Catching ArrayStoreException at Compile-time

Question

Consider the following test of Java\'s ArrayList#toArray method. Note that I borrowed the code from this helpful answer.

public class GenericTest {
         


        

Answer 1

List#toArray(T[]) is a generic method declared as

 T[] toArray(T[] a);

So the type argument is either inferred from the type of the given array or with the notation prefixing the method invocation.

So you could do

String[] baz = foo.toArray(new String[10]); // doesn't compile

But I think that's the best you could do.

But in that sense, you can clearly see that Integer doesn't match String (or vice-versa).

Note that this is a documented exception

ArrayStoreException - if the runtime type of the specified array is not a supertype of the runtime type of every element in this list

So I don't think you should be trying to find it at compile time.