How to clear Jlabel ?

[reon]

Hi

in this code when i clicked login button...it shows output as login...
But when i clicked each time its repeating .. i want to see that only ones ...
I want to clear the previous login before i clicked...

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
class LabelClear
{
static JLabel label,clear;
static JFrame frame;
static JButton login;
static JPanel panel;
 
public static void main(String args[])
    {
    frame = new JFrame();
 
    login = new JButton("Login");
 
    panel = new JPanel();
    //panel.add(label);
    panel.add(login);    
 
 
    frame.getContentPane().add(panel);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(3);
    frame.setSize(300,200);    
 
    Listener obj = new Listener();
    login.addActionListener(obj);
    }
static class Listener implements ActionListener
    {
    public void actionPerformed(ActionEvent evt)
        {
        Object obj = evt.getSource();
        if(obj == login)
            {
            label = new JLabel("Login");
            clear = new JLabel(" ");
            panel.add(clear);
            panel.revalidate();
            panel.add(label);
            panel.revalidate();
            }
        }
    }
}
 

[r035198x]

Hi

in this code when i clicked login button...it shows output as login...
But when i clicked each time its repeating .. i want to see that only ones ...
I want to clear the previous login before i clicked...

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
class LabelClear
{
static JLabel label,clear;
static JFrame frame;
static JButton login;
static JPanel panel;
 
public static void main(String args[])
    {
    frame = new JFrame();
 
    login = new JButton("Login");
 
    panel = new JPanel();
    //panel.add(label);
    panel.add(login);    
 
 
    frame.getContentPane().add(panel);
    frame.setVisible(true);
    frame.setDefaultCloseOperation(3);
    frame.setSize(300,200);    
 
    Listener obj = new Listener();
    login.addActionListener(obj);
    }
static class Listener implements ActionListener
    {
    public void actionPerformed(ActionEvent evt)
        {
        Object obj = evt.getSource();
        if(obj == login)
            {
            label = new JLabel("Login");
            clear = new JLabel(" ");
            panel.add(clear);
            panel.revalidate();
            panel.add(label);
            panel.revalidate();
            }
        }
    }
}
 

1.)What is the use of the label called clear in your code?
2.)label.setText(""); clears the value of a label to the empty string.

[Ekta Goel]

panel.add(clear) will create another label with its text as "".
SO, you must setText the previous label as"".
If you get problem in showing number of JLabels on refreshing the screen , then you must use panel.removeAllChildComponents().