java excel 设置列为日期 POI - 如何将单元格值设置为日期并应用默认Excel日期格式？...

此代码示例可用于更改日期格式 . 在这里，我想从yyyy-MM-dd改为dd-MM-yyyy . 这里 pos 是列的位置 .

import org.apache.poi.ss.usermodel.Cell;

import org.apache.poi.ss.usermodel.CellStyle;

import org.apache.poi.ss.usermodel.CreationHelper;

import org.apache.poi.ss.usermodel.Row;

import org.apache.poi.xssf.usermodel.XSSFCellStyle;

import org.apache.poi.xssf.usermodel.XSSFColor;

import org.apache.poi.xssf.usermodel.XSSFFont;

import org.apache.poi.xssf.usermodel.XSSFSheet;

import org.apache.poi.xssf.usermodel.XSSFWorkbook;

class Test{

public static void main( String[] args )

{

String input="D:\\somefolder\\somefile.xlsx";

String output="D:\\somefolder\\someoutfile.xlsx"

FileInputStream file = new FileInputStream(new File(input));

XSSFWorkbook workbook = new XSSFWorkbook(file);

XSSFSheet sheet = workbook.getSheetAt(0);

Iterator iterator = sheet.iterator();

Cell cell = null;

Row row=null;

row=iterator.next();

int pos=5; // 5th column is date.

while(iterator.hasNext())

{

row=iterator.next();

cell=row.getCell(pos-1);

//CellStyle cellStyle = wb.createCellStyle();

XSSFCellStyle cellStyle = (XSSFCellStyle)cell.getCellStyle();

CreationHelper createHelper = wb.getCreationHelper();

cellStyle.setDataFormat(

createHelper.createDataFormat().getFormat("dd-MM-yyyy"));

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

Date d=null;

try {

d= sdf.parse(cell.getStringCellValue());

} catch (ParseException e) {

// TODO Auto-generated catch block

d=null;

e.printStackTrace();

continue;

}

cell.setCellValue(d);

cell.setCellStyle(cellStyle);

}

file.close();

FileOutputStream outFile =new FileOutputStream(new File(output));

workbook.write(outFile);

workbook.close();

outFile.close();

}}