用java实现的UFO攻击游戏，里面有代码和可执行文件，操作简单，用鼠标左键单击UFO， 每击落10架之后，就会增加一架。-used to achieve the UFO attack game, and they code and executable files, simple operation, using the left mouse button click UFO, each downed 10, will be an increase.