public class ExPortExcel {

 private ResultSet rs;
 private String strSql;

 public ExPortExcel() {

 }

 public ExPortExcel(ResultSet rs, String strSql) {
        this.rs=rs;
  this.strSql=strSql;
 }

 /**
  * @return
  */
 public ResultSet getRs() {
  return rs;
 }

 /**
  * @return
  */
 public String getStrSql() {
  return strSql;
 }

 /**
  * @param set
  */
 public void setRs(ResultSet set) {
  rs = set;
 }

 /**
  * @param string
  */
 public void setStrSql(String string) {
  strSql = string;
 }
 //导出数据到Excel
 public void getExcel(HttpServletRequest req, HttpServletResponse res,
   ExPortExcel excel) {
  //HSSFRichTextString title = new HSSFRichTextString("用户信息");

  DataDAO db = new DataDAO();
  ResultSet rs = db.getData(excel.strSql);
  // 创建Excel 文件
  HSSFWorkbook workbook = new HSSFWorkbook();
  // 创建工作区
  HSSFSheet sheet = workbook.createSheet();
  // 创建行对象
  HSSFRow row_title = sheet.createRow(0);
  // 创建标题的字体
//  HSSFFont title_font = workbook.createFont();
//  // 设置标题字体属性
//  title_font.setFontHeightInPoints((short) 8);
//  // 设置标题字体属性
//  title_font.setFontHeight((short) HSSFFont.BOLDWEIGHT_NORMAL);
//  // 设置标题字体的颜色
//  title_font.setColor((short) HSSFFont.BOLDWEIGHT_NORMAL);
//  // 创建样式
//  HSSFCellStyle title_style = workbook.createCellStyle();
//  // 设置标题样式属性
//  title_style.setFont(title_font);
//  // 创建单元格对象
//  HSSFCell cell_title = row_title.createCell((short) 1);
//  // 设置单元格样式
//  cell_title.setCellStyle(title_style);
//  // 将标题写到Excel表格中
//  cell_title.setCellValue(title);

  ArrayList list = new ArrayList();
  try {
   // 得到元数据
   ResultSetMetaData rsmd = rs.getMetaData();
   for (int j = 1; j <= rsmd.getColumnCount(); j++) {
    // 得到列名
    list.add(rsmd.getColumnName(j));
   }
  } catch (SQLException e1) {
   // TODO Auto-generated catch block
   e1.printStackTrace();
  }

  String titles[] = { "用户ID", "用户名", "联系电话", "地址" };

  // 创建行
  HSSFRow row = sheet.createRow((short)0);
  // 创建样式
  HSSFCellStyle items_style = workbook.createCellStyle();
  // 设置表头样式
  items_style.setAlignment((short) HSSFCellStyle.ALIGN_CENTER);
  // 创建字体
  HSSFFont celltbnamefont = workbook.createFont();
  // 设置表头字体属性
  celltbnamefont.setFontHeightInPoints((short) 8);
  // 设置表头字体属性
  celltbnamefont.setColor((short) HSSFFont.COLOR_RED);
  // 设置表头字体属性
  items_style.setFont(celltbnamefont);

  items_style.setWrapText(true);
  for (int i = 0; i < list.size(); i++) {

   HSSFCell cell = row.createCell((short) i);

   sheet.setColumnWidth((short) i, (short) 5335);

   cell.setCellStyle(items_style);

   cell.setCellValue(list.get(i).toString());
  }

  HSSFCellStyle datestyle = workbook.createCellStyle();
  HSSFDataFormat df = workbook.createDataFormat();
  datestyle.setDataFormat(df.getFormat("yyyy-mm-dd"));
  int i = 0;
  try {
   while (rs.next()) {
    // 创建行
    HSSFRow datarow = sheet.createRow((short) i + 1);
    // 创建样式
    HSSFCellStyle data_style = workbook.createCellStyle();
    // 创建字体
    HSSFFont data_font = workbook.createFont();
    // 设置字体大小
    data_font.setFontHeightInPoints((short)10);
    
    // 设置字体颜色
    data_font.setColor((short) HSSFFont.COLOR_NORMAL);
    // 设置样式居中
    data_style.setAlignment((short) HSSFCellStyle.ALIGN_CENTER);

    data_style.setFont(data_font);
    data_style.setWrapText(true);

    for (int j = 1; j < 5; j++) {
     HSSFCell cell = datarow.createCell((short) (j - 1));
     //设置单元格中的数据类型为String
     cell.setCellType(HSSFCell.CELL_TYPE_STRING);
     //设置单元格的字符编码为utf
     cell.setEncoding(HSSFCell.ENCODING_UTF_16);
     String data = rs.getString(j);
     cell.setCellStyle(data_style);
     cell.setCellValue(data);
    }
    i++;
   }
  } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  FileOutputStream out;
  OutputStream os;
  String fileName = "userinfo.xls";
  try {
   //
   res.setContentType("application/x-msdownload");
   res.setHeader("Content-Disposition", "attachment;" + " filename="
     + new String(fileName.getBytes(), "ISO-8859-1"));
   os = res.getOutputStream();
   workbook.write(os);
   os.close();

  } catch (FileNotFoundException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }

 }
}