title: JTextField is not updated by clicking button
body: <p>In my java project, I want to see each student's info by entering roll number. When at first time, I enter roll number, the result comes. But if I want to see other student's roll number in same window, the result is no come. What's the problem in my code? The screen shot is given below:when I change roll number, the image and other info is not updated.</p>
  
  <p><img src="https://i.stack.imgur.com/2u3Sz.jpg" alt="enter image description here"></p>
  
  <pre><code>    public void actionPerformed(ActionEvent e)
      if(e.getSource()==button)
      {
  
      l1= new JLabel("Name: ");
      l1.setForeground(Color.white);
      l1.setFont(new Font("Serif", Font.BOLD, 15));
      l1.setBounds(100,100,150,20);
      //l1.setLabelFor(tf1);
  
      l2= new JLabel("Mobile Number: ");
      l2.setForeground(Color.white);
      l2.setFont(new Font("Serif", Font.BOLD, 15));
      l2.setBounds(100,150,150,20);
      //l1.setLabelFor(tf2);
  
      l3= new JLabel("Father's Name: ");
      l3.setForeground(Color.white);
      l3.setFont(new Font("Serif", Font.BOLD, 15));
      l3.setBounds(100,200,150,20);
  
      l4= new JLabel("Mobile Number: ");
      l4.setForeground(Color.white);
      l4.setFont(new Font("Serif", Font.BOLD, 15));
      l4.setBounds(100,250,150,20);
  
      l5= new JLabel("Mother's Name: ");
      l5.setForeground(Color.white);
      l5.setFont(new Font("Serif", Font.BOLD, 15));
      l5.setBounds(100,300,150,20);
  
      l6= new JLabel("Mobile Number: ");
      l6.setForeground(Color.white);
      l6.setFont(new Font("Serif", Font.BOLD, 15));
      l6.setBounds(100,350,150,20);
  
      l7= new JLabel("Village: ");
      l7.setForeground(Color.white);
      l7.setFont(new Font("Serif", Font.BOLD, 15));
      l7.setBounds(100,400,150,20);
  
      l8= new JLabel("Police Station: ");
      l8.setForeground(Color.white);
      l8.setFont(new Font("Serif", Font.BOLD, 15));
      l8.setBounds(100,450,150,20);
  
      l9= new JLabel("District: ");
      l9.setForeground(Color.white);
      l9.setFont(new Font("Serif", Font.BOLD, 15));
      l9.setBounds(100,500,150,20);
  
      l10= new JLabel("Blood Group: ");
      l10.setForeground(Color.white);
      l10.setFont(new Font("Serif", Font.BOLD, 15));
      l10.setBounds(100,550,150,20);
  
      l11= new JLabel("Department: ");
      l11.setForeground(Color.white);
      l11.setFont(new Font("Serif", Font.BOLD, 15));
      l11.setBounds(600,100,150,20);
  
      l12= new JLabel("Series: ");
      l12.setForeground(Color.white);
      l12.setFont(new Font("Serif", Font.BOLD, 15));
      l12.setBounds(600,150,150,20);
  
      l13= new JLabel("Roll Number: ");
      l13.setForeground(Color.white);
      l13.setFont(new Font("Serif", Font.BOLD, 15));
      l13.setBounds(600,200,150,20);
  
      l14= new JLabel("CGPA: ");
      l14.setForeground(Color.white);
      l14.setFont(new Font("Serif", Font.BOLD, 15));
      l14.setBounds(600,250,150,20);
  
      l15= new JLabel("Room Number: ");
      l15.setForeground(Color.white);
      l15.setFont(new Font("Serif", Font.BOLD, 15));
      l15.setBounds(600,300,150,20);
  
  
  
  
  
      tf1= new JTextField();
      tf1.setBounds(300,100,200,20);
  
      tf2= new JTextField();
      tf2.setBounds(300,150,200,20);
  
      tf3= new JTextField();
      tf3.setBounds(300,200,200,20);
  
      tf4= new JTextField();
      tf4.setBounds(300,250,200,20);
  
      tf5= new JTextField();
      tf5.setBounds(300,300,200,20);
  
      tf6= new JTextField();
      tf6.setBounds(300,350,200,20);
  
      tf7= new JTextField();
      tf7.setBounds(300,400,200,20);
  
      tf8= new JTextField();
      tf8.setBounds(300,450,200,20);
  
      tf9= new JTextField();
      tf9.setBounds(300,500,200,20);
  
      tf10= new JTextField();
      tf10.setBounds(300,550,200,20);
  
      tf11= new JTextField();
      tf11.setBounds(710,100,200,20);
  
      tf12= new JTextField();
      tf12.setBounds(710,150,200,20);
  
      tf13= new JTextField();
      tf13.setBounds(710,200,200,20);
  
      tf14= new JTextField();
      tf14.setBounds(710,250,200,20);
  
      tf15= new JTextField();
      tf15.setBounds(710,300,200,20);
  
  
  
      tf1.setEditable(false);
      tf2.setEditable(false);
      tf3.setEditable(false);
  
      tf4.setEditable(false);
      tf5.setEditable(false);
      tf6.setEditable(false);
  
      tf7.setEditable(false);
      tf8.setEditable(false);
      tf9.setEditable(false);
  
      tf10.setEditable(false);
      tf11.setEditable(false);
      tf12.setEditable(false);
  
      tf13.setEditable(false);
      tf14.setEditable(false);
      tf15.setEditable(false);
  
  
  
  
  
  
      try {  
  
          Class.forName("com.mysql.jdbc.Driver");  
  
          Connection con=DriverManager.getConnection(  
          "jdbc:mysql://localhost:3306/hostel_management","root","");  
  
          //here project is database name, root is username and password is empty 
  
          Statement stmt=con.createStatement();  
  
          ResultSet rs=stmt.executeQuery("select * from student_info where roll_no = '" + textfield.getText() + "'");  
  
          //if(rs.next()=null)
              //JOptionPane.showMessageDialog(null, "No Available Seat. Please Select Another Room.", "Warning", JOptionPane.ERROR_MESSAGE);
          int count= 0;
  
  
  
  
  
  
  
  
  
  
          while(rs.next())  
          {
  
               count++;
  
  
               tf1.setText(rs.getString(1));
               tf1.setHorizontalAlignment(JTextField.CENTER);
  
               tf2.setText(rs.getString(2));
               tf2.setHorizontalAlignment(JTextField.CENTER);
  
               tf3.setText(rs.getString(3));
               tf3.setHorizontalAlignment(JTextField.CENTER);
  
               tf4.setText(rs.getString(4));
               tf4.setHorizontalAlignment(JTextField.CENTER);
  
               tf5.setText(rs.getString(5));
               tf5.setHorizontalAlignment(JTextField.CENTER);
  
               tf6.setText(rs.getString(6));
               tf6.setHorizontalAlignment(JTextField.CENTER);
  
               tf7.setText(rs.getString(7));
               tf7.setHorizontalAlignment(JTextField.CENTER);
  
               tf8.setText(rs.getString(8));
               tf8.setHorizontalAlignment(JTextField.CENTER);
  
               tf9.setText(rs.getString(9));
               tf9.setHorizontalAlignment(JTextField.CENTER);
  
               tf10.setText(rs.getString(10));
               tf10.setHorizontalAlignment(JTextField.CENTER);
  
               tf11.setText(rs.getString(11));
               tf11.setHorizontalAlignment(JTextField.CENTER);
  
               tf12.setText(rs.getString(12));
               tf12.setHorizontalAlignment(JTextField.CENTER);
  
               tf13.setText(rs.getString(13));
               tf13.setHorizontalAlignment(JTextField.CENTER);
  
               tf14.setText(rs.getString(14));
               tf14.setHorizontalAlignment(JTextField.CENTER);
  
               tf15.setText(rs.getString(15));
               tf15.setHorizontalAlignment(JTextField.CENTER);
  
  
  
               Blob blob = rs.getBlob(16);
               int blobLength = (int) blob.length();  
  
               byte[] bytes = blob.getBytes(1, blobLength);
              //blob.free();
               BufferedImage image = ImageIO.read(new ByteArrayInputStream(bytes));
  
  
               ImageIcon icon = new ImageIcon(bytes); // you can read straight from byte array
               l16 = new JLabel(icon);
               l16.setBounds(620, 350, 250, 250);
               add(l16);
  
  
  
               //add(frame_imagelabel);
                add(l1);
                add(tf1);
                add(l2);
                add(tf2);
                add(l3);
                add(tf3);
                add(l4);
                add(tf4);
                add(l5);
                add(tf5);
                add(l6);
                add(tf6);
                add(l7);
                add(tf7);
                add(l8);
                add(tf8);
                add(l9);
                add(tf9);
                add(l10);
                add(tf10);
                add(l11);
                add(tf11);
                add(l12);
                add(tf12);
                add(l13);
                add(tf13);
                add(l14);
                add(tf14);
                add(l15);
                add(tf15);
  
  
  
                add(frame_imagelabel);
                pack();
                setSize(1000,700);
  
  
          }
  
  
          //if(im!=null)
          //JOptionPane.showMessageDialog(null, "No image", "Warning", JOptionPane.ERROR_MESSAGE);
  
  
          if(count==0)
              JOptionPane.showMessageDialog(null, "This Student is not a member of this hall.", "Warning", JOptionPane.ERROR_MESSAGE);
  
  
          con.close();  
  
          } catch(Exception ex){ JOptionPane.showMessageDialog(null, ex, "Error", JOptionPane.ERROR_MESSAGE); }  
  
  
      }
  </code></pre>