How to: What is the reason why “synchronized” is not allowed in Java 8 int erface methods?

What is the reason why “synchronized” is not allowed in Java 8 interface methods?

In Java 8, I can easily write:

interface Interface1 { default void method1() { synchronized (this) { // Something } } static void method2() { synchronized (Interface1.class) { // Something } } }

I will get the full synchronisation semantics that I can use also in classes. I cannot, however, use the synchronizedmod…

How to: Why is "final" not allowed in Java 8 interface methods?

Why is "final" not allowed in Java 8 interface methods?

One of the most useful features of Java 8 are the new default methods on interfaces. There are essentially two reasons (there may be others) why they have been introduced:

Providing actual default implementations. Example: Iterator.remove()

Allowing for JDK API evolution. Example: Iterable.forEach()

From an API designer’s perspective, I…