Comment définir la largeur de colonne fixe dans Apache POI

Comment définir la largeur de colonne fixe dans Apache POI.
Je veux faire ma première colonne de largeur fixe.

J'ai essayé avec la feuille.setColumnWidth(0, 1000);
cellStyle.setWrapText(true); //Set wordwrap il ne reflète pas

    public XSSFWorkbook generateReport(List<Dto> result, boolean isRes, boolean isRes1) {
XSSFWorkbook workbook = null;
XSSFSheet sheet = null;
XSSFRow row = null;
XSSFCell cell = null;
String[] headers = null;
int rowNum = 0;
int colNum = 0;
CellStyle cellStyle = null;
CellStyle headerStyle = null;
XSSFFont font = null;
CellStyle datecellStyle = null;
/* set the weight of the font */
try {
workbook = new XSSFWorkbook();
headers = new String[] { ...values goes here...};
row = sheet.createRow(rowNum);
font = workbook.createFont();
font.setBoldweight(XSSFFont.BOLDWEIGHT_BOLD);
headerStyle = workbook.createCellStyle();
headerStyle.setBorderBottom(HSSFCellStyle.BORDER_MEDIUM);
headerStyle.setBorderTop(HSSFCellStyle.BORDER_MEDIUM);
headerStyle.setBorderRight(HSSFCellStyle.BORDER_MEDIUM);
headerStyle.setBorderLeft(HSSFCellStyle.BORDER_MEDIUM);
headerStyle.setFillForegroundColor((short) 200);
headerStyle.setFillPattern(XSSFCellStyle.SOLID_FOREGROUND);
headerStyle.setFont(font);
cellStyle = workbook.createCellStyle();
cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
datecellStyle = workbook.createCellStyle();
datecellStyle.setDataFormat(workbook.getCreationHelper().createDataFormat().getFormat("dd-MMM-yyyy"));
datecellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
datecellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
datecellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
datecellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
/**
* Writing Headers
*/
for (String header : headers) {
cell = row.createCell(colNum);
cell.setCellValue(header);
cell.setCellStyle(headerStyle);
++colNum;
}
/**
* Writing Other Rows
*/
SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss");
for (Dto detail : result) {
++rowNum;
colNum = 0;
row = sheet.createRow(rowNum);
cell = row.createCell(colNum);
//sheet.setColumnWidth(0, 4000);
cell.
if(null != detail.getGid()){
cell.setCellValue(detail.getGid());
}else{
cell.setCellValue("-");
}
cell.setCellStyle(cellStyle);
++colNum;
cell = row.createCell(colNum);
if(null != detail.getName()){
cell.setCellValue(detail.getName());
}else{
cell.setCellValue("-");
}
cell.setCellStyle(cellStyle);
++colNum;
cell = row.createCell(colNum);
if(null != detail.getNGid()){
cell.setCellValue(detail.getNGid());
}else{
cell.setCellValue("-");
}
cell.setCellStyle(cellStyle);
++colNum;
cell = row.createCell(colNum);
if(null != detail.getName()){
cell.setCellValue(detail.getName());
}else{
cell.setCellValue("-");
}
cell.setCellStyle(cellStyle);
}
for (int i = 0; i < headers.length; i++) {
sheet.autoSizeColumn(i);
}
sheet.createFreezePane(1, 1);
} catch (Exception e) {
e.printStackTrace();
}
return workbook;
}