Immutable Date subclass

ImDate.kt

package net.aquadc.common

import java.util.*
import kotlin.DeprecationLevel.ERROR
import kotlin.UnsupportedOperationException as UOE

/**
 * Created by mike on 17.02.17
 */

class ImDate private constructor(date: Long) : Date(date) {

    override fun clone(): ImDate = this

    @Deprecated(message = DEPRECATED, level = ERROR) override fun getYear(): Int = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun setYear(year: Int): Unit = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun getMonth(): Int = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun setMonth(month: Int): Unit = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun getDate(): Int = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun setDate(date: Int): Unit = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun getDay(): Int = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun getHours(): Int = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun setHours(hours: Int): Unit = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun getMinutes(): Int = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun setMinutes(minutes: Int): Unit = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun getSeconds(): Int = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun setSeconds(seconds: Int): Unit = throw UOE(DEPRECATED)
    /* override fun getTime(): Long = super.getTime() // okay_face.jpg */
    @Deprecated(message = IMMUTABLE, level = ERROR) override fun setTime(time: Long): Unit = throw UOE(IMMUTABLE)
    /* override fun before(`when`: Date): Boolean = super.before(`when`) */
    /* override fun after(`when`: Date): Boolean = super.after(`when`) */
    /* override fun equals(other: Any?): Boolean = super.equals(other) */
    /* override fun compareTo(other: Date): Int = super.compareTo(other) */
    /* override fun hashCode(): Int = super.hashCode() */
    /* override fun toString(): String = super.toString() */
    @Deprecated(message = DEPRECATED, level = ERROR) override fun toLocaleString(): String = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun toGMTString(): String = throw UOE(DEPRECATED)
    @Deprecated(message = DEPRECATED, level = ERROR) override fun getTimezoneOffset(): Int = throw UOE(DEPRECATED)

    companion object {
        private const val DEPRECATED = "deprecated since February 12, 1997, i. e. 20 years ago!!"
        private const val IMMUTABLE = "cannot mutate ImDate, it's immutable!"

        fun now(): ImDate =
                ImDate(System.currentTimeMillis())

        fun fromDate(date: Date): ImDate =
                date as? ImDate ?: ImDate(date.time)

        fun fromMillis(millis: Long): ImDate =
                ImDate(millis)

        fun fromSeconds(seconds: Long): ImDate =
                ImDate(1000 * seconds)
    }
}

ImDateTypeAdapterFactory.kt

package net.aquadc.common

// imports here...

object ImDateTypeAdapterFactory : TypeAdapterFactory {
    @Suppress("UNCHECKED_CAST") // :(
    override fun <T : Any?> create(gson: Gson, type: TypeToken<T>): TypeAdapter<T>? =
            if (type.rawType == ImDate::class.java) ImDateTypeAdapter as TypeAdapter<T> else null
}

object ImDateTypeAdapter : TypeAdapter<ImDate>() {
    private val dateAdapter = DateTypeAdapter()
    override fun write(out: JsonWriter, value: ImDate?) = dateAdapter.write(out, value)
    override fun read(`in`: JsonReader?): ImDate? = dateAdapter.read(`in`)?.let { ImDate.fromDate(it) }
}