First I want to say what I know about javadoc java.lang.Object.hashCode(), and therefore there is no need to mention it again.
I ask: Why didn’t I java.lang.Object.hashCode()move to a separate interface with the name (possibly) Hashable? How is `java.lang.Comparator '?
For me it is hashCode()used only in hash-dependent data structures, such as HashMapor HashTable, which are not used in every application b) are often used with very few types of keys, such as Stringor Integer, and not with InputStream(or something like this).
I know that I do not need to implement hashCode()for each of my classes, however, does not add a method to the class due to performance to some extent? Especially for java.lang.Object- the superclass of every class in Java.
Even if special optimization is performed in the JVM, so that performance loss can be ignored, I still find it unwise to provide everyone with Objectbehavior that is not often implemented at all. In accordance with the principle of separation of circuits :
No client should depend on methods that it does not use.
I have done several searches on the Internet, and the only related page I could find is this .
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