Javaweb jsp servlet mysql 学生选课系统源码

package Dao; import Bean.CourseInfo; import Bean.Dbean; import Bean.StuInfo; import com.sun.org.apache.bcel.internal.generic.SIPUSH; import java.sql.*; import java.util.*; public class StuDaoImp implements StuDao { /**学生登录*/ @Override public boolean Login(String stu_name,String stu_id, String stu_pwd) { boolean flag = false; try{ Dbean.databean(); String sql = "select * from student where stu_id='"+stu_id+"'"; ResultSet rs = Dbean.executeQuery(sql); while (rs.next()){ StuInfo sin = new StuInfo(); if(rs.getString("stu_name").equals(stu_name)&&rs.getString("stu_id").equals(stu_id)&&rs.getString("stu_pwd").equals(stu_pwd)){ flag = true; } } Dbean.close(); }catch (Exception ex){ ex.printStackTrace(); System.out.println("查询失败！ 位置StuDAOImp"); } return flag; } /**学生注册*/ @Override public boolean Register(String stu_name, String stu_id, String stu_pwd, String stu_email, String stu_major, String stu_dept, String stu_phone, String stu_class) { boolean flag = false; Dbean.databean(); String exe = "select * from student where stu_id='"+stu_id+"'"; ResultSet rs = Dbean.executeQuery(exe); try{ if(rs.next()){ flag = false; }else { String sql = "insert into student (stu_name,stu_id,stu_pwd,stu_email,stu_major,stu_dept,stu_phone,stu_class,stu_course_id,stu_score) values ('"+stu_name+"','"+stu_id+"','"+stu_pwd+"','"+stu_email+"','"+stu_major+"','"+stu_dept+"','"+stu_phone+"','"+stu_class+"','','')"; int i = Dbean.executeUpdate(sql); if(i>0){ flag = true; } } }catch (Exception ex){ ex.printStackTrace(); System.out.println("注册失败！"); } return flag; } /**获取登录学生的信息集合*/ @Override public List<StuInfo> getAll(String stu_id,String stu_name) { List<StuInfo> list = new ArrayList<StuInfo>(); try{ Dbean.databean(); // String sql = "select * from student,course,teacher where student.stu_id='"+stu_id+"'"; String sql = "select * from student,course,teacher "+" where (student.stu_id = '"+stu_id+"' or student.stu_name='"+stu_name+"') "+" and student.stu_course_id=teacher.tec_course_id "+" and teacher.tec_course_id=course.cou_id"; ResultSet rs = Dbean.executeQuery(sql); while (rs.next()){ StuInfo si = new StuInfo(); si.setStu_id(rs.getString("Stu_id")); si.setStu_name(rs.getString("Stu_name")); si.setStu_email(rs.getString("Stu_email")); si.setStu_dept(rs.getString("Stu_dept")); si.setStu_major(rs.getString("Stu_major")); si.setStu_class(rs.getString("Stu_class")); si.setStu_course_id(rs.getString("Stu_course_id")); System.out.println(rs.getString("stu_course_id")); si.setCou_name(rs.getString("Cou_name")); si.setCou_address(rs.getString("Cou_address")); si.setCou_time(rs.getString("Cou_time")); si.setTec_name(rs.getString("Tec_name")); si.setCou_score(rs.getString("Cou_score")); list.add(si); } Dbean.close(); return list; }catch (Exception ex){ ex.printStackTrace(); } return null; } /**获取个人信息*/ public List<StuInfo> GetInfo(String stu_id){ List<StuInfo> li = new ArrayList<StuInfo>(); try{ Dbean.databean(); // String sql = "select * ifnull(stu_course_id,'') as stu_course_id from student where stu_id='"+stu_id+"'"; String sql = "select * from student where stu_id='"+stu_id+"'"; ResultSet rs = Dbean.executeQuery(sql); while (rs.next()){ StuInfo si = new StuInfo(); si.setStu_name(rs.getString("stu_name")); si.setStu_id(rs.getString("stu_id")); si.setStu_email(rs.getString("stu_email")); si.setStu_dept(rs.getString("stu_dept")); si.setStu_major(rs.getString("stu_major")); si.setStu_class(rs.getString("stu_class")); si.setStu_pwd(rs.getString("stu_pwd")); si.setStu_course_id(rs.getString("stu_course_id")); si.setStu_phone(rs.getString("stu_phone")); li.add(si); } Dbean.close(); return li; }catch (Exception ex){ ex.printStackTrace(); System.out.println("获取学生个人信息失败，位置StuDaoImp"); } return null; } /** 获取用户名*/ public List<StuInfo> name(String stu_id){ List<StuInfo> li = new ArrayList<StuInfo>(); try{ Dbean.databean(); String sql = "select stu_name from student where stu_id='"+stu_id+"'"; ResultSet rs = Dbean.executeQuery(sql); while (rs.next()){ StuInfo si = new StuInfo(); si.setStu_name(rs.getString("stu_name")); li.add(si); } Dbean.close(); return li; }catch (Exception ex){ ex.printStackTrace(); System.out.println("获取用户姓名失败！位置StuDaoImp"); } return null; } /**课程信息，显示在页面中*/ @Override public List<CourseInfo> ShowCourse() { List<CourseInfo> cou = new ArrayList<CourseInfo>(); Dbean.databean(); String sql = "select * from course,teacher where course.cou_id=teacher.tec_course_id"; ResultSet rs = Dbean.executeQuery(sql); try{ while (rs.next()){ CourseInfo cour = new CourseInfo(); cour.setCou_name(rs.getString("Cou_name")); cour.setCou_id(rs.getString("Cou_id")); cour.setCou_address(rs.getString("Cou_address")); cour.setCou_time(rs.getString("Cou_time")); cour.setCou_score(rs.getString("Cou_score")); cour.setTec_name(rs.getString("Tec_name")); cou.add(cour); } Dbean.close(); return cou; }catch (Exception ex){ ex.printStackTrace(); System.out.println("查询失败,位于StuDaoImp"); } return null; } /**删除已选课程*/ @Override public boolean DeleteCourse(String stu_course_id,String stu_id) { boolean flag = false; Dbean.databean(); String sql = "update student set stu_course_id='' where stu_id='"+stu_id+"'"; try{ int i = Dbean.executeUpdate(sql); if(i>0){ flag = true; } Dbean.close(); }catch (Exception ex){ ex.printStackTrace(); System.out.println("删除失败，位置StuDaoImp"); } return flag; } /**修改密码*/ @Override public boolean UpdatePws(String stu_id, String stu_pwd) { boolean flag = false; Dbean.databean(); String sql = "update student set stu_pwd='"+stu_pwd+"'"; String sq = "select * from student where stu_id='"+stu_id+"'"; ResultSet rs = Dbean.executeQuery(sq); try { if(rs.next()) { try {