Java AbstractSpliterator vs Kotlin Sequence

AbstractSpliterator_Sequence.kt

class JsonObjectSpliterator<T>(
    private val mapper: ObjectMapper,
    private val inputStream: InputStream,
    private val clazz: Class<T>
) : Spliterators.AbstractSpliterator<T>(Long.MAX_VALUE, NONNULL or IMMUTABLE) {
    private val parser: JsonParser by lazy {
        mapper.createParser(inputStream.reader(Charsets.UTF_8)).also {
            check(it.nextToken() === JsonToken.START_ARRAY) { "Expected content to be an array" }
        }
    }

    override fun tryAdvance(action: Consumer<in T>): Boolean {
        if (parser.nextToken() === JsonToken.END_ARRAY) return false

        action.accept(mapper.readValue(parser, clazz))
        return true
    }
}

fun <T> InputStream.toObjectStream(clazz: Class<T>): Stream<T> {
    return StreamSupport.stream(JsonObjectSpliterator(ObjectMapper(), this, clazz), false)
}

fun test2() {
    inputStream.toObjectStream(Product::class.java).forEach { product ->
        logger.debug { product }
    }
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

fun <T> InputStream.toObjectSequence(clazz: Class<T>): Sequence<T> {
    val mapper = ObjectMapper()
    val parser: JsonParser = mapper.createParser(this.reader(Charsets.UTF_8))
    check(parser.nextToken() === JsonToken.START_ARRAY) { "Expected content to be an array" }
    return sequence {
        while (parser.nextToken() !== JsonToken.END_ARRAY) {
            yield(mapper.readValue(parser, clazz))
        }
    }
}

fun test2() {
    inputStream.toObjectSequence(Product::class.java).forEach { product ->
        logger.debug { product }
    }
}