Hi,
I have implemented this function:
static <X,Y> Y castOrNull(X obj) {
try {
return (Y)obj;
}
catch(ClassCastException e) {
return null;
}
}
This gives me the compiler warning:
Type safety: Unchecked cast from X to Y
Which I don't exactly understand. Isn't the try/catch
which I am doing here a check for it? Can I ignore the warning?
Will my function work as expected or not? How would I implement it correctly?
I also tried with a obj instanceof Y
check but that doesn't work because of the way Java handle generics.
Btw., this function seems quite useful to me (to make some other code more clean). I wonder if such a function may already exist in Java?
One example where I want to use it:
void removeEmptyRawStrings() {
for(Iterator<Entity> e = entities.iterator(); e.hasNext();) {
RawString s = castOrNull(e.next());
if(s != null && s.content.isEmpty()) e.remove();
}
}
I have cases like these quite often in my code. And I think this is more readable and simpler than anything else. But please give me a better suggestion if you have any about how to make that code even more simple.