Cannot find symbol class (Java swing)

JanineXD

New Member

Join Date: Feb 2010
Posts: 18

Cannot find symbol class (Java swing)

Oct 17 '10, 06:44 AM

Hey,

I seem to have a problem on a Java Swing Program with ActionListener. I've tried to use getSource in our class but seem don't have an idea why it won't work when I tried to program at home. ( I'm using an earlier version of JCreator in school and a JCreator Pro here at home, Does that affect the program at all? )

Here's the code:

Code:

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Group2 extends JFrame implements ActionListener{

public void Group2(){
		JLabel text = new JLabel("Enter a number to partition: ");
        JTextField input = new JTextField(15);
 		JButton submit=new JButton("Submit");
		String listboxitems[]={"5","1111111","111111111","1111111111"};
		JList listbox = new JList(listboxitems);
		JLabel timeprocessed=new JLabel("It x milliseconds to process the output");
       	setSize(350, 250);
		setTitle("Group 2 COPRO2 & DATASTRUCT Project");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

  		FlowLayout layoutManager = new FlowLayout(FlowLayout.CENTER);
        layoutManager.setHgap(10);
        layoutManager.setVgap(10);
        setLayout(layoutManager);
        getContentPane().setComponentOrientation(ComponentOrientation.LEFT_TO_RIGHT);
		getContentPane().add(text);
		getContentPane().add(input);
		getContentPane().add(submit);
		getContentPane().add(listbox);
		getContentPane().add(timeprocessed);
        submit.addActionListener(this);
}
public void actionPerformed(ActionEvent ae){
if(ae.getSource()==submit){
		timeprocessed.setVisible(true);}
else{
System.out.println("error");
}
         }
        
    public static void main(String[] args) {
        new Group2().setVisible(true);
}
    

}

The error text:

Code:

C:\Documents and Settings\User\Desktop\Group2.java:31: cannot find symbol
symbol  : variable submit
location: class Group2
if(ae.getSource()==submit){
                   ^
C:\Documents and Settings\User\Desktop\Group2.java:32: cannot find symbol
symbol  : variable timeprocessed
location: class Group2
        timeprocessed.setVisible(true);}
        ^
2 errors

Thank You!

Tags: None

Nepomuk

Recognized Expert Specialist

Join Date: Aug 2007
Posts: 3111

Oct 19 '10, 01:56 PM

This looks like a scope problem. Try defining the Objects submit and timeprocessed outside of the constructor and just initializing them inside:

Code:

 //...

[b]private JButton submit;
private JLabel timeprocessed;[/b]

public class Group2 extends JFrame implements ActionListener{
 
public void Group2(){
        //...
        [b]submit=new JButton("Submit");[/b]
        String listboxitems[]={"5","1111111","111111111","1111111111"};
        JList listbox = new JList(listboxitems);
        [b]timeprocessed=new JLabel("It x milliseconds to process the output");[/b]
        //...
}
public void actionPerformed(ActionEvent ae){
if(ae.getSource()==submit){
        timeprocessed.setVisible(true);}
else{
System.out.println("error");
}
         }
    //...
}

Greetings,
Nepomuk

Cannot find symbol class (Java swing)

Cannot find symbol class (Java swing)

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