Problems with JList (multiple selection)

Question

hi!
i have a simple question.. why does this construct not work? i recieve a Casting Exception!
recList is a JList!
if(source == send){
     String[] rec = (String[])recList.getSelectedValues();
     String message = messageArea.getText();
thx,
chris

Answer 1

You can only cass an Object array to a String array if the array was created as a String array.
Object[] o = new String[] { "string1", "string2" };
String[] s = (String[])o; // this works fineIf it was created as an Object array, then you will get a ClassCastException:
Object[] o = new Object[] { "string1", "string2" };
String[] s = (String[])o; // throws ClassCastExceptionSo either you have to cast each Object element to a String, or copy all the elements to a String array like this:
Object[] o = new Object[] { "string1", "string2" };
String[] s = new String[o.length];
System.arraycopy(o, 0, s, 0, o.length); // or copy them in a for-loop which may be faster for small arraysReturning you an Object array that was created as an Object array is the easiest way for the JList to return you the selected values. So that's why you can't just cast it to a String array even though YOU know they are all String objects.