It appears that the Cursor class does not have a “blank” cursor to begin with, so one could define a new “blank” cursor using the Toolkit.createCustomCursor method.
Here’s one way I’ve tried which seems to work:
// Transparent 16 x 16 pixel cursor image.
BufferedImage cursorImg = new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB);
// Create a new blank cursor.
Cursor blankCursor = Toolkit.getDefaultToolkit().createCustomCursor(
cursorImg, new Point(0, 0), "blank cursor");
// Set the blank cursor to the JFrame.
mainJFrame.getContentPane().setCursor(blankCursor);
Edit
Regarding the comment about everything inside the JFrame ending up without a cursor, it seems that the Components which are contained in the JFrame will end up inheriting the cursor of the container (the JFrame), so if it is a requirement to have a certain Component have the cursor appear, one would have to manually set the desired cursor.
For example, if there is a JPanel contained in the JFrame, then one could set the cursor of that JPanel to the system’s default using the Cursor.getDefaultCursor method:
JPanel p = ...
// Sets the JPanel's cursor to the system default.
p.setCursor(Cursor.getDefaultCursor());