How do I identify immutable objects in Java

Question

In my code, I am creating a collection of objects which will be accessed by various threads in a fashion that is only safe if the objects are immutable. When an attempt is m

Answer 1

Like the other answerers already said, IMHO there is no reliable way to find out if an object is really immutable.

I would just introduce an interface "Immutable" to check against when appending. This works as a hint that only immutable objects should be inserted for whatever reason you're doing it.

interface Immutable {}

class MyImmutable implements Immutable{...}

public void add(Object o) {
  if (!(o instanceof Immutable) && !checkIsImmutableBasePrimitive(o))
    throw new IllegalArgumentException("o is not immutable!");
  ...
}