java学生选课系统方案

1、.需求分析 ：写一个较为严谨的学生选课系统，实现学生可以选择多门选课课程，并将有效选课结果保存到数据库。学生需要登录后 ，才能选课 。让学生可以在选课系统通过多种方式查询到要选的课程信息。/ 选课规则 ： 1 、每个学生可以选多门课程 ，多次选课的总学分不能超过 6学分；2、不能重复选择一门课程 ； 3、每一门课程的选课人数都有数量限制 ，当某门课程的选课名额满时 ，则应另选课程 。4、凭用户名和密码登录 ，通过提交某一课程号来选课/ 总体设计方案 ：建立三个类 ：登录类 register ，选课类 studentChooseCourse,数据库工具类JDBCUtil；一个SQL 脚本文件用于

2、生成数据库表结构和初始记录，以搭建数据库环境 。登录类 register 类，负责对用户的身份进行验证；工具类 JDBCUtil 用于实现连接，你可调用 JDBCUtil 的 getConnection() 方法等到链接 。选课类 studentChooseCourse用于，实现选课功能 。其中包括几个主要方法 ：1、 actionPerformed(ActionEvent)用于监听用户 “查询 ”和 “提交 ”操作 ，并负责调用各种方法对其进行处理2、createSearchCourse() 用于产生图形用户界面3、 processBeforeCommit() 用于对用户的 “提交 ”查找进

3、行验证 ，剔除无效的用户操作4、 tryCommit() 负责对有效的 “提交 ”操作 ，进一步处理 ，并将有效的操作结果时时保存到数据库 ，并更新数据库原有信息/ 本程序用到的知识点 ：数据库连接 JDBC； SQL 建表、插入输入 、动态查询 ；图形用户界面的产生以及处理查询结果集并较好显示 ；程序设计基础知识 。.专业专注./ 代码如下 ：publicclassStudentChooseCourseextendsJFrameimplementsActionListener JTextField jtfSearch = new JTextField(11);String columnNam

4、es = new String "课程 ID", " 课程名 ", " 学时 ", " 学分 ", "学期 ", " 性质" ;DefaultTableModel dtmSearch = new DefaultTableModel(columnNames, 27);JTable jtSearch = new JTable(dtmSearch);JScrollPane jspSearch = new JScrollPane(jtSearch);JComboBox jcbSear

5、ch = new JComboBox();JTextField jtfSelectedCourse = new JTextField(10);Connection con = null;PreparedStatement ps = null;ResultSet rs = null;.专业专注.private static String usrName;private static String passwrd;public StudentChooseCourse(String usrName, String passwrd) createSearchCourse();this.usrName

6、= usrName;this.passwrd = passwrd;public String getUsrName() return usrName;public void setUsrName(String usrName) this.usrName = usrName;public String getPasswrd() return passwrd;public void setPasswrd(String passwrd) this.passwrd = passwrd;public void actionPerformed(ActionEvent e) String str = e.g

7、etActionCommand();.专业专注.if (" 查询 ".trim().equals(str) int k = 1;while (k < 10) for (int i = 1; i < 7; i+) jtSearch.setValueAt(null, k - 1, i - 1);k+;searchAvailableCourse(); else if (" 提交 ".equals(str) boolean effect=processBeforeCommit();if(effect=true)tryCommit();public b

8、oolean processBeforeCommit()int k = 1;while (k < 10) for (int i = 1; i < 7; i+) .专业专注.jtSearch.setValueAt(null, k - 1, i - 1);k+;String userInput = jtfSelectedCourse.getText().toString().trim().toLowerCase();String sql = "select cno from coursexx where cno=? "boolean flagCourseExist

9、= false;try ps = con.prepareStatement(sql);ps.setString(1, userInput);rs = ps.executeQuery();flagCourseExist = rs.next(); catch (Exception eC) eC.printStackTrace();if (!flagCourseExist) JOptionPane.showMessageDialog(null, "该课程不存在 ，请重新输入 ");return false;PreparedStatement ps = null;.专业专注.sql

10、 = "select sum(grade) "+ "from (select x.sname , o,k.grade grade "+ "from coursexx k join choicesxx x "+ "on o=o and x.sname=?) result" String grade =null;try ps = con.prepareStatement(sql);ps.setString(1, usrName);rs = ps.executeQuery();while (rs.next() grade

11、 = rs.getString(1);if(grade=null)grade="0" catch (Exception rrr) rrr.printStackTrace();总学分：" + grade);if (Integer.parseInt(grade) > 6) JOptionPane.showMessageDialog(null, "你已经选满 6学分，系统将退出 ");this.setVisible(false);return false;.专业专注.sql = "select * from choicesxx whe

12、re sname=? and cno=?"boolean flag = false;try ps = con.prepareStatement(sql);ps.setString(1, this.getUsrName();ps.setString(2, userInput);rs = ps.executeQuery();flag = rs.next(); catch (Exception eaa) eaa.printStackTrace();if (flag) JOptionPane.showMessageDialog(null, "你已经选择了该课程 。请另选课程 &qu

13、ot;);return false;return true;public void tryCommit() String userInput = jtfSelectedCourse.getText().toString().trim().toLowerCase();PreparedStatement ps;.专业专注.String sql = "select (Max-selectedCount) as RemainedCount "+ "from Coursexx where cno=?" try ps = con.prepareStatement(s

14、ql); ps.setString(1, userInput);rs = ps.executeQuery();ResultSetMetaData meta = rs.getMetaData();int cols = meta.getColumnCount();int RemainedCount = -1;while (rs.next() RemainedCount = rs.getInt(1);if (RemainedCount > 0) sql = "insert into choicesxx values(?,?)"ps = con.prepareStatemen

15、t(sql);ps.setString(1, this.getUsrName();ps.setString(2, userInput);ps.executeUpdate();JOptionPane.showMessageDialog(null, "选课成功 ： " + this.getUsrName()+ "选了 " + userInput + "." + "" + "还有 " + RemainedCount+ " 人可以选该课程 。");.专业专注.sql = "

16、update CourseXX set selectedCount=selectedCount+1 where cno=?"ps = con.prepareStatement(sql);ps.setString(1, userInput);ps.executeUpdate();mit(); catch (Exception es) es.printStackTrace(); try con.rollback(); catch (Exception ey) ey.printStackTrace();public void searchAvailableCourse() if (JDBC

17、Util.getConnection() != null) con = JDBCUtil.getConnection(); else con = JdbcUtil.getConnection();.专业专注.String userInput = jtfSearch.getText().toString().trim().toLowerCase();String selectedItem = jcbSearch.getSelectedItem().toString().trim();String sql = null;try if (" 课程名 ".equals(select

18、edItem) sql = "select cno,cname,hour,grade,term,isNeed from CourseXX where cname= ?"ps = con.prepareStatement(sql);ps.setString(1, userInput); else if (" 课程 ID".equals(selectedItem) sql = "select cno,cname,hour,grade,term,isNeed from CourseXX where cno= ?"ps = con.prepa

19、reStatement(sql);ps.setString(1, userInput); else if (" 学时 ".equals(selectedItem) sql = "select cno,cname,hour,grade,term,isNeed from CourseXX where hour= ?"ps = con.prepareStatement(sql);ps.setInt(1, Integer.parseInt(userInput);.专业专注. else if (" 学分 ".equals(selectedIte

20、m) sql = "select cno,cname,hour,grade,term,isNeed from CourseXX where grade= ?"ps = con.prepareStatement(sql);ps.setInt(1, Integer.parseInt(userInput); else if (" 学期 ".equals(selectedItem) sql = "select cno,cname,hour,grade,term,isNeed from CourseXX where term= ?"ps = c

21、on.prepareStatement(sql);ps.setString(1, userInput);rs = ps.executeQuery();mit();ResultSetMetaData meta = rs.getMetaData();int cols = meta.getColumnCount();String result = null;int k = 1;boolean flag = false;while (rs.next() for (int i = 1; i <= cols; i+) result = rs.getString(i);.专业专注.jtSearch.s

22、etValueAt(result, k - 1, i - 1);k+;flag = true;if (flag = false) JOptionPane.showMessageDialog(null, "该课程不存在 ，请重新输入 ");return; catch (Exception ex) ex.printStackTrace();try con.rollback(); catch (Exception er) er.printStackTrace();public void createSearchCourse() this.setLayout(new GridLay

23、out(3, 1);JPanel jp1 = new JPanel();jp1.setLayout(new GridLayout(4, 1);JPanel jp2 = new JPanel();.专业专注.JPanel jp3 = new JPanel();JPanel jp10 = new JPanel();JPanel jp11 = new JPanel();JPanel jp12 = new JPanel();JPanel jp13 = new JPanel();JLabel jlSearch = new JLabel("学 生 选 课 系 统 ");jp11.add

24、(jlSearch);jcbSearch.addItem(new String("课程名 ");jcbSearch.addItem(new String("课程 ID");jcbSearch.addItem(new String("学时 ");jcbSearch.addItem(new String("学分 ");jcbSearch.addItem(new String("学期 ");jp12.add(jtfSearch);jp12.add(jcbSearch);JButton jbOK = n

25、ew JButton("查询 ");jbOK.addActionListener(this);jbOK.setSize(90, 20);jp13.add(jbOK);jp1.add(jp10);jp1.add(jp11);jp1.add(jp12);jp1.add(jp13);.专业专注.jp2.add(jspSearch);JLabel jlSelectedCourse = new JLabel("请输入课程 ID： ");JButton jbSelectedCourse = new JButton("提交 ");jbSelecte

26、dCourse.addActionListener(this);jp3.add(jlSelectedCourse);jp3.add(jtfSelectedCourse);jp3.add(jbSelectedCourse);this.add(jp1);this.add(jp2);this.add(jp3);this.setVisible(true);this.setSize(485, 600);public static void main(String args) /String usrName = "xuliang"/String passwrd = "123&

27、quot;new StudentChooseCourse(usrName, passwrd);drop table registerXu;createtableregisterXu(idvarchar(20),userNamevarchar(20),passWordvarchar(20),identify varchar(20);.专业专注.insert into registerXu values('s001','xuliang','123','学生 ');insert into registerXu values('s

28、002','xuliang2','1234','学生 ');insert into registerXu values('j001','jack','12345','学生 ');insert into registerXu values('001','user','user','学生 ');insert into registerXu values('z001','zlm',

29、9;corejava','老师 ');String sql = "select * from registerXu "+ "where userName=? and passWord=? and identify=?" /table 2:Coursexx 课程表drop table Coursexx;create table Coursexx(cno varchar(20) primary key,cname varchar(20),hour Int,grade Int,term varchar(20),isNeed varcha

30、r(20), selectedCount Int ,Max Int);insert into Coursexx values('c001','CoreJava',50,5,'201007','NoNecessary',0,50);insert into Coursexx values('c002','XML',20,2,'201008','NoNecessary',0,40);insertintoCoursexxvalues('c003','H

31、IBERNATE',20,4,'201008','NoNecessary',0,30);insert into Coursexx values('c004','SQL',20,4,'201006','NoNecessary',0,5);insert into Coursexx values('c005','JDBC',20,2,'201008','NoNecessary',0,3);insert into Coursexx va

32、lues('c006','AJAX',20,2,'201010','NoNecessary',0,1);insert into Coursexx values('c007','JSP',100,8,'201009','NoNecessary',0,1sql = "select cno,cname,hour,grade,term,isNeed from CourseXX where cname= ?".专业专注./table 3: 学生表 -drop

33、 table studentxx;createtablestudentxx(sidvarchar(20),snamevarchar(20)primarykey,sexvarchar(20),birthday varchar(20),className varchar(20), image varchar(20);insert into studentxx values('s001','xuliang','male','19901124','sd1003','good');insertintostud

34、entxxvalues('s002','xuliang2','male','19851124','sd0910','good');insert into studentxx values('j001','jack','male','19881124','sd1003','good');insert into studentxx values('001','user',

35、9;male','19901124','sd1005','good');insert into studentxx values('s003','sisi','female','19880124','sd1007','good');insertintostudentxxvalues('as003','crystal','female','19880124','asd1007

36、','good');drop table choicesxx;create table choicesxx(sname varchar(20)referencesstudentxx(sname),cnovarchar(20)referencescoursexx(cno);package school;.专业专注.public class Register implements ActionListener JFrame jf = new JFrame("学生成绩管理与选课系统");JTextField jtfUserName = new JTextF

37、ield(10);JPasswordField jpfPassWord = new JPasswordField(10);JComboBox identify = new JComboBox();public Register() CreateRegisterGUI();public void actionPerformed(ActionEvent e) String str = e.getActionCommand();if (str.equalsIgnoreCase(" 登录 ") processLogin(); else if (str.equalsIgnoreCas

38、e(" 取消 ") jtfUserName.setText("");jpfPassWord.setText(""); else if (str.equalsIgnoreCase(" 注册 ") new CreateLogin();public void processLogin() .专业专注.Connection con = null;if (JdbcUtil.class = null) con = JdbcUtil.getConnection(); else con = JDBCUtil.getConnecti

39、on();String usrName = jtfUserName.getText().trim();String passwrd = new String(jpfPassWord.getPassword().trim();String ident = identify.getSelectedItem().toString().trim();String sql = "select * from registerXu "+try PreparedStatement ps = con.prepareStatement(sql);ps.setString(1, usrName)

40、;ps.setString(2, passwrd);ps.setString(3, ident);.专业专注.ResultSet rs = ps.executeQuery();StringBuffer sb = new StringBuffer("");ResultSetMetaData meta = rs.getMetaData();int cols = meta.getColumnCount();records in database:while (rs.next() for (int i = 1; i < cols; i+) sb.append(meta.get

41、ColumnName(i);sb.append(rs.getString(i);if (sb.length() < 1) JOptionPane.showMessageDialog(null, "用户名或密码错误 "); else if (sb.length() >= 1) if (ident.equals("student") new StudentChooseCourse(usrName, passwrd); jf.setVisible(false); else if (ident.equals("teacher")

42、new TeacherEntered();jf.setVisible(false);.专业专注. else if (ident.equals("admin") catch (Exception er) er.printStackTrace();public void CreateRegisterGUI() jf.setLayout(new GridLayout(5, 1);JPanel jp1 = new JPanel();JLabel jl1 = new JLabel("学生成绩管理系统 ");jp1.add(jl1);jf.add(jp1);JPan

43、el jp2 = new JPanel();JLabel jl2 = new JLabel("用户名 :");jp2.add(jl2);jp2.add(jtfUserName);jf.add(jp2);JPanel jp3 = new JPanel();JLabel passWord = new JLabel("密 码 :");jp3.add(passWord);.专业专注.jp3.add(jpfPassWord);jf.add(jp3);JPanel jp4 = new JPanel();JLabel jl4 = new JLabel("身 份:");/ identify.addItem(new String(" 学生 "); identify.addItem(new S