Displaying console output in jtextarea even when other actions occur

Displaying console output in jtextarea even when other actions occur

I found this code here: how to display console output in java JTextarea
one by one in a loop when button action is triggered and it displays
console output in a jtextarea. I have added this class as action in a
jmenuitem. So that it appears when I want and when I run other classes it
will show the output there. However when I launch it, it works properly,
but if I try and launch another class which will show output in console
and accept userinput, the jtextarea which is supposed to show console
output at the same time, it freezes. How could I make it so that it stays
tuned, despite invoking other classes/frames? Thanks in advance
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class DynamicWrite implements ActionListener
{
JFrame frame = new JFrame("TextArea");
JTextArea tArea = new JTextArea(10,20);
JButton button = new JButton("Click");
JScrollPane pane = new JScrollPane(tArea);
SwingWorker worker;
String s= "Java is an Object Oriented Programming langauge...Java is
static typed language...asbfldfjsdj";//some random String
public void prepareAndShowGUI()
{
Container container = frame.getContentPane();
container.add(pane);container.add(button,BorderLayout.NORTH);
tArea.setLineWrap(true);
tArea.setWrapStyleWord(true) ;
button.addActionListener(this);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent evt)
{
if(evt.getSource()==button)
{
tArea.setText("");
if (worker!=null)
{
worker.cancel(true);
}
worker = new SwingWorker()
{
@Override
protected Integer doInBackground()//Perform the required
GUI update here.
{
try
{
for(int i = 0;i<s.length();i++)
{
tArea.append(String.valueOf(s.charAt(i)));
Thread.sleep(5);
}
}catch(Exception ex){}
return 0;
}
};
worker.execute();//Schedules this SwingWorker for execution on
a worker thread.
}
}
public static void main(String st[])
{
DynamicWrite dyna = new DynamicWrite();
dyna.prepareAndShowGUI();
}
}