OffsetDateTimeTypeAdapter.kt

import com.google.gson.*
import org.threeten.bp.LocalDateTime
import org.threeten.bp.OffsetDateTime
import org.threeten.bp.ZoneOffset
import org.threeten.bp.format.DateTimeFormatter
import org.threeten.bp.format.DateTimeFormatterBuilder
import org.threeten.bp.temporal.ChronoField
import java.lang.reflect.Type

/**
 * TypeAdapter используемый для конвертации строк с датой в объекты типа OffsetDateTime
 */
class OffsetDateTimeTypeAdapter : JsonSerializer<OffsetDateTime>, JsonDeserializer<OffsetDateTime> {
    override fun serialize(src: OffsetDateTime, typeOfSrc: Type, context: JsonSerializationContext): JsonElement {
        return JsonPrimitive(DateTimeFormatter.ISO_DATE_TIME.format(src))
    }

    @Throws(JsonParseException::class)
    override fun deserialize(json: JsonElement, typeOfT: Type, context: JsonDeserializationContext): OffsetDateTime {
        return LocalDateTime.parse(json.asString, FORMATTER).atOffset(ZoneOffset.UTC)
    }

    companion object {
        private const val DATE_TIME_FORMAT_PATTERN = "yyyy-MM-dd'T'HH:mm:ss"
        private val FORMATTER = DateTimeFormatterBuilder()
            .parseCaseInsensitive()
            .appendPattern(DATE_TIME_FORMAT_PATTERN)
            .optionalStart()
            .appendFraction(ChronoField.MICRO_OF_SECOND, 1, 7, true)
            .optionalEnd()
            .optionalStart()
            .appendZoneId()
            .optionalEnd()
            .optionalStart()
            .appendPattern("Z")
            .optionalEnd()
            .toFormatter()
    }
}