**
 * 原理就是当Iframe不是焦点时，<br>
 * 使用setVisible(true)对他再次显示<br>
 * 就会有闪烁效果
 * @author 飞雪无情
 *
 */
public class JFrameTest {
    private JFrame frame = null; 
    public JFrameTest() { 
        frame = new JFrame("Test");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 300);
        frame.setVisible(true);
        try { 
            // 这里等待3秒钟，你打开其程序，
            //主要目的是使frame不是当前的聚焦窗体
            Thread.sleep(3000);
        }catch (InterruptedException e1){ 
            e1.printStackTrace();
        } 
        frame.setVisible(true);
    }
    /**
     * @param args
     */
    public static void main(String[] args) {
        new JFrameTest();
    }

}

------解决方案--------------------
Java code

    /**
     * Flashes the specified window. It does not change the active state of the
     * window.
     * 
     * @param hwnd
     *            specified window handle.
     * @param flash
     *            whether flash the window.
     * @return return true if do the operation successfully, else return false.
     * 
     */
    public static boolean flashWindow( int hwnd, boolean flash )
    {
        FLASHWINFO flashInfo = new FLASHWINFO( );
        if ( flash )
            flashInfo.dwFlags = FLASHWINFO.FLASHW_ALL | FLASHWINFO.FLASHW_TIMER;
        flashInfo.hwnd = hwnd;
        return Extension.FlashWindowEx( flashInfo );
    }