JDBC Desktop Application 

Clear Button Coding 

 private void jButton1ActionPerformed(java.awt.event.ActionEvent evt)    {                                         

        jTextField1.setText(" ");

        jTextField2.setText(" ");

        jTextField3.setText(" ");

        jTextField4.setText(" ");

 }    

Create a Table :

create table hostellers(id varchar(100), name varchar(100), block varchar(100), roomnumber varchar(100))

JButton2 Coding 

 private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         

       try{

       // Loading Driver

        Class.forName("com.mysql.cj.jdbc.Driver");

        //Creating Connection

         Connection con =DriverManager.getConnection("jdbc:mysql://172.16.100.8/rkmishradb","rkmishra","a");

        // Create Statement

        Statement stmt =con.createStatement();

        // Storing Values to String avraible 

        String id=jTextField1.getText();

        String name=jTextField2.getText();

        String block =jTextField3.getText();

        String room =jTextField4.getText(); 

        // Execute Query 

        stmt.executeUpdate("insert into hostellers values('"+id+"','"+name+"','"+block+"','"+room+"' )");

        JOptionPane.showMessageDialog(null, "Data Successfully Saved");

        }

        catch(Exception e)

        {

             JOptionPane.showMessageDialog(null, "Something Wrong" + e);

        }

    }          

JButton3 for Update  

private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                         

        try{

       // Loading Driver

        Class.forName("com.mysql.cj.jdbc.Driver");

        //Creating Connection

         Connection con =DriverManager.getConnection("jdbc:mysql://172.16.100.8/rkmishradb","rkmishra","a");

        // Create Statement

        Statement stmt =con.createStatement();

        // Storing Values to String avraible 

        String id=jTextField1.getText();

        String name=jTextField2.getText();

        String block =jTextField3.getText();

        String room =jTextField4.getText(); 

        // Execute Query 

        stmt.executeUpdate("update hostellers set name='"+name+"',block='"+block+"', roomnumber='"+room+"'");

        JOptionPane.showMessageDialog(null, "Data Successfully Updated");

        }

        catch(Exception e)

        {

             JOptionPane.showMessageDialog(null, "Something Wrong" + e);

        }

    }                                        

JButton4 Display  

private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {                                         

        try{

       // Loading Driver

        Class.forName("com.mysql.jdbc.Driver");

        //Creating Connection

        Connection con=DriverManager.getConnection("jdbc:mysql://172.16.100.8/rkmishradb","rkmishra","a");

        // Create Statement

        Statement stmt =con.createStatement();

        // Execute Query 

       ResultSet rs= null;

               rs=stmt.executeQuery("select *from hostellers");

       DefaultTableModel tm=(DefaultTableModel)jTable1.getModel();

       tm.setRowCount(0);

       while(rs.next())

       {           

           Object o[]={rs.getString(1),rs.getString(2),rs.getString(3), rs.getString(4)};

           tm.addRow(o);

       }

        }

        catch(Exception e)

        {

             JOptionPane.showMessageDialog(null, "Something Wrong" + e);

        }

    }