Generic array creation error
You can't have arrays of generic classes. Java simply doesn't support it.
You should consider using a collection instead of an array. For instance,
public static ArrayList<List<MyObject>> a = new ArrayList<List<MyObject>();
Another "workaround" is to create an auxilliary class like this
class MyObjectArrayList extends ArrayList<MyObject> { }
and then create an array of MyObjectArrayList
.
Here is a good article on why this is not allowed in the language. The article gives the following example of what could happen if it was allowed:
List<String>[] lsa = new List<String>[10]; // illegal
Object[] oa = lsa; // OK because List<String> is a subtype of Object
List<Integer> li = new ArrayList<Integer>();
li.add(new Integer(3));
oa[0] = li;
String s = lsa[0].get(0);
There is a easier way to create generic arrays than using List.
First, let
public static ArrayList<myObject>[] a = new ArrayList[2];
Then initialize
for(int i = 0; i < a.length; i++) {
a[i] = new ArrayList<myObject>();
}
You can do
public static ArrayList<myObject>[] a = (ArrayList<myObject>[])new ArrayList<?>[2];
or
public static ArrayList<myObject>[] a = (ArrayList<myObject>[])new ArrayList[2];
(The former is probably better.) Both will cause unchecked warnings, which you can pretty much ignore or suppress by using: @SuppressWarnings("unchecked")