java在线选课、学习系统源码

【实例简介】

Java基础 strut2框架 sqlServer数据库开发，较好的课程设计参考。可在线选课、学习。教师登录可管理自己所教课程。

【实例截图】

登录

学生登录如下：

选课程：

【核心代码】

登录验证：

public class LoginCheck {
public static String[] login(String username,String password,String teacher){
Connection con=DBUtil.getCon();
String[] str={"",""};
if("teacher".equals(teacher)){
String sql="select * from TB_Teacher where tnumber=? and password=?";
try {
PreparedStatement pre=con.prepareStatement(sql);
pre.setString(1, username);
pre.setString(2, password);
ResultSet rs=pre.executeQuery();
if(rs.next()){
String name=rs.getString("tname");

DBUtil.release(rs, pre, con);
str=new String[]{"teacher",name};
return str;
}
} catch (SQLException e) {
e.printStackTrace();
}
}else{
String sql="select * from TB_Student where snumber=? and password=?";
try {
PreparedStatement pre=con.prepareStatement(sql);
pre.setString(1, username);
pre.setString(2, password);
ResultSet rs=pre.executeQuery();
if(rs.next()){
String name=rs.getString("sname");
str=new String[]{"student",name};
DBUtil.release(rs, pre, con);
return str;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
return str;
}
}

学生相关的查询:

public class QueryStudentDao {
Connection con=null;
public ArrayList mycourse(String num){
con=DBUtil.getCon();
PreparedStatement pre=null;
ResultSet rs=null;
ArrayList< SelectCourse> courselist=new ArrayList<>();

String sql="select * from TB_SelectCourse where snumber=?";
try {
pre=con.prepareStatement(sql);
pre.setString(1, num);
rs= pre.executeQuery();
while(rs.next()){
SelectCourse cou=new SelectCourse();
String sql1="select cname from TB_Course where cnumber=?";
pre=con.prepareStatement(sql1);
pre.setInt(1, rs.getInt("cnumber"));
ResultSet rs1=pre.executeQuery();
String sql2="select tname from TB_Teacher where tnumber=?";
pre=con.prepareStatement(sql2);
pre.setString(1, rs.getString("tnumber"));
ResultSet rs2=pre.executeQuery();
String cname="";
if(rs1.next()){
cname=rs1.getString(1); //课程名
}
cou.setCname(cname);
rs2.next();
cou.setTname(rs2.getString(1)); //老师名
cou.setSnumber(rs.getString("snumber"));
cou.setCnumber(rs.getInt("cnumber"));
cou.setScore(rs.getInt("score"));
courselist.add(cou);
rs1.close();
rs2.close();
}
DBUtil.release(rs, pre, con);

} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return courselist;
}
public ArrayList<Course> initiatecourse(String snum){  //选课时初始化
ArrayList<Course> courlist=new ArrayList<>();
con=DBUtil.getCon();
String sql="select * from TB_Course where cnumber not in(select cnumber from TB_SelectCourse where snumber=?)";
PreparedStatement pre;
try {
pre = con.prepareStatement(sql);
pre.setString(1, snum);
ResultSet rs=pre.executeQuery();
while(rs.next()){
String sql1="select tname from TB_Teacher where tnumber=?";
pre=con.prepareStatement(sql1);
pre.setString(1, rs.getString("tnumber"));
ResultSet rs1=pre.executeQuery();
rs1.next();
Course cou=new Course();
cou.setTname(rs1.getString("tname"));
cou.setCname(rs.getString("cname"));
cou.setCredit(rs.getString("credit"));
cou.setPeriod(rs.getInt("period"));
cou.setCnumber(rs.getInt("cnumber"));
courlist.add(cou);
rs1.close();
pre.cancel();
}
rs.close();
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
return courlist;
}
public ArrayList<StudyLog> queryStudyLog(String snumber){
ArrayList< StudyLog> loglist=new ArrayList<>();
ArrayList< StudyLog> lolist=new ArrayList<>();
String sql="select * from TB_StudyLog where snumber=?";
con =DBUtil.getCon();
try {
PreparedStatement pre=con.prepareStatement(sql);
pre.setString(1, snumber);
ResultSet rs=pre.executeQuery();

while(rs.next()){
String sql1="select cname from TB_Course where cnumber=?";
pre=con.prepareStatement(sql1);
pre.setString(1, rs.getString("cnumber"));
ResultSet rs1=pre.executeQuery();
StudyLog stu=new StudyLog();
if(rs1.next()){
stu.setCname(rs1.getString("cname"));
}else{
stu.setCname("");
}
stu.setDate(rs.getString("date"));
stu.setStudytime(rs.getString("studytime"));
loglist.add(stu);
rs1.close();
}
DBUtil.release(rs, pre, con);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for(int i=loglist.size()-1;i>=0;i--){
lolist.add(loglist.get(i));
}
return lolist;
}
}
选课:

public class SelectCourseDao {
public void addCourse(String snumber,String cnumber){
Connection con=DBUtil.getCon();
String sql="select tnumber from TB_Course where cnumber=?";
try {
PreparedStatement pre=con.prepareStatement(sql);
pre.setString(1, cnumber);
ResultSet rs=pre.executeQuery();
rs.next();
String tnumber=rs.getString(1);
rs.close();
String sql1="insert into TB_SelectCourse values(?,?,?,?)";
pre=con.prepareStatement(sql1);
pre.setString(1, snumber);
pre.setString(2, cnumber);
pre.setString(3, tnumber);
pre.setInt(4, 0);
pre.executeUpdate();
pre.close();
con.close();

} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}