package chapter17.four; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.List; public class Unsupported { static void test(String msg,List list){ System.out.println("------"+msg+"------------"); Collection c=list; Collection subList=list.subList(1, 4); //copy of subList Collection c2=new ArrayList(subList); try { c.retainAll(c2); } catch (Exception e) { // TODO: handle exception System.out.println("retainAll"+e); } try { c.removeAll(c2); } catch (Exception e) { // TODO: handle exception System.out.println("removeALL"+e); } } public static void main(String[] args) { List list=Arrays.asList("A B C D E F G H I J K L M ".split(" ")); test("Modifiable", new ArrayList(list)); test("Arrays.asList()",list); test("unmodifiableList()",Collections.unmodifiableList(new ArrayList(list))); } }