Merging Two excel files as two sheets in one workbook in java

Question

I have two xlsx files at folder C:\\DemoFilesExcel\\demo1.xlsx and C:\\DemoFilesExcel\\demo2.xlsx.

I want to create a new xlsx C:\\DemoFilesExcel\\merged.xlsx that

Answer 1

This code can be used for merging two excels. It worked for me:

public static void mergeExcels(Workbook sourceExcel, Workbook destExcel) {
    for(int sheetIndex = 0; sheetIndex < sourceExcel.getNumberOfSheets(); ++sheetIndex) {
        Sheet sheet = sourceExcel.getSheetAt(sheetIndex);
        if (destExcel.getSheet(sheet.getSheetName()) != null) {
            destExcel.removeSheetAt(destExcel.getSheetIndex(sheet.getSheetName()));
        }

        Sheet outputSheet = destExcel.createSheet(sheet.getSheetName());
        copySheets(outputSheet, sheet, true);
    }

}

public static void copySheets(Sheet newSheet, Sheet sheet, boolean copyStyle) {
    int maxColumnNum = 0;
    Map styleMap = copyStyle ? new HashMap() : null;

    int i;
    List mergedRegions = new ArrayList();
    for(i = sheet.getFirstRowNum(); i <= sheet.getLastRowNum(); ++i) {
        Row srcRow = sheet.getRow(i);
        Row destRow = newSheet.createRow(i);
        if (srcRow != null) {
            copyRow(sheet, newSheet, srcRow, destRow, styleMap, mergedRegions);
            if (srcRow.getLastCellNum() > maxColumnNum) {
                maxColumnNum = srcRow.getLastCellNum();
            }
        }
    }

    for(i = 0; i <= maxColumnNum; ++i) {
        newSheet.setColumnWidth(i, sheet.getColumnWidth(i));
    }

}

public static void copyRow(Sheet srcSheet, Sheet destSheet, Row srcRow, Row destRow, Map styleMap, List mergedRegions ) {
    destRow.setHeight(srcRow.getHeight());

    for(int j = srcRow.getFirstCellNum(); j <= srcRow.getLastCellNum(); ++j) {
        if (j >= 0) {
            Cell oldCell = srcRow.getCell(j);
            Cell newCell = destRow.getCell(j);
            if (oldCell != null) {
                if (newCell == null) {
                    newCell = destRow.createCell(j);
                }

                copyCell(oldCell, newCell, styleMap);
                CellRangeAddress mergedRegion = getMergedRegion(srcSheet, srcRow.getRowNum(), (short)oldCell.getColumnIndex());
                if (mergedRegion != null) {
                    CellRangeAddress newMergedRegion = new CellRangeAddress(mergedRegion.getFirstRow(),  mergedRegion.getLastRow(), mergedRegion.getFirstColumn(), mergedRegion.getLastColumn());
                    if (isNewMergedRegion(newMergedRegion, mergedRegions)) {
                        mergedRegions.add(newMergedRegion);
                        destSheet.addMergedRegion(newMergedRegion);
                    }
                }
            }
        }
    }

}

public static void copyCell(Cell oldCell, Cell newCell, Map styleMap) {
    if (styleMap != null) {
        if (oldCell.getSheet().getWorkbook() == newCell.getSheet().getWorkbook()) {
            newCell.setCellStyle(oldCell.getCellStyle());
        } else {
            int stHashCode = oldCell.getCellStyle().hashCode();
            CellStyle newCellStyle = (CellStyle)styleMap.get(stHashCode);
            if (newCellStyle == null) {
                newCellStyle = newCell.getSheet().getWorkbook().createCellStyle();
                newCellStyle.cloneStyleFrom(oldCell.getCellStyle());
                styleMap.put(stHashCode, newCellStyle);
            }

            newCell.setCellStyle(newCellStyle);
        }
    }

    switch(oldCell.getCellType()) {
        case 0:
            newCell.setCellValue(oldCell.getNumericCellValue());
            break;
        case 1:
            newCell.setCellValue(oldCell.getStringCellValue());
            break;
        case 2:
            newCell.setCellFormula(oldCell.getCellFormula());
            break;
        case 3:
            newCell.setCellType(3);
            break;
        case 4:
            newCell.setCellValue(oldCell.getBooleanCellValue());
            break;
        case 5:
            newCell.setCellErrorValue(oldCell.getErrorCellValue());
    }

}

public static CellRangeAddress getMergedRegion(Sheet sheet, int rowNum, short cellNum) {
    for(int i = 0; i < sheet.getNumMergedRegions(); ++i) {
        CellRangeAddress merged = sheet.getMergedRegion(i);
        if (merged.isInRange(rowNum, cellNum)) {
            return merged;
        }
    }

    return null;
}

private static boolean areAllTrue(boolean... values) {
    for(int i = 0; i < values.length; ++i) {
        if (!values[i]) {
            return false;
        }
    }

    return true;
}

private static boolean isNewMergedRegion(CellRangeAddress newMergedRegion, Collection mergedRegions) {
    boolean isNew = true;
    Iterator i$ = mergedRegions.iterator();

    while(i$.hasNext()) {
        CellRangeAddress add = (CellRangeAddress)i$.next();
        boolean r1 = add.getFirstRow() == newMergedRegion.getFirstRow();
        boolean r2 = add.getLastRow() == newMergedRegion.getLastRow();
        boolean c1 = add.getFirstColumn() == newMergedRegion.getFirstColumn();
        boolean c2 = add.getLastColumn() == newMergedRegion.getLastColumn();
        if (areAllTrue(r1, r2, c1, c2)) {
            isNew = false;
        }
    }

    return isNew;
}