线程问题，运行时候泡这个异常！
Exception in thread "AWT-EventQueue-0" java.lang.IllegalThreadStateException
at java.lang.Thread.start(Unknown Source)
at PlayUI.LyricsDisplay(PlayUI.java:509)
at PlayUI.playSong(PlayUI.java:868)
at PlayUI.playState(PlayUI.java:836)
at PlayUI$2.mouseClicked(PlayUI.java:287)
at java.awt.Component.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.List.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
[解决办法]
给你个建议吧
1 你的线程有结束条件吗？设置停止标志。
2 2个线程有冲突，你应该等第一个线程结束，再启动第二个线程
3 java的 Thread.stop 方法可以强行干掉线程，但不推荐。
