导出到Excel

<a href="<%=request.getContextPath()%>/OUTputToExcel?id=${id}">导出到Excel </a>

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        String papid = request.getParameter("id");
        StudentExportService ses = new StudentExportService();
        List<Student> mang=findScore(papid);
        HSSFWorkbook wb = ses.export(mang);
        response.setContentType("application/vnd.ms-excel");
        response.setHeader("Content-disposition",
                "attachment;filename=studentScore.xls");
        OutputStream ouputStream = response.getOutputStream();
        wb.write(ouputStream);
        ouputStream.flush();
        ouputStream.close();

    }

public class StudentExportService {
    String[] excelHeader = { "学号", "姓名", "成绩" };

    public HSSFWorkbook export(List list) {
        HSSFWorkbook wb = new HSSFWorkbook();
        HSSFSheet sheet = wb.createSheet("Campaign");
        HSSFRow row = sheet.createRow((int) 0);
        HSSFCellStyle style = wb.createCellStyle();
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);

        for (int i = 0; i < excelHeader.length; i++) {
            HSSFCell cell = row.createCell(i);
            cell.setCellValue(excelHeader[i]);
            cell.setCellStyle(style);
            sheet.autoSizeColumn(i);
        }

        for (int i = 0; i < list.size(); i++) {
            row = sheet.createRow(i + 1);
            Student student = (Student) list.get(i);
            row.createCell(0).setCellValue(student.getStunum());
            row.createCell(1).setCellValue(student.getName());
            row.createCell(2).setCellValue(student.getScore());
        }
        return wb;
    }
}

private List<Student> findScore(String enclass) {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        List<Student> stu=new ArrayList<Student>(); 
        try {
            conn = JdbcUtils.getConnection();
            String sql = "select * from scoreview where papid=?";
            ps = conn.prepareStatement(sql);
            ps.setString(1,enclass);
            rs = ps.executeQuery();
            while (rs.next()) {
                Student p = new Student();

                p.setStunum(rs.getString("stunum"));
                p.setName(rs.getString("name"));
                p.setScore(rs.getString("score"));
                stu.add(p);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {

             JdbcUtils.close(rs, ps, conn);
            }

        return stu;
    }