public static void main(String[] args) throws Exception {
    //创建excel
    Workbook wb = new HSSFWorkbook();
    //创建sheet
    Sheet sheet = wb.createSheet("iloveyou");
    //创建行
    Row row = sheet.createRow(0);
    //创建单元格
    Cell cell =  row.createCell(0);
    //填充元素
    cell.setCellValue("I Love You!");
    //输出流
    FileOutputStream out = new FileOutputStream("iloveyou.xls");
    //写出
    wb.write(out);
    //关闭流
    out.close();
  }

public class PoiTest1 {

  /**
   * @param args
   * @throws IOException 
   */
  public static void main(String[] args) throws IOException {
    // TODO Auto-generated method stub
    //创建excel文件
    Workbook wb = new HSSFWorkbook();
    
    CreationHelper createHelper = wb.getCreationHelper();
    
    Sheet sheet = wb.createSheet("dateSheet");
    
    Row row = sheet.createRow(0);
    
    Cell cell = row.createCell(0);
    
    cell.setCellValue(new Date());
    
    CellStyle cellStyle = wb.createCellStyle();
    cellStyle.setDataFormat(createHelper.createDataFormat().getFormat("m/d/yy h:mm"));
    
    cell = row.createCell(1);
    
    cell.setCellValue(new Date());
    
    cell.setCellStyle(cellStyle);
    
    //使用java.util.Calendar来设置单元格格式
    cell = row.createCell(2);
    cell.setCellValue(Calendar.getInstance());
    cell.setCellStyle(cellStyle);
    
    FileOutputStream fileOut = new FileOutputStream("workbook.xls");
    wb.write(fileOut);
    fileOut.close();  
  }

}

public class PoiTest7 {
  public static void main(String[] args) throws Exception {
    Workbook wb = new XSSFWorkbook();
    Sheet sheet = wb.createSheet("new sheet");
    
    Row row = sheet.createRow((short)1);
    
    CellStyle style = wb.createCellStyle();
    
    style.setFillBackgroundColor(IndexedColors.YELLOW.getIndex());
    style.setFillPattern(CellStyle.BIG_SPOTS);
    
    Cell cell = row.createCell((short)1);
    cell.setCellValue("X");
    cell.setCellStyle(style);
    
    style = wb.createCellStyle();
    
    style.setFillBackgroundColor(IndexedColors.ORANGE.getIndex());
    style.setFillPattern(CellStyle.SOLID_FOREGROUND);
    cell = row.createCell((short)2);
    cell.setCellValue("X");
    cell.setCellStyle(style);
    
    FileOutputStream fileOut = new FileOutputStream("style2.xlsx");
    wb.write(fileOut);
    fileOut.close();
    
  }
}