Accessing label in another class?

Question

I'm trying to learn Java so sorry for the very simple question but I'm trying to change the text of a label in another class. I think I need to create a new instance of this label to access it from the second class but I just can't seem to get it to work. I don't know how to create the instance, which class to create the instance in why I want to create this instance and what this instance does really?
import java.awt.*;*
*import javax.swing.*;
import java.util.*;*
*import java.awt.event.*;
import java.lang.*;*
*public class StopWatch extends JFrame implements ActionListener*
*    private JButton button1 = new JButton("Start");*
*    private JButton button2 = new JButton("Stop");*
*    private JButton button3 = new JButton("Lap");*
*    private JButton button4 = new JButton("Clear");*
*    public JLabel label1 = new JLabel("The time goes here!!!!!!!!!!");*
*    public StopWatchConfig aConfig;*
*    public StopWatch(String input)*
*        button1.addActionListener(this);*
*        button2.addActionListener(this);*
*        button3.addActionListener(this);*
*        button4.addActionListener(this);*
*        displayGUI();*
*        aConfig = new StopWatchConfig();*
*    public void displayGUI()*
*        Container c = getContentPane();*
*        c.setLayout(new FlowLayout());*
*        //c.setBackground(Color.black);*       
*        c.add(button1);*
*        c.add(button2);*
*        c.add(button3);*
*        c.add(button4);*
*        c.add(label1);*
*        setSize(300,100);*
*        setVisible(true);*
*        public void actionPerformed(ActionEvent e)*
*            Object source = e.getSource();*
*            if ( e.getSource() == button1 )*
*                aConfig.start();*
*            if ( e.getSource() == button2 )*
*               aConfig.stopp();*
*            else if ( e.getSource() == button3 )*
*    //           timerSetup.lap();*
*            } // end if/else*
*            else if ( e.getSource() == button4 )*
*     //          timerSetup.clear();*
*            } // end if/else*
*    } // end method*
*import java.awt.*;
import javax.swing.*;*
*import java.util.*;
import java.awt.event.*;
import java.lang.System;
public class StopWatchConfig extends Thread
  public void start()
  public void stopp()
      aStopWatch.label1.setText("CHANGED!");
  public void lap()
  public void clear()
}

Answer 1

You don't want a new instance -- that would be an entirely different label, and not have any effect on what you're doing. What you want is a reference to the object you're changing.
What I would suggest is that you make sure only StopWatch can change its own label, say, with a method setTime(). Then, any other object that has a reference to that instance of StopWatch can call that method, and StopWatch will control the changing of its own components.
However, you're dealing with multithreading issues here, too, which is another beast. When you have two threads talking to each other you've got some things you need to take into account, such as synchronization. I'd say try to get this to work within a single thread first -- maybe have a button inside StopWatch that sets its own time.