Given a scenario, write code that makes appropriate use of object locking to protect static or instance variables from c在给定的条件下,写出正确使用对象锁保护静态或实例变量不会产生并发访问问题的代码.
This access method is unusual in that it provides record level locking. This can provide beneficial performance improvem这种访问方式与众不同处在于他提供记录级别的锁.当程序需要并发的访问队列时,这一点可以提高性能.