JLabel text disappears after less than a second

Question

I made a JFrame in netbeans ( it currently contains only one JLabel) which connects to the database and gets a field and display it in the JLabel. when I run the program, the JLabel displays the field for less then a second, then the text in the JLabel disappears !! Can anyone tell me why is this happening ? I also tried it in a JTextField, also same problem.

code :

public class frame extends javax.swing.JFrame {

    public frame() {
        initComponents();
    }

public void doingAll() {

      StringBuffer message = new StringBuffer();
    try {
      Statement stmt;
      Class.forName("com.mysql.jdbc.Driver");
      String url ="jdbc:mysql://localhost:3306/Junk2";
      Connection con = DriverManager.getConnection( url,"root", "");
      System.out.println("URL: " + url);
      System.out.println("Connection: " + con);
      stmt = con.createStatement();

      stmt.executeQuery("select * from Junk2.example");
      ResultSet rs = stmt.executeQuery("select * from Junk2.example");
      int columns = rs.getMetaData().getColumnCount();
      while(rs.next()){
      for (int i=1;i<=columns;i++){
      message.append(rs.getString(i)+" ");
      }
      message.append("\n");
      }
      System.out.println(message);

      con.close();
      }catch( Exception e ) {
      e.printStackTrace();
      }//end catch
      jLabel1.setText(message.toString());
      jTextField1.setText(message.toString()); 


       java.awt.EventQueue.invokeLater(new Runnable(){public void run(){new frame().setVisible(true);}});

    }

    // Variables declaration - do not modify
    private javax.swing.JLabel jLabel1;
    private javax.swing.JTextField jTextField1;
    // End of variables declaration

}

Answer 1

I am guessing that somewhere else in your code, you are clearing the field.

Search through your code for places where

• you do setText("");
• remove the label from the screen
• draw another component over the top of the label
• have implemented your own draw method.

Alternatively, post you code here. Your question is far to vague to give a clear definite answer.

edit: following your code show

Your doingAll method is not static, which means you will have to have created a frame object to call it. Then, at the end of that method, you are creating a new frame with the code

java.awt.EventQueue.invokeLater(new Runnable(){public void run(){new frame().setVisible(true);}});

This doesn't make sense. There is more going on here, as this is not all your code, but I guess the above line of code is the starting point for some (if not all) of your problems.