java.lang.ClassCastException

[anu johncy]

hi ,
i try to create simple login page using Eclipse Editor
the code is following :

EclipseClass.java

package eclipsepackage;

//import java.io.BufferedReader;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import javax.swing.*;
import javax.swing.event.AncestorListener;
 class  Login extends JFrame implements ActionListener
{
	 //final String  = null;
	JButton submit;
	JPanel panel;
	JLabel label1,label2;
	 JTextField text1,text2;
	Login()
	{
		System.out.println("inside login");
		label1=new JLabel();
		label1.setText("UserName");
		text1=new JTextField(15);
		
		label2=new JLabel();
		label2.setText("password");
		text2=new JPasswordField(15);
		
		submit =new JButton("submit");
		
		panel=new JPanel(new GridLayout(3, 1));
		panel.add(label1);
		panel.add(text1);
		panel.add(label2);
		panel.add(text2);
		panel.add(submit);
		add(panel,BorderLayout.CENTER);
		submit.addAncestorListener((AncestorListener) this);
		setTitle("Login form");
	
	}
	public void actionPerformed(ActionEvent ae)
	{
		String value1=text1.getText();
		String value2=text2.getText();
		if(value1.equals("admin")&& value2.equals("admin"))
		{
			NextPage page =new NextPage();
			page.setVisible(true);
			JLabel label =new JLabel("Welcome : "+ value1);
			page.getContentPane().add(label);
		}
		else 
		{
			System.out.print("Enter valid login:");
			JOptionPane.showMessageDialog(this,"Incorrectlogin","Error",JOptionPane.ERROR_MESSAGE);
			
			
		}
	}
}
public class Eclipseclass {

		
	public static void main(String[] args)   {
		

		System.out.println("Inside main class");

		try	{
			Login fame=new Login();
			System.out.println("fame");
			fame.setSize(300,100);
			fame.setVisible(true);
		}
		 catch(Exception e)
		{
			//JOptionPane.showMessageDialog(null,e.getMessage());
			System.out.println(e);
		}
		
		
	}

}

and one externel classfile having the same package that code is following :

NextPage.java

package eclipsepackage;

import javax.swing.JFrame;

 class NextPage extends JFrame
 {
	// System.out.println("Inside Nextpage class");
    NextPage()
    {
    	System.out.println("Inside Nextpage class");
	setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
	setTitle("Welcome");
	setSize(400,200);
}

}

then the error is
java.lang.ClassCastException: eclipsepackage.Login cannot be cast to javax.swing.event.AncestorListener

please support me to solve problem ,
thanks ,

[Edit - added code tags - MB]

[John Jai]

java.lang.ClassCastException: eclipsepackage.Login cannot be cast to javax.swing.event.AncestorListener 

The error occurs because the Login class cannot be cast to the mentioned one. Are you sure you want to add AncestorListener and not the ActionListener? Because the login class implements only the ActionListener.

[Matthew Brown]

And Welcome to The Ranch!