POI生成excel

// create a new file
		FileOutputStream out=null;
		try {
			out = new FileOutputStream("e:/workbook.xls");
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
		// create a new workbook
		Workbook wb = new HSSFWorkbook();
		// create a new sheet
		Sheet s = wb.createSheet();
		// declare a row object reference
		Row r = null;
		// declare a cell object reference
		Cell c = null;
// create a row
int rownum=0;
		    r = s.createRow(rownum);
 // create a numeric cell
int cellnum=0;
		        c = r.createCell(cellnum);
c.setCellValue("cellvalue");
try {
			wb.write(out);
			out.close();
		} catch (IOException e) {
			e.printStackTrace();
		}

CellStyle cs = wb.createCellStyle();
Font f = wb.createFont();
f.setBoldweight(Font.BOLDWEIGHT_BOLD);
cs.setFont(f);
 c = r.createCell(cellnum);
//要先设置style再设置value
 c.setCellStyle(cs);
c.setCellValue( "boldfont" );

POI生成excel