泛型继承Comparable接口

This means that the type parameter must support comparison with other instances of its own type, via the Comparable interface.

( 这句话的大概意思就是你的泛型参数必须实现Comparable接口来达到自己的泛型实例之间能相互比较的目的。

An example of such a class is provided in the Oracle tutorial Object Ordering. Note the similar pattern to T extends Comparable<T> in the excerpt below:

public class Name implements Comparable<Name> {
   ...
   public int compareTo(Name n) { ... }
}