org.openepics.discs.ccdb.core.util.ExcelCell.java Source code

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Here is the source code for org.openepics.discs.ccdb.core.util.ExcelCell.java

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/*
 * Copyright (c) 2014 European Spallation Source
 * Copyright (c) 2014 Cosylab d.d.
 *
 * This file is part of Controls Configuration Database.
 *
 * Controls Configuration Database is free software: you can redistribute it
 * and/or modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 2 of the License,
 * or any newer version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see https://www.gnu.org/licenses/gpl-2.0.txt
 */
package org.openepics.discs.ccdb.core.util;

import javax.annotation.Nullable;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellValue;
import org.apache.poi.ss.usermodel.FormulaEvaluator;
import org.apache.poi.ss.usermodel.Workbook;

/**
 * A static utility class for reading single Excel file cell
 *
 * @author <a href="mailto:andraz.pozar@cosylab.com">Andra Poar</a>
 */
public class ExcelCell {
    private ExcelCell() {
    }

    /**
     * Creating a String from Excel file cell. If cell contains numeric value, this value is cast to String.
     * If there is no value for this cell, null is returned.
     *
     * @param cell the Excel {@link Cell}
     * @param workbook the Excel {@link Workbook}
     *
     * @return the {@link String} result
     */
    public static String asStringOrNull(@Nullable Cell cell, Workbook workbook) {
        final String stringValue;
        if (cell != null) {
            if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
                final double numericCellValue = cell.getNumericCellValue();
                if (numericCellValue == (int) numericCellValue) {
                    stringValue = String.valueOf((int) numericCellValue);
                } else {
                    stringValue = String.valueOf(numericCellValue);
                }
            } else if (cell.getCellType() == Cell.CELL_TYPE_STRING) {
                stringValue = cell.getStringCellValue() != null ? cell.getStringCellValue() : null;
            } else if (cell.getCellType() == Cell.CELL_TYPE_BLANK) {
                stringValue = null;
            } else if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN) {
                stringValue = String.valueOf(cell.getBooleanCellValue());
            } else if (cell.getCellType() == Cell.CELL_TYPE_FORMULA) {
                final FormulaEvaluator evaluator = workbook.getCreationHelper().createFormulaEvaluator();
                final CellValue cellValue = evaluator.evaluate(cell);
                if (cellValue != null) {
                    final String columnValue = cellValue.getStringValue();
                    if (columnValue == null) {
                        stringValue = Double.toString(cellValue.getNumberValue());
                    } else {
                        stringValue = columnValue;
                    }
                } else {
                    stringValue = null;
                }
            } else {
                throw new UnhandledCaseException();
            }
        } else {
            stringValue = null;
        }
        return stringValue;
    }

    /**
     * Reading Excel file cell with numeric value and returning its value
     *
     * @param cell the Excel {@link Cell}
     *
     * @return the numeric {@link Double} value
     */
    public static double asNumber(Cell cell) {
        return cell.getNumericCellValue();
    }
}