In Collection Framework, to make collection type object as unmodifiable java.Util.Collections class provides static methods to make these object as unmodifiable.
Collections Class Unmodifiable Methods
| static Collection unmodifiableCollection(Collection<? extends T> c) |
Returns an unmodifiable view of the specified collection. |
| static List unmodifiableList(List<? extends T> list) |
Returns an unmodifiable view of the specified list. |
| static <K,V> Map<K,V> unmodifiableMap(Map<? extends K,? extends V> m) |
Returns an unmodifiable view of the specified map. |
| static <K,V> NavigableMap<K,V> unmodifiableNavigableMap(NavigableMap<K,? extends V> m) |
Returns an unmodifiable view of the given map. |
| static NavigableSet unmodifiableNavigableSet(NavigableSet s) |
Returns an unmodifiable view of the given navigable set. |
| static Set unmodifiableSet(Set<? extends T> s) |
Returns an unmodifiable view of the given set. |
| static <K,V> SortedMap<K,V> unmodifiableSortedMap(SortedMap<K,? extends V> m) |
Returns an unmodifiable view of the given map. |
| static SortedSet unmodifiableSortedSet(SortedSet s) |
Returns an unmodifiable view of the given set. |
Example: Synchronized Collections
In this example creating the blank type of collection and making it Unmodified. You can assign the same with collection objects.
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
public class CollectionUnmodifiedExample {
public static void main(String[] args) {
Collection c = new ArrayList();
Collections.unmodifiableCollection(c);
Collections.unmodifiableList(new ArrayList());
Collections.unmodifiableMap(new HashMap());
Collections.unmodifiableSet(new HashSet());
}
}
Facing Issues On IT 