How Java 8 has concrete methods in Collection Interface?

Asked Nov 14 '18 at 08:14

Active Nov 14 '18 at 08:25

Viewed 472 times

I was referring to the Collection Interface of Java 8, where I saw that Collection method has concrete method public boolean removeIf(Predicate paramPredicate) , but as per the definition of Interface we can only have static and default method with body and rest can be abstract. I tried creating the concrete method in an Interface and received compile time error Abstract methods do not specify a body with 3 quick fixes from eclipse:

Change method to default
Change method to static
Remove method body

Can anyone explain how Collection interface has concrete implementation of methods removeIf , spliterator , stream , parallelStream ?

edited Nov 14 '18 at 08:25

asked Nov 14 '18 at 08:14

Prakash Vk

2

It's a `default` method : `default boolean removeIf(Predicate super E> filter)` – Eran Nov 14 '18 at 08:16
Default Methods in interfaces is a new feature of Java 8... – Guillaume Barré Nov 14 '18 at 08:16
4

@Nirekin that "new" feature will turn 5 years very soon – Eugene Nov 14 '18 at 08:17
2

@Eugene ... and Java 8 itself is end of public updates in Jan '19. ;) – Peter Lawrey Nov 14 '18 at 08:18
My decompiler is showing it as public, got it verified from official site https://docs.oracle.com/javase/8/docs/api/java/util/Collection.html it is default method. :p – Prakash Vk Nov 14 '18 at 08:30

How Java 8 has concrete methods in Collection Interface?

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