Solution : You have to set the initial value at static value. static으로 선언한 변수를 초기화 하지 않는 경우 발생합니다. Exception in thread "AWT-EventQueue-0" java.lang.NullPointerExceptionat javax.swing.plaf.basic.BasicTableUI.paintCell(Unknown Source)at javax.swing.plaf.basic.BasicTableUI.paintCells(Unknown Source)at javax.swing.plaf.basic.BasicTableUI.paint(Unknown Source)at javax.swing.plaf.ComponentUI.update(Un..