Java Tutorial/Collections/Wrapped Collections

Read-Only Collections

public static Collection unmodifiableCollection(Collection c)
public static List unmodifiableList(List l)
public static Map unmodifiableMap(Map m)
public static Set unmodifiableSet(Set s)
public static SortedMap unmodifiableSortedMap(SortedMap m)
public static SortedSet unmodifiableSortedSet(SortedSet s)

Exception in thread "main" java.lang.UnsupportedOperationException
  at java.util.Collections$UnmodifiableCollection.clear(Collections.java:1037)
  at MainClass.main(MainClass.java:20)