How to Create Login Attempts Limit Form in Java Using NetBeans IDE and MySQL?[With Source Code]

watch the video for the whole procedure and designing part:

write the following code inside the class:

    Connection con = null;
    PreparedStatement pst = null;
    ResultSet rs = null;
    int attempt =1;

Write the following code inside the listening event of button:

       
        String sql = "select * from mysqllimitnew where username = ? and password=?";
        if(attempt<4){
        try{
            con = DriverManager.getConnection("jdbc:mysql://localhost/mysqllimitnew", "root", "");
            pst = con.prepareStatement(sql);
            pst.setString(1, txtuser.getText());
            pst.setString(2, txtpass.getText());
            rs=pst.executeQuery();
            if(rs.next()){
            JOptionPane.showMessageDialog(null,"username and password matched"+attempt);
            }else
            {
            JOptionPane.showMessageDialog(null, "error"+attempt);}
            
            
        }
        catch(Exception ex){
        JOptionPane.showMessageDialog(null, ex);}
        }
        else if(attempt!=4){
            JOptionPane.showMessageDialog(null,"try once again"+attempt);
        }
        else{
        JOptionPane.showMessageDialog(null,"exceed"+attempt);
        txtuser.setEnabled(false);
        txtpass.setEditable(false);
        }
        if(attempt==5){
            this.dispose();
        }
        attempt++;
       
 

watch the video:

How to Create Login Attempts Limit Form in Java Using NetBeans IDE?[With Source Code]

watch the video for the designing part!
write the following code inside the click event of the button:

Declare following variable inside the class but outside the click event of the button as:

         int attemtp=1;

        String user = txtuser.getText();
        String pass = txtpass.getText();
        if(attempt <4 && user.equals("TSN") && pass.equals("TSN")){
        JOptionPane.showMessageDialog(null, "accessed!");
        }
        else if(attempt!=4){
            JOptionPane.showMessageDialog(null, "denied"+attempt);
        }
        else
        {
        JOptionPane.showMessageDialog(null, "attempt exceed!"+attempt);
        txtuser.setEditable(false);
        txtpass.setEnabled(false);
        }
        if(attempt==5){
        this.dispose();
        }
        attempt++;
    }

Watch the video:

How to Show jTable Selected Row into jTextField in java?[With Source Code]

Before doing this, you need to watch this video!

watch the designing part in the video section given below:

Connection code:
    Connection con = null;
    PreparedStatement pst = null;
    ResultSet rs = null;

First create one function showTableData() and write the following code inside this function!

       
    try{
         con = DriverManager.getConnection("jdbc:mysql://localhost/combobox","root","");
         String sql = "SELECT * FROM combobox";
         pst = con.prepareStatement(sql);
         rs=pst.executeQuery();
         jTable2.setModel(DbUtils.resultSetToTableModel(rs));
 }
     catch(Exception ex){
         JOptionPane.showMessageDialog(null, ex);
         
     }
       
 

Call this function inside the constructor of the class! i.e. in the next line of initComponents();

now create the mouse clicked event of the jtable and write the following code!

       
    try{
            con = DriverManager.getConnection("jdbc:mysql://localhost/combobox","root","");
            int row = jTable2.getSelectedRow();
            String tblclick = (jTable2.getModel().getValueAt(row, 0).toString());
            String sql = "select * from combobox where Rollno ="+tblclick+"";
            pst = con.prepareStatement(sql);
            rs=pst.executeQuery();
            if(rs.next())
            {
                String Roll = String.valueOf(rs.getInt("Rollno"));
                jTextField1.setText(Roll);
                String firstname = rs.getString("fname");
                jTextField2.setText(firstname);
                String lastname = rs.getString("lname");
                jTextField3.setText(lastname);
                String add = rs.getString("address");
                jTextField4.setText(add);
            }
        }
        catch(Exception ex)
        {
            JOptionPane.showMessageDialog(null, ex);
        }
       
 

You need to import two library file mysql connector and rs2xml jar file. The link of that file is provided in the video description section.

Watch the video:

How to Connect jComboBox with Database in java?[With Source Code]

watch the video for the designing part!

write the following code inside the class:

    Connection con = null;
    PreparedStatement pst = null;
    ResultSet rs = null;

Create one function and write the following code inside that function!

       
    try
        {
            con= DriverManager.getConnection("jdbc:mysql://localhost/combobox", "root","");
            String sql = "select * from combobox ";
            pst = con.prepareStatement(sql);
            rs = pst.executeQuery();
            while(rs.next())
            {
                String name = rs.getString("fname");
                jComboBox1.addItem(name);
            }
            
        }catch(Exception ex)
        {
            JOptionPane.showMessageDialog(null, ex);
        }
       
 

call this function inside the constructor of that class i.e. under the initComponents();

 Watch The Video:

How to Create a Login Form in Java with MySQL Database using NetBeans IDE?[With Source Code]

see the designing part and library connection part in video:

Source Code:
Connection code inside the class!

    Connection con = null;
    PreparedStatement pst =null;
    ResultSet rs = null;


Code Inside the login button!

       
    String sql="select * from login where username=? and password=?";
        try{
            con = DriverManager.getConnection("jdbc:mysql://localhost/testsql","root","");
            pst=con.prepareStatement(sql);
            pst.setString(1, user.getText());
            pst.setString(2,pass.getText());
            rs=pst.executeQuery();
            if(rs.next())
            {
                JOptionPane.showMessageDialog(null,"username and password matched");
                
            }
            else
            {
                JOptionPane.showMessageDialog(null, "username and password do not matched");
            }}
            catch(SQLException | HeadlessException ex)
                    {
                    JOptionPane.showMessageDialog(null,ex);
                    }
       
 

Watch the video: