CODEWITHSUNDEEP
javainheritanceabstract-class
sadaf2605
sadaf2605

Reputation: 7540

Java abstract class extends two classes

I have got a similar line digging up a OpenSource Project: 

abstract class AbstractClass<A extends ParentClass1,
    B extends ParentClass2>

Can you please tell me what actually it means? I think java does not support multiple inheritance so what actually we are doing here? And what is A and B here? :S

Upvotes: 2

Views: 1906

Answers (3)

sanbhat
sanbhat

Reputation: 17622

If you remove the content within <>, then you see its only

abstract class AbstractClass

that means, the class is not extending any classes at all.

abstract class AbstractClass<A extends ParentClass1,
    B extends ParentClass2>

essentially means, the class would like to declare 2 generics A and B, and force its type. That means, it want the implementer of the class to supply the 2 classes which extends ParentClass1 and ParentClass2 respectively.

Please see this for more clarification

Upvotes: 0

unixxx
unixxx

Reputation: 73

it's generic type look here for generics: http://docs.oracle.com/javase/tutorial/java/generics/types.html

Upvotes: 0

Ankur Shanbhag
Ankur Shanbhag

Reputation: 7804

Here A and B are just place holders which can be replaced with any class that extends ParentClass1 and ParentClass2 respectively. You can pass arguments in angular brakets(<>) when you create object of this class. These arguments will be substituted for A and B by the compiler during compilation.

The above code does not indicate multiple inheritance. Please read generics in detail to understand this.

Upvotes: 2

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