Replace all transferTo to Kotlinx transfer, downgrade JDK requirement

mirai-core/src/commonMain/kotlin/net.mamoe.mirai/utils/io/InputUtils.kt

@@ -2,6 +2,8 @@
 
 package net.mamoe.mirai.utils.io
 
+import kotlinx.io.InputStream
+import kotlinx.io.OutputStream
 import kotlinx.io.core.*
 import kotlinx.io.pool.useInstance
 import kotlin.jvm.JvmName

mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/network/BotSessionJvm.kt

@@ -1,8 +1,12 @@
 package net.mamoe.mirai.network
 
+import io.ktor.util.KtorExperimentalAPI
 import kotlinx.coroutines.Dispatchers.IO
 import kotlinx.coroutines.withContext
+import kotlinx.io.core.copyTo
 import kotlinx.io.core.use
+import kotlinx.io.streams.asInput
+import kotlinx.io.streams.asOutput
 import kotlinx.io.streams.inputStream
 import net.mamoe.mirai.Bot
 import net.mamoe.mirai.message.Image
@@ -31,5 +35,11 @@ actual class BotSession internal actual constructor(
     suspend inline fun Image.downloadAsExternalImage(): ExternalImage = download().use { it.toExternalImage() }
 
     suspend inline fun Image.downloadTo(file: File) = file.outputStream().use { downloadTo(it) }
-    suspend inline fun Image.downloadTo(output: OutputStream) = download().inputStream().use { input -> withContext(IO) { input.transferTo(output) } }
+
+    /**
+     * 需要调用者自行 close [output]
+     */
+    @UseExperimental(KtorExperimentalAPI::class)
+    suspend inline fun Image.downloadTo(output: OutputStream) =
+        download().inputStream().asInput().use { input -> withContext(IO) { input.copyTo(output.asOutput()) } }
 }

mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/utils/ExternalImageJvm.kt

@@ -4,12 +4,15 @@ package net.mamoe.mirai.utils
 
 import io.ktor.util.asStream
 import kotlinx.coroutines.Dispatchers.IO
+import kotlinx.coroutines.io.jvm.javaio.copyTo
 import kotlinx.coroutines.withContext
 import kotlinx.io.core.Input
 import kotlinx.io.core.IoBuffer
 import kotlinx.io.core.buildPacket
+import kotlinx.io.core.copyTo
 import kotlinx.io.errors.IOException
 import kotlinx.io.streams.asInput
+import kotlinx.io.streams.asOutput
 import java.awt.image.BufferedImage
 import java.io.File
 import java.io.InputStream
@@ -81,9 +84,9 @@ suspend fun File.suspendToExternalImage(): ExternalImage = withContext(IO) { toE
 @Throws(IOException::class)
 fun URL.toExternalImage(): ExternalImage {
     val file = createTempFile().apply { deleteOnExit() }
-    file.outputStream().use { output ->
+    file.outputStream().asOutput().use { output ->
-        openStream().use { input ->
+        openStream().asInput().use { input ->
-            input.transferTo(output)
+            input.copyTo(output)
         }
     }
     return file.toExternalImage()
@@ -101,8 +104,8 @@ suspend fun URL.suspendToExternalImage(): ExternalImage = withContext(IO) { toEx
 @Throws(IOException::class)
 fun InputStream.toExternalImage(): ExternalImage {
     val file = createTempFile().apply { deleteOnExit() }
-    file.outputStream().use {
+    file.outputStream().asOutput().use {
-        this.transferTo(it)
+        this.asInput().copyTo(it)
     }
     this.close()
     return file.toExternalImage()
@@ -120,8 +123,8 @@ suspend fun InputStream.suspendToExternalImage(): ExternalImage = withContext(IO
 @Throws(IOException::class)
 fun Input.toExternalImage(): ExternalImage {
     val file = createTempFile().apply { deleteOnExit() }
-    file.outputStream().use {
+    file.outputStream().asOutput().use {
-        this.asStream().transferTo(it)
+        this.asStream().asInput().copyTo(it)
     }
     return file.toExternalImage()
 }

mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/utils/PlatformUtilsJvm.kt

@@ -4,6 +4,10 @@ package net.mamoe.mirai.utils
 
 import io.ktor.client.HttpClient
 import io.ktor.client.engine.cio.CIO
+import kotlinx.io.core.Output
+import kotlinx.io.core.copyTo
+import kotlinx.io.streams.asInput
+import kotlinx.io.streams.asOutput
 import java.io.DataInput
 import java.io.EOFException
 import java.io.InputStream
@@ -21,13 +25,13 @@ actual fun md5(byteArray: ByteArray): ByteArray = MessageDigest.getInstance("MD5
 fun InputStream.md5(): ByteArray {
     val digest = MessageDigest.getInstance("md5")
     digest.reset()
-    this.transferTo(object : OutputStream() {
+    this.asInput().copyTo(object : OutputStream() {
         override fun write(b: Int) {
             b.toByte().let {
                 digest.update(it)
             }
         }
-    })
+    }.asOutput())
     return digest.digest()
 }