Native Look and Feel with Java Swing
Java Swing applications look, well, Java swing like by default, which does not fit to the native look and feel of your OS.
For users this may feel out of place, uncommon, unintuitive and confusing.
Fortunately, it’s really easy to tell swing to use a native look and feel layout and design. Just use
javax.swing.UIManager.setLookAndFeel(javax.swing.UIManager.getSystemLookAndFeelClassName());