A Java Interface does not extend the java.lang.Object class but instances of objects that implement the interface extend the Object class otherwise if Java Interfaces allowed to extend the java.lang.Object class then Java would support multiple inheritance of which it does not in its language specification.
Consider the scenario below:
interface MyInterface
{
// interface methods here
}
MyClass extend java.lang.Object implements MyInterface
{
// override methods or interface method implementations
}
Now if MyInterface extends java.lang.Object class then that would mean the MyClass would also be extending the MyInterface interface by construction creating multiple inheritance. So makes sense that Java interfaces do not extend the java.lang.Object class as this would create chaos due to multiple inheritance.