//: containers/ReadOnly.java

package containers; /* Added by Eclipse.py */

// Using the Collections.unmodifiable methods.

import java.util.*;

import net.mindview.util.*;

import static net.mindview.util.Print.*;

public class ReadOnly {

static Collection<String> data =

new ArrayList<String>(Countries.names(6));

public static void main(String[] args) {

Collection<String> c =

Collections.unmodifiableCollection(

new ArrayList<String>(data));

print(c); // Reading is OK

//! c.add("one"); // Can't change it

List<String> a = Collections.unmodifiableList(

new ArrayList<String>(data));

ListIterator<String> lit = a.listIterator();

print(lit.next()); // Reading is OK

//! lit.add("one"); // Can't change it

Set<String> s = Collections.unmodifiableSet(

new HashSet<String>(data));

print(s); // Reading is OK

//! s.add("one"); // Can't change it

// For a SortedSet:

Set<String> ss = Collections.unmodifiableSortedSet(

new TreeSet<String>(data));

Map<String,String> m = Collections.unmodifiableMap(

new HashMap<String,String>(Countries.capitals(6)));

print(m); // Reading is OK

//! m.put("Ralph", "Howdy!");

// For a SortedMap:

Map<String,String> sm =

Collections.unmodifiableSortedMap(

new TreeMap<String,String>(Countries.capitals(6)));

}

} /* Output:

[ALGERIA, ANGOLA, BENIN, BOTSWANA, BULGARIA, BURKINA FASO]

ALGERIA

[BULGARIA, BURKINA FASO, BOTSWANA, BENIN, ANGOLA, ALGERIA]

{BULGARIA=Sofia, BURKINA FASO=Ouagadougou, BOTSWANA=Gaberone, BENIN=Porto-Novo, ANGOLA=Luanda, ALGERIA=Algiers}

*///:~