说明： Timer类
Java为程序代码的定时执行提供了方便的类。例如，如果编写一个时钟应用程序，希望他能够每秒钟更新一次显示，或者想在一些预定的时间播放一个报警声音 (Timer category Java code for the timing of the implementation of the convenience category. If, for example, the preparation of a clock application procedures in the hope that he can be updated every second, or to the predetermined time for a voice alarm)
