Java tutorial
//package com.java2s; import java.awt.Component; import javax.swing.SwingUtilities; public class Main { /** * Requesting focus in a Window should always be done last, after repainting etc. * This method calls {@link Component#requestFocusInWindow()} via "invokeLater" * which should make it the last UI action to perform and make it more likely * that the focus request works. * <br>See also {@link #requestFocusSelectAll(JTextField)}. */ public static void requestFocus(final Component c) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { c.requestFocusInWindow(); } }); } }