kotlin list集合树

data class AreaSchemaManageDto(var id: Long? = null,var pid: Long? = null,var label: String? = null,var children: MutableList<AreaSchemaManageDto>? = null
) : Serializable {
}

逻辑

  fun getAll(): List<AreaSchemaManageDto> {val list: List<AreaSchemaManageDto> = transaction {AreaSchemaManageDao.all().map { it.toModelDto() }}//最终树val treeList: MutableList<AreaSchemaManageDto> = mutableListOf()//获取根节点val rootList = list.stream().filter { dto -> dto.pid == 0L }.collect(Collectors.toList())//寻找子节点rootList.forEach { treeList.add(findChildren(it, list)) }return treeList}/*** 寻找子节点*/private fun findChildren(tree: AreaSchemaManageDto, list: List<AreaSchemaManageDto>): AreaSchemaManageDto {list.stream().filter { node -> tree.id == node.pid }.collect(Collectors.toList()).forEach { node ->if (tree.children == null) {tree.children = mutableListOf()}tree.children!!.add(findChildren(node, list))}return tree}