Spring pageable extension. Fixed current page number, reduced pageable and sorting extra fields, map function for content transformation saved

PageableLite.kt

import org.springframework.data.domain.Page

class PageLite<T>(page: Page<T>) {
    var content: List<T> = page.content
    var pageable = PageableLite(
        number = page.pageable.pageNumber + 1,
        size = page.pageable.pageSize,
        total = page.totalElements
    )

    fun <R> map(transform: (T) -> R) = PageableImpl(
        content = this.content.map { transform(it) }.toList(),
        pageable = this.pageable
    )
}

data class PageableLite(
    val number: Int,
    val size: Int,
    val total: Long
)

data class PageableImpl<T>(
    val content: List<T>,
    val pageable: PageableLite
)