在存储它们之前，扩展Map <>，或者特别是HashMap <>来检查条目

I need a Map<> implementation that allows me to check values before they are stored in Map. The Map<> interface itself defines a lot of ways (methods) to put values in Map<>. In HashMap<> implementation all those 'ways' go through a single method putVal(...) and that's the perfect place to put my checking code. However, the method is declared as 'final', so I can't subclass from HashMap and override it.I need a Map<> implementation that allows me to