Refreshing GUI by another thread in java (swing)

Solution 1:

Here is a little snippet you can add to a method to ensure it executes in the the GUI thread. It relies on isEventDispatchThread().

public void updateGUI(final Status status) {
   if (!SwingUtilities.isEventDispatchThread()) {
     SwingUtilities.invokeLater(new Runnable() {
       @Override
       public void run() {
          updateGUI(status);
       }
     });
     return;
   }
   //Now edit your gui objects
   ...
}

Solution 2:

If you make the status field thread safe, then you can call setStatus directly from your background thread. To make the status thread-safe, put changes in a synchronize block, and make the variable volatile so updates on other threads become visible.

E.g.

public class Frame extends JFrame implements Runnable {
private volatile Status status = 1;
...
@Override
public void run() {
    switch (status) {
        case 1:
        ...
        case 2:
        ...
}

public void updateGUI(Status status) {
   setStatus(status);
   SwingUtilities.invokeLater(this);
}

private synchronized void setStatus(Status status) {
   this.status = status;
}

With these changes in place, it's ok to call setStatus from any thread.