poi自動調整寬度

I was also running into this issue and this was my solution.

Steps:

1. Create workbook
2. Create spreadsheet
3. Create row
4. Create/Set font to "Arial"
5. Create/Set style with font
6. Create/Set cell with value and style
7. autoSizeColumn
8. Create File

Code:

// initialize objects
XSSFWorkbook workbook = new XSSFWorkbook(); 
XSSFSheet spreadsheet = workbook.createSheet(sheetName);
XSSFRow row = spreadsheet.createRow(0);
XSSFCell cell;

// font/style
XSSFFont font = workbook.createFont();
font.setFontName("Arial");
XSSFCellStyle style = workbook.createCellStyle();
style.setFont(font);

// create/set cell & style
cell = row.createCell(0);
cell.setCellValue("New Cell");
cell.setCellStyle(style);

// auto size
spreadsheet.autoSizeColumn(0);

// create file
File aFile = new File("Your Filename");
FileOutputStream out = new FileOutputStream(aFile);
workbook.write(out);

Resources:

http://www.tutorialspoint.com/apache_poi/index.htm

需要設置字體

https://stackoverflow.com/questions/16943493/apache-poi-autosizecolumn-resizes-incorrectly

https://stackoverflow.com/questions/4611018/apache-poi-excel-how-to-configure-columns-to-be-expanded