What is "jinternalframe"

Usually, you add JInternalFrames to a jdesktoppane. The user interface delegates the specific actions of the look-and-Feel for an object Desktopmanager maintained by JDesktopPane.

You add child components from JInternalFrame in his ContentPane . As a convenience, the methods add(), remove() and setLayout() of this class are replaced, so that they delegate calls to the corresponding methods of the ContentPane.

For example, you can add a child component to an internal frame as follows:

internalFrame.add(child);

And the child component will be added to the ContentPane.

To learn more about this component and examples of use, see How to Use Internal Frames.