Added kotlinx.serialization serializers

src/main/kotlin/net/axay/kspigot/serialization/ConfigurationSerializableAdapter.kt

@@ -0,0 +1,50 @@
+package net.axay.kspigot.serialization
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.builtins.ByteArraySerializer
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import org.bukkit.Color
+import org.bukkit.Location
+import org.bukkit.configuration.serialization.ConfigurationSerializable
+import org.bukkit.inventory.ItemStack
+import org.bukkit.inventory.meta.ItemMeta
+import org.bukkit.util.BoundingBox
+import org.bukkit.util.Vector
+import org.bukkit.util.io.BukkitObjectInputStream
+import org.bukkit.util.io.BukkitObjectOutputStream
+import java.io.ByteArrayOutputStream
+import kotlin.reflect.KClass
+
+object ColorSerializer: KSerializerForBukkit<Color>(Color::class)
+object BoundingBoxSerializer: KSerializerForBukkit<BoundingBox>(BoundingBox::class)
+object ItemMetaSerializer: KSerializerForBukkit<ItemMeta>(ItemMeta::class)
+object ItemStackSerializer: KSerializerForBukkit<ItemStack>(ItemStack::class)
+object LocationSerializer: KSerializerForBukkit<Location>(Location::class)
+object VectorSerializer: KSerializerForBukkit<Vector>(Vector::class)
+
+open class KSerializerForBukkit<T : ConfigurationSerializable>(
+    private val kClass: KClass<T>
+) : KSerializer<T> {
+
+    override val descriptor = ByteArraySerializer().descriptor
+
+    override fun serialize(encoder: Encoder, value: T) {
+        val bytes = ByteArrayOutputStream()
+        BukkitObjectOutputStream(bytes).use {
+            it.writeObject(value)
+        }
+        encoder.encodeSerializableValue(ByteArraySerializer(), bytes.toByteArray())
+    }
+
+    override fun deserialize(decoder: Decoder): T {
+        BukkitObjectInputStream(
+            decoder.decodeSerializableValue(ByteArraySerializer()).inputStream()
+        ).use {
+            @Suppress("UNCHECKED_CAST")
+            return it.readObject() as? T
+                ?: throw IllegalStateException("The object can not be deserialized to an object of the type ${kClass.simpleName}")
+        }
+    }
+
+}