Java: Calling static method but nothing happens?

Question

I have a class called GUI which basically creates a latout using Swing. In that class i have a method called "log" which is supposed to add a new line to a textarea in the layout.

The problem is that whenever i call the function from outside of the GUI class, nothing happens. If i call the method from within the class it adds a line to the textarea as it's supposed to do.

I have set the method and all the variables it calls to public static, and i don't get any errors. It just doesn't do anything when i call the method from the outside.

Any ideas?

Edit:

Here's the method within the GUI class:

public static void log(String inputString) {
    logConsole.append(inputString + "\r\n");
}

At the bottom of the class swing declared the textarea, and i just modified it to be public static instead of private.

public static javax.swing.JTextArea logConsole;

Can't post more code, hope this is at least a little bit helpful? :/

Answer 1

It's most likely a concurrency issue with Swing. Since Swing is single-threaded, Swing components need to be modified in the Event Dispatch Thread (ie EDT). For more information, see Concurrency in Swing .

---

EDIT -

If this is indeed a concurrency issue, then one quick workaround would be to use SwingUtilities . In particular, isEventDispatchThread() and invokeLater(...) . For instance,

if(!SwingUtilities.isEventDispatchThread()){
    SwingUtilities.invokeLater(new Runnable(){
        @Override
        public void run(){
            GUI.log("foo"); // modify textarea in EDT
        }
    });
}
else{
    // your problem lies elsewhere
}