我正在从现有的excel文件创建一个excel文件,在新文件中进行了一些更改,例如在 Headers 中添加徽标,更改与打印相关的格式 . 我使用的是Apache POI 3.15版 . 我正在使用xlsx文件 . 现有文件有757行和47列,文件大小为294KB . 生成的文件为630KB . 但它需要大约5分钟 . 我不确定我做错了什么 . 任何建议将不胜感激 . 这是我使用的方法和代码:
- 打开模板文件进行输出(花费的时间可以忽略不计)
File file = new File("templateName.xlsx");
workbook = new XSSFWorkbook(file);
- 打开现有文件(花费的时间可以忽略不计)
File file = new File("inputFile.xlsx");
xssfWorkbook = new XSSFWorkbook(file);
- 将现有工作表中的所有单元格与单元格样式一起复制到新工作表 . 它还处理所有页面中合并的单元格和重复的 Headers (大约需要1分钟的时间)
private void copyData(XSSFSheet from, boolean repeatRow){
int length = from.getPhysicalNumberOfRows();
System.out.println("Copying " + length + " lines of data...");
int maxNumOfCols = 0;
int numOfCols;
CreationHelper createHelper = workbook.getCreationHelper();
// Get header-footer related data
getHeaderFooterData(from);
// Set header footer
setHeader(headerLeft, headerCenter);
setFooterWithDateString(footerLeft, "Page", "of");
XSSFRow dataRow, destRow;
XSSFCell cell;
for(int i=ROW_OFFSET, r=0; i<length; i++, r++){
dataRow = from.getRow(i);
if(dataRow == null) continue;
destRow = sheet.createRow(r);
destRow.setHeight(dataRow.getHeight());
//System.out.println("Height of row " + i + ":" + dataRow.getHeightInPoints());
/*
XSSFCellStyle rowStyle = destWorkbook.createCellStyle();
rowStyle.cloneStyleFrom(dataRow.getRowStyle());
destRow.setRowStyle(rowStyle);
*/
numOfCols = dataRow.getLastCellNum();
if(numOfCols > maxNumOfCols)
maxNumOfCols = numOfCols;
for(int j=0; j<numOfCols; j++){
cell = from.getRow(i).getCell(j);
if (cell!=null) {
XSSFCell destCell = destRow.createCell(j);
// Copy style from old cell and apply to new cell
XSSFCellStyle cellStyle = workbook.createCellStyle();
cellStyle.cloneStyleFrom(cell.getCellStyle());
destCell.setCellStyle(cellStyle);
// If there is a cell comment, copy. No comments for our case
/*
if (cell.getCellComment() != null) {
System.out.println("Added cell comment");
destCell.setCellComment(cell.getCellComment());
}
*/
// If there is a cell hyperlink, copy
if (cell.getHyperlink() != null) {
XSSFHyperlink link = (XSSFHyperlink) createHelper.createHyperlink(Hyperlink.LINK_URL);
link.setAddress(cell.getHyperlink().getAddress());
link.setTooltip(cell.getHyperlink().getTooltip());
destCell.setHyperlink(link);
}
// Set the cell data type
destCell.setCellType(cell.getCellType());
switch (cell.getCellType()) {
case XSSFCell.CELL_TYPE_BOOLEAN:
destCell.setCellValue(cell.getBooleanCellValue());
break;
case XSSFCell.CELL_TYPE_NUMERIC:
if(HSSFDateUtil.isCellDateFormatted(cell)){
destCell.setCellValue(cell.getDateCellValue());
}else {
destCell.setCellValue(cell.getNumericCellValue());
}
break;
case XSSFCell.CELL_TYPE_STRING:
destCell.setCellValue(cell.getRichStringCellValue());
break;
case XSSFCell.CELL_TYPE_BLANK:
//destCell.setCellValue("");
break;
case XSSFCell.CELL_TYPE_ERROR:
destCell.setCellErrorValue(cell.getErrorCellValue());
break;
case XSSFCell.CELL_TYPE_FORMULA:
destCell.setCellFormula(cell.getCellFormula());
break;
default:
destCell.setCellValue(cell.getRawValue());
break;
}
}
}
}
// set column widths
System.out.println("maxNumOfCols: " + maxNumOfCols);
for(int w=0; w<=maxNumOfCols; w++)
sheet.setColumnWidth(w, from.getColumnWidth(w));
// Process merged cells
for(int i=0; i<from.getNumMergedRegions(); i++){
//System.out.println("Merging cells");
CellRangeAddress region = from.getMergedRegion(i);
// ignore any merged region in the header/footer data section which is upto the ROW_OFFSET
if(region.getFirstRow() < ROW_OFFSET)
continue;
region.setFirstRow(region.getFirstRow() - ROW_OFFSET);
region.setLastRow(region.getLastRow() - ROW_OFFSET);
sheet.addMergedRegion(region);
}
// set repeating header row if applicable
String range = "" + String.valueOf(headerRowIndex-ROW_OFFSET) + ":" + String.valueOf(headerRowIndex-ROW_OFFSET);
if(repeatRow){
sheet.setRepeatingRows(CellRangeAddress.valueOf(range));
}
}
- 将生成的工作簿写入新文件(大约需要4分钟)
FileOutputStream outputStream = new FileOutputStream("newFileName.xlsx");
workbook.write(outputStream);
1 回答
我做了一些事情,他们改善了运行时间 . 这是我做的事情:
根据Axel Richter的建议,一旦完成,就关闭工作簿和文件流 . 谢谢阿克塞尔!
将合并单元格进程移到顶部而不是底部
使用Hashmap重用单元格样式,而不是为工作簿中的每个单元格创建单元格样式 . 以下代码显示了我是如何做到这一点的: