在jsp到处excel表格

package com.mchaha.dao.impl; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.ArrayList; import java.util.List; import com.mchaha.dao.StudentDAO; import com.mchaha.util.DBHelper; import com.mchaha.vo.Student; public class StudentDAOImpl implements StudentDAO { private Connection conn = null; public boolean checkUser(String stuname, String password) { conn = DBHelper.getConnection(); String sql = " select count(*) from student where stuname = ? and password = ? "; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(sql); ps.setString(1, stuname); ps.setString(2, password); rs = ps.executeQuery(); rs.next(); if (rs.getInt(1) > 0) { return true; } } catch (Exception e) { e.printStackTrace(); } finally { DBHelper.releaseResource(rs, ps, conn); } return false; } public List<Student> findAllStudent() { List<Student> list = new ArrayList<Student>(); conn = DBHelper.getConnection(); String sql = " select * from student"; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(sql); rs = ps.executeQuery(); while (rs.next()) { Student stu = new Student(); stu.setId(rs.getInt(1)); stu.setStuname(rs.getString(2)); stu.setPassword(rs.getString(3)); stu.setSex(rs.getString(4)); list.add(stu); } } catch (Exception e) { e.printStackTrace(); } finally { DBHelper.releaseResource(rs, ps, conn); } return list; } public void deleteStudentById(int id) { conn = DBHelper.getConnection(); String sql = " delete from student where id = ? "; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(sql); ps.setInt(1, id); ps.execute(); } catch (Exception e) { e.printStackTrace(); } finally { DBHelper.releaseResource(rs, ps, conn); } } public void addStudent(Student student) { conn = DBHelper.getConnection(); String sql = " insert into student values(?,?,?)"; PreparedStatement ps = null; try { ps = conn.prepareStatement(sql); ps.setString(1, student.getStuname()); ps.setString(2, student.getPassword()); ps.setString(3, student.getSex()); ps.execute(); } catch (Exception e) { e.printStackTrace(); } finally { DBHelper.releaseResource(ps, conn); } } public Student findStudentById(int id) { conn = DBHelper.getConnection(); String sql = " select * from student where id = ?"; PreparedStatement ps = null; ResultSet rs = null; try { ps = conn.prepareStatement(sql); ps.setInt(1, id); rs = ps.executeQuery(); if (rs.next()) { Student stu = new Student(); stu.setId(rs.getInt(1)); stu.setStuname(rs.getString(2)); stu.setPassword(rs.getString(3)); stu.setSex(rs.getString(4)); return stu; } } catch (Exception e) { e.printStackTrace(); } finally { DBHelper.releaseResource(rs, ps, conn); } return null; } public void updateStudent(Student student) { conn = DBHelper.getConnection(); String sql = " update Student set stuname = ? , password = ? , sex = ? where id = ?"; PreparedStatement ps = null; try { ps = conn.prepareStatement(sql); ps.setString(1, student.getStuname()); ps.setString(2, student.getPassword()); ps.setString(3, student.getSex()); ps.setInt(4, student.getId()); ps.execute(); } catch (Exception e) { e.printStackTrace(); } finally { DBHelper.releaseResource(ps, conn); } } }