java- generic class is a class or an interface in the end, why not use the wording implements ...

Original link: http://www.cnblogs.com/zhizhiyin/p/11114962.html

java-core P533

public static <T extands Comparable> T min(T[] a )

　　

Here had a question, is the generic class of English is the generic class, is not a class interface, but here with the extands Comparable, only the interface will extands interfaces, interfaces that generic class is it right?

P533 There are so many words and explained:

<T extands BoundingType> T should be represented by sub-type binding type (subType).
T may be a class type and binding, or may be an interface.
The reason for choosing keywords extands is closer to the concept of sub-class and java designer does not intend to add a new keyword (such as sub) in the language.

Therefore, with this generic <T extends Interface> extends in the meaning of the keyword is in fact defined a set of generic (bound) time, so that extends = extends or implements.

Reproduced in: https: //www.cnblogs.com/zhizhiyin/p/11114962.html