JFrame JDialog透明

        JFrame.setDefaultLookAndFeelDecorated(true
);
        SwingUtilities.invokeLater(new
 Runnable() {
            public
 
void
 run() {
                Window w = new
 TranslucentWindow();
                w.setVisible(true
);

        //要使窗口透明，您可以使用 AWTUtilities.setWindowOpacity(Window, float) 方法
                com.sun.awt.AWTUtilities.setWindowOpacity(w, 0
.5f);
            }
         });