linkis-extensions/spark-excel/src/main/scala/com/webank/wedatasphere/spark/excel/package.scala

/*
 * Copyright 2019 WeBank
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.webank.wedatasphere.spark

import org.apache.poi.ss.usermodel.Row.MissingCellPolicy
import org.apache.poi.ss.usermodel.{Cell, Row}

package object excel {

  implicit class RichRow(val row: Row) extends AnyVal {

    def eachCellIterator(startColumn: Int, endColumn: Int): Iterator[Option[Cell]] = new Iterator[Option[Cell]] {
      private val lastCellInclusive = row.getLastCellNum - 1
      private val endCol = Math.min(endColumn, Math.max(startColumn, lastCellInclusive))
      require(startColumn >= 0 && startColumn <= endCol)

      private var nextCol = startColumn

      override def hasNext: Boolean = nextCol <= endCol && nextCol <= lastCellInclusive

      override def next(): Option[Cell] = {
        val next =
          if (nextCol > endCol) throw new NoSuchElementException(s"column index = $nextCol")
          else Option(row.getCell(nextCol, MissingCellPolicy.RETURN_NULL_AND_BLANK))
        nextCol += 1
        next
      }
    }

  }

}