关于wait 和 notifyall的实用方法

Notifier is started ...Thread-2waiting ...Thread-3waiting ...Thread-4waiting ...notified all !!Thread-4doing !!!Thread-3doing !!!Thread-2doing !!!Thread-4doing !!!Thread-2doing !!!Thread-3doing !!!Thread-2doing !!!Thread-3doing !!!Thread-4doing !!!test  done !!!