Set Date format using Apache POI

Question

I want to set date in date format in excel file with Apache POI. The value will set in such a manner so that in Address Bar it will show in mm/dd/YYYY and in cell it will show i

Answer 1

Best approach is:

HSSFDataFormatter hdf = new HSSFDataFormatter();
System.out.println (hdf.formatCellValue(mycell));

This worked completely fine with me. This piece of code simply returns the cell in its raw form, no change at all in its format.

Answer 2

You can apply a HSSFCellStyle to the cell you need to fill. Here some code snippets from my past work, it's not intact but shows the basic idea:

HSSFRow row = sheet.createRow(0);
HSSFCell cell = row.createCell((short) 0);
cell.setCellType(HSSFCell.CELL_TYPE_NUMERIC);

SimpleDateFormat datetemp = new SimpleDateFormat("yyyy-MM-dd");
Date cellValue = datetemp.parse("1994-01-01 12:00");
cell.setCellValue(cellValue);

//binds the style you need to the cell.
HSSFCellStyle dateCellStyle = wb.createCellStyle();
short df = wb.createDataFormat().getFormat("dd-mmm");
dateCellStyle.setDataFormat(df);
cell.setCellStyle(dateCellStyle);

More infomation about date format in JDK, you should read this: http://docs.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html