public class Test {
public static void main(String[] args) {
doOp(OpConstants.TURN_RIGHT);
}
public static void doOp(OpConstants opConstant) {
switch(opConstant) {
case TURN_LEFT:
System.out.println("向左转");
break;
case TURN_RIGHT:
System.out.println("向右转");
break;
case SHOOT:
System.out.println("射击");
break;
}
}
}
运行出现以下错误:

代码出自:http://caterpillar.onlyfun.net/Gossip/JavaGossip-V1/EnumeratedTypes.htm,向各位请教,该怎样修改才能编译成功。