## String类

Stringequals

StringhashCode

## 泛型(Generic)重写equals()的问题

ConcreteEdgeGraph<L>的内部实现有一个Edge<L>类，我在重写equals遇到了问题。

Stackoverflow[4]上给出了建议的做法，这也是Eclipse提供的Quick fix：

Yes - this is a natural consequence of type erasure. If o is actually an instance of Action that won’t be caught by the cast - you’ll only see the problem when you try to use it, passing in a ClientInterface instead of a string.
You can get rid of the warning using:

as a function annotation, but you can’t easily sort out the underlying problem :（