View Compilation Error

0_0_16080560_16534.c:1:1: error: unknown type name 'public'
 public class JComboBoxDemo extends JFrame implements ItemListener
 ^
0_0_16080560_16534.c:1:14: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'JComboBoxDemo'
 public class JComboBoxDemo extends JFrame implements ItemListener
              ^
0_0_16080560_16534.c:1:14: error: unknown type name 'JComboBoxDemo'