I'm very new to Lambda, and I would like to have a Generic class done so like a non-generic class. Take for example the Runnable, it isn't generic:
Runnable runnable = () -> {
// code here
}
And I had a Generic class, how would I do it in Lambda just like I can with a non-generic class?
MyGenericClass<T> generic = ...
Lambdas use generics and type inference heavily. So much so that type inference was add to Java 8 to make the syntax more readable.
Let me give you an example
// this adds a dynamic reference to this method
Predicate<String> isEmpty = String::isEmpty;
or
// this creates a new lambda static method and
// creates a dynamic reference to that method
Predicate<String> isEmpty = s -> s.isEmpty();
or
Predicate<String> containsX = s -> s.contains("X");
These are used by Stream.filter()
There's an example here where they use:
Callable<String> c = () -> "Hello from Callable";
and
List<Employee> list = new ArrayList<Employee>();
Collections.sort(list,
(x, y) -> x.getLastName().compareTo(y.getLastName()));
Is that what you are looking for?
Essentially - the lambdas in java 8 take the type intuition that was introduced in Java 7 to the nth degree. It is really quite astonishing how effective it is in working out the types of complex expressions.
Runnableis not genericFunctionalInterface(though the annotation itself is not mandatory). See Function<> or Predicate<> for examples of easy-to-understand generic functional interfaces.Runnabledoesn't have any type parameters. What are you trying to achieve? You may need to useCallable.