Java完整的学生选课系统源码
//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。
//代码如下：
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.*;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import school.schoolPicture.JdbcUtil;
public class StudentChooseCourse extends JFrame implements ActionListener {
JTextField jtfSearch = new JTextField(11);
String[] columnNames = 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 jcbSearch = new JComboBox();
JTextField jtfSelectedCourse = new JTextField(10);
Connection con = null;
PreparedStatement ps = null;
ResultSet rs = null;
private static String usrName;
private static String passwrd;
//在构造方法中添加两个参数。以便在"提交"时，将学生的身份连同所选的课程，一同记录在学生选课表中。
public StudentChooseCourse(String usrName, String passwrd) {
createSearchCourse();
https://www.sodocs.net/doc/d55865655.html,rName = usrName;
this.passwrd = passwrd;
}
public String getUsrName() {
return usrName;
}
public void setUsrName(St
ring usrName) {
https://www.sodocs.net/doc/d55865655.html,rName = usrName;
}
public String getPasswrd() {
return passwrd;
}
public void setPasswrd(String passwrd) {
this.passwrd = passwrd;
}
文章转自Java中文网:https://www.sodocs.net/doc/d55865655.html,/other/code/282094.shtml
//根据用户的时间，做出相应的反映
public void actionPerformed(ActionEvent e) {
String str = e.getActionCommand();
//清空结果显示区中的内容，如果有的话。
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++;
}
//调用下面的这个方法，在数据库中进行查找，并将结果显示在表格中。
searchAvailableCourse();
} else if ("提交".equals(str)) {
//processBeforeCommit()对用户选课操作进行有效性检验；
//剔除无效操作：如输入无效的课程号，或已经选择了某一课程，已经选满的6学分等各种情况
boolean effect=processBeforeCommit();
//如果课程存在，且该学生具有选择该课程的资格，即effect为true,进入正式提交程序(tryCommit())
if(effect==true)
{tryCommit();}
}
}
//对用户选课操作进行有效性检验；
public boolean processBeforeCommit(){
//清空原结果显示区中的内容，如果有的话。
int k = 1;
while (k < 10) {
for (int i = 1; i < 7; i++) {
jtSearch.setValueAt(null, k - 1, i - 1);
}
k++;
}
//取得用户输入的课程号
String userInput = jtfSelectedCourse.getText().toString().trim()
.toLowerCase();
//无效操作1：在数据库中的coursexx表中查询该课程号。如果不存在该课程，给出提示。
String sql = "select cno from coursexx where cno=? ";
boolean flagCourseExist = 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;
}
//判断该学生选修课已选课程的总学分是否小于6；
//无效操作2：如果已有选课记录，并且总学分大于6学分，该学生不能在选了。
PreparedStatement ps = null;
sql = "select sum(grade) "
+ "from (select x.sname , https://www.sodocs.net/doc/d55865655.html,o,k.grade grade "
+ "from coursexx k join choicesxx x "
+ "on https://www.sodocs.net/doc/d55865655.html,o=https://www.sodocs.net/doc/d55865655.html,o and x.sname=?) result";
String grade =null;
try {
ps = con.prepareStatement(sql);
ps.setString(1, usrName);
rs = ps.executeQuery();
while (rs.next()) {
grade = rs.getString(1);
if(grade==null){grade="0";}
}
} catch (Exception rrr) {
rrr.printStackTrace();
}
System.out.println("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;
}
//无效操作3：课程该学生已经选择了某课程，则不能再选该课程了。
sql = "select * from choicesxx where 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");
return false;}
//如果以上无效操作都不存在，则返回true，意为这是一个准有效操作
return true;
}
//对有效的提交操作的进行处理
public void tryCommit() {
// userInput为用户输入的课程ID.
String userInput = jtfSelectedCourse.getText().toString().trim()
.toLowerCase();
// if course still available(count
PreparedStatement ps;
String sql = "select (Max-selectedCount) as RemainedCount "
+ "from Coursexx where cno=?";
try {
ps = con.prepareStatement(sql);
// 取得学生ID或名字，将课程ID存入学生选课表choicesxx
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);
System.out.println("RemainedCount:" + RemainedCount);
}
//如果该课程还有选择的名额，提示单项选课操作成功。
if (RemainedCount > 0) {
// save studentId and courseId to student-course table.
// this.getUsrName();userInput
sql = "insert into choicesxx values(?,?)";
ps = con.prepareStatement(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。");
// 更新课程中已选该课程的人数：即将可选该课程的人数减去1个人。
sql = "update CourseXX set selectedCount=selectedCount+1 where cno=?";
ps = con.prepareStatement(sql);
ps.setString(1, userInput);
ps.executeUpdate();
https://www.sodocs.net/doc/d55865655.html,mit();
//如果该课程已经没有选择名额，提示重新选课
}
} catch (Exception es) {
es.printStackTrace();
try {
con.rollback();
} catch (Exception ey) {
ey.printStackTrace();
}
}
}
文章转自Java中文网:https://www.sodocs.net/doc/d55865655.html,/other/code/282094_2.shtml
//对用户查询课程信息，进行处理，并显示查询结果
public void searchAvailableCourse() {
// 让程序自动选择连接的是Oracle或SqlServer.
if (JDBCUtil.getConnection() != null) {
System.out.println(JDBCUtil.getConnection());
con = JDBCUtil.getConnection();
} else {
con = JdbcUtil.getConnection();
}
//userInput取得用户输入的信息,selectedItem取得用户选择的查询方式
String userInput = jtfSearch.getText().toString().trim().toLowerCase();
String selectedItem = jcbSearch.getSelectedItem().toString().trim();
System.out.println("User search:" + userInput);
System.out.println("selectedItem:" + selectedIt
em);
String sql = null;
//按用户查询方式，如按课程名，课程ID或学时的查询进行处理；并在表格中实现结果
try {
if ("课程名".equals(selectedItem)) {
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.prepareStatement(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));
} else if ("学分".equals(selectedItem)) {
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 = con.prepareStatement(sql);
ps.setString(1, userInput);
}
System.out.println(sql);
rs = ps.executeQuery();
https://www.sodocs.net/doc/d55865655.html,mit();
ResultSetMetaData meta = rs.getMetaData();
int cols = meta.getColumnCount();
String result = null;
int k = 1;
boolean flag = false;
//将查询结果以表格的形式显示出来
while (rs.next()) {
for (int i = 1; i <= cols; i++) {
result = rs.getString(i);
System.out.println(result);
jtSearch.setValueAt(result, k - 1, i - 1);
}
k++;
flag = true;
}
//如果查询结果集为空，提示用户没有该课程
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();
}
}
文章转自Java中文网:https://www.sodocs.net/doc/d55865655.html,/other/code/282094_3.shtml
//产生图形用户界面，以便用户操作
public void createSearchCourse() {
this.setLayout(new GridLayout(3, 1));
JPanel jp1 = new JPanel();
jp1.setLayout(new GridLayout(4, 1));
JPanel jp2 = new JPanel();
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(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 = new 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);
jp2.add(jspSearch);
JLabel jlSelectedCourse = new JLabel("请输入课程ID：");
JButton jbSelectedCourse = new JButton("提交");
jbSelectedCourse.addActionListener(this);
jp3.add(jlSelectedCou
rse);
jp3.add(jtfSelectedCourse);
jp3.add(jbSelectedCourse);
this.add(jp1);
this.add(jp2);
this.add(jp3);
this.setVisible(true);
this.setSize(485, 600);
}
//当某学生有效登录后，启动程序（将学生的登录信息也传过来，以便保存选课操作时使用）
public static void main(String[] args) {
//String usrName = "xuliang";
//String passwrd = "123";
new StudentChooseCourse(usrName, passwrd);
}
}
文章转自Java中文网:https://www.sodocs.net/doc/d55865655.html,/other/code/282094_4.shtml
//---以下为搭建学生选课系统的SQL脚本文件。只需运行一次，就可有完整的数据库表结构和初始记录。
//-----------------------------------------------------------------------------------------
//该脚本针对SQLserver；Oracle的SQL脚本类似，只需将将数据类型如varchar改为varchar2,int改为number等
--table1: registerXU 登录表
drop table registerXu;
create table registerXu (id varchar(20),userName varchar(20),passWord varchar(20),identify varchar(20));
insert into registerXu values('s001','xuliang','123','学生');
insert into registerXu values('s002','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','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 varchar(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);
insert into Coursexx values('c003','HIBERNATE',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 values('c006','AJAX',20,2,'201010','NoNecessary',0,1);
insert into Coursexx values('c007','JSP',100,8,'201009','NoNecessary',0,1
--sql = "select cno,cname,hour,grade,term,isNeed from CourseXX where cname = ?";
--table 3:学生表--
drop table studentxx;
create table studentxx(sid varchar(20),sname varchar(20) primary key,sex varchar(20),birthday varchar(20),
className varchar(20), image varchar(20));
insert into studentxx values('s001','xuliang','male','19901124','sd1003','good');
insert into studentxx values('s002','xuliang2','male','19851124','sd0910','good');
insert into studentxx values('j001','jack','male','19881124','sd1003','good');
insert into studentxx values('001','user','male','19901124','sd1005','good');
insert into studentxx values('s003','sisi','female','19880124','sd1007','good');
insert into studentxx values('as003','crystal','female','19880124','asd1007','good');
-
-table 4:choices学生选课表
drop table choicesxx;
create table choicesxx(
sname varchar(20) references studentxx(sname),cno varchar(20) references coursexx(cno));
--判断某一个学生已经选的课程的总学分是否小于6分
文章转自Java中文网:https://www.sodocs.net/doc/d55865655.html,/other/code/282094_5.shtml
//----------用户登录类 ---------------------------------------
//用途：验证用户是否具有登录系统的资格------------------------
package school;
import javax.swing.*;
import school.schoolPicture.JdbcUtil;
import java.sql.*;
import java.awt.*;
import java.awt.event.*;
public class Register implements ActionListener {
JFrame jf = new JFrame("学生成绩管理与选课系统");
JTextField jtfUserName = new JTextField(10);
JPasswordField jpfPassWord = new JPasswordField(10);
JComboBox identify = new JComboBox();
//constructor
public Register() {
CreateRegisterGUI();
}
// deal with user action, when user check:"登录","取消"or "注册"
public void actionPerformed(ActionEvent e) {
String str = e.getActionCommand();
if (str.equalsIgnoreCase("登录")) {
//当用户点击登录时，调用以下方法去数据库做匹配
processLogin();
} else if (str.equalsIgnoreCase("取消")) {
jtfUserName.setText("");
jpfPassWord.setText("");
} else if (str.equalsIgnoreCase("注册")) {
new CreateLogin();
}
}
文章转自Java中文网:https://www.sodocs.net/doc/d55865655.html,/other/code/282094_6.shtml
//当用户点击登录时，调用以下方法去数据库做匹配
public void processLogin() {
// create connection to the database.
Connection con = null;
// Connection con = JDBCUtil.getConnection();
//让程序自动连接相应的数据库,以避免连接数据库时频繁改动连接程序
if (JdbcUtil.class == null) {
//连接达内Oracle数据库
con = JdbcUtil.getConnection();
} else {
//连接本地SQLSERVER数据库
con = JDBCUtil.getConnection();
}
// write sql sentence
String usrName = jtfUserName.getText().trim();
String passwrd = new String(jpfPassWord.getPassword()).trim();
String ident = identify.getSelectedItem().toString().trim();
String sql = "select * from registerXu "
+ "where userName=? and passWord=? and identify=?";
System.out.println(usrName + ":" + passwrd + ":" + ident);
// create object of PreparedStatement
try {
PreparedStatement ps = con.prepareStatement(sql);
// Prepare parameter for the sql
ps.setString(1, usrName);
ps.setString(2, passwrd);
ps.setString(3, ident);
// send parameter to compiler to compile.
ResultSet rs = ps.executeQuery();
StringBuffer sb = new StringBuffer("");
ResultSetMetaData meta = rs.getMetaData();
int cols = meta.getColumnCount();
//you can use another simple way to check whether the people has records in database:
//define a boolean flag=false, if has record change it
//to true;otherwise, if flag=flase,showMessage("Input ERROR")
while (rs.next()) {
for (int i = 1; i < cols; i++) {
sb.append(meta.getColumnName(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")) {
//if he or she is a student, and usrName-passwrd alright, then go to 学生选课系统
new StudentChooseCourse(usrName, passwrd);
jf.setVisible(false);
// new StudentEntered();
} else if (ident.equals("teacher")) {
// new TeacherEntered(usrName,passwrd);
new TeacherEntered();
jf.setVisible(false);
} else if (ident.equals("admin")) {
// go to administrator pages.
}
}
} catch (Exception er) {
er.printStackTrace();
}
}
文章转自Java中文网:https://www.sodocs.net/doc/d55865655.html,/other/code/282094_7.shtml
//产生图形用户界面
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);
JPanel jp2 = new JPanel();
JLabel jl2 = new JLabel("用户名:");
jp2.add(jl2);
jp2.add(jtfUserName);
jf.add(jp2);
JPanel jp3 = new JPanel();
// JPasswordField jpfPassWord = new JPasswordField(10);
JLabel passWord = new JLabel("密 码:");
jp3.add(passWord);
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 String("student "));
// identify.addItem(new String("老师 "));
identify.addItem(new String("teacher "));
// identify.addItem(new String("管理员 "));
identify.addItem(new String("admin "));
identify.addActionListener(this);
jp4.add(jl4);
jp4.add(identify);
jf.add(jp4);
JPanel jp5 = new JPanel();
JButton enter = new JButton("登录");
enter.addActionListener(this);
JButton cancel = new JButton("取消");
cancel.addActionListener(this);
JButton regist = new JButton("注册");
regist.addActionListener(this);
jp5.add(enter);
jp5.add(cancel);
jp5.add(regist);
jf.add(jp5);
jf.setSize(400, 250);
jf.setVisible(true);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
new Register();
}
}
//--------- 选课系统多次调用到的本类JDBCUtil的getConnection方法--------------------------------
//---------通过该工具类选课系统连接到数据库。JdbcUtil类与次类似，连接的是Oracle数据库----------
import java.sql.*;
public class JDBCUtil {
public JDBCUtil() {
}
PreparedStatement ps = null;
ResultSet rs = null;
static {
String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
try {
Class.forName(driverName);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
public static Connection getConnection() {
Connection connection = null;
String url = "jdbc:sqlserver://localhost:1433; DatabaseName=master";
String user = "sa";
String password = "sd100301";
// String password="Foolish004";
try {
connection = DriverManager.getConnection(url, user, password);
connection.se
tAutoCommit(false);
System.out.println(connection);
} catch (SQLException e) {
e.printStackTrace();
}
return connection;
}
public static void main(String[] args) {
new JDBCUtil().getConnection();
}
}