@ repositories {
 
 dependencies {
     implementation(libs.kotlin.gradle.plugin)
+    implementation(libs.animalsniffer.gradle.plugin)
 }

build-logic/src/main/kotlin/kotlinx/io/conventions/kotlinx-io-android-compat.gradle.kts

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE.txt file.
+ */
+
+import ru.vyarus.gradle.plugin.animalsniffer.AnimalSnifferExtension
+
+pluginManager.withPlugin("java") {
+    apply(plugin = "ru.vyarus.animalsniffer")
+
+    configure<AnimalSnifferExtension> {
+        sourceSets = listOf((project.extensions.getByName("sourceSets") as SourceSetContainer).getByName("main"))
+    }
+    val signature: Configuration by configurations
+    dependencies {
+        // Use the same API level as OkHttp
+        signature("net.sf.androidscents.signature:android-api-level-21:5.0.1_r2@signature")
+    }
+}

bytestring/build.gradle.kts

@@ -3,6 +3,7 @@ import org.jetbrains.dokka.gradle.DokkaTaskPartial
 plugins {
     id("kotlinx-io-multiplatform")
     id("kotlinx-io-publish")
+    id("kotlinx-io-android-compat")
     alias(libs.plugins.kover)
     alias(libs.plugins.dokka)
 }

core/build.gradle.kts

@@ -8,6 +8,7 @@ import org.jetbrains.dokka.gradle.DokkaTaskPartial
 plugins {
     id("kotlinx-io-multiplatform")
     id("kotlinx-io-publish")
+    id("kotlinx-io-android-compat")
     alias(libs.plugins.kover)
     alias(libs.plugins.dokka)
 }

core/jvm/src/files/Paths.kt

@@ -6,15 +6,14 @@
 package kotlinx.io.files
 
 import kotlinx.io.*
+import java.io.File
 import java.io.FileInputStream
 import java.io.FileOutputStream
-import java.nio.file.*
-import java.nio.file.Path as NioPath
 
-public actual class Path internal constructor(internal val nioPath: NioPath)
+public actual class Path internal constructor(internal val file: File)
 
-public actual fun Path(path: String): Path = Path(Paths.get(path))
+public actual fun Path(path: String): Path = Path(File(path))
 
-public actual fun Path.source(): Source = FileInputStream(nioPath.toFile()).asSource().buffered()
+public actual fun Path.source(): Source = FileInputStream(file).asSource().buffered()
 
-public actual fun Path.sink(): Sink = FileOutputStream(nioPath.toFile()).asSink().buffered()
+public actual fun Path.sink(): Sink = FileOutputStream(file).asSink().buffered()

gradle/libs.versions.toml

@@ -7,12 +7,15 @@ bcv = "0.13.2"
 benchmark = "0.4.9"
 jmh = "1.36"
 coroutines = "1.7.3"
+animalsniffer = "1.7.1"
 
 [libraries]
 
 kotlinx-benchmark-runtime = { group = "org.jetbrains.kotlinx", name = "kotlinx-benchmark-runtime", version.ref = "benchmark" }
 kotlin-gradle-plugin = { group = "org.jetbrains.kotlin", name = "kotlin-gradle-plugin", version.ref = "kotlin" }
 kotlinx-coroutines-core = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-core", version.ref = "coroutines" }
+animalsniffer-gradle-plugin = { group = "ru.vyarus", name = "gradle-animalsniffer-plugin", version.ref = "animalsniffer" }
+
 [plugins]
 
 dokka = { id = "org.jetbrains.dokka", version.ref = "dokka" }