Collecting Objects - Beginning Java 7 - page 516

import java.util.TreeMap;

class NavigableMapDemo
{

public static void main(String[] args)
{

NavigableMap<String,Integer> nm = new TreeMap<>();
String[] birds = { "sparrow", "bluejay", "robin" };
int[] ints = { 83, 12, 19 };
for (int i = 0; i < birds.length; i++)
nm.put(birds[i], ints[i]);
System.out.println("Map = "+nm);
System.out.print("Ascending order of keys: ");
NavigableSet<String> ns = nm.navigableKeySet();
Iterator iter = ns.iterator();
while (iter.hasNext())
System.out.print(iter.next()+" ");
System.out.println();
System.out.print("Descending order of keys: ");
ns = nm.descendingKeySet();
iter = ns.iterator();
while (iter.hasNext())
System.out.print(iter.next()+" ");
System.out.println();
System.out.println("First entry =

"+nm.firstEntry());
System.out.println("Last entry = "+nm.lastEntry());
System.out.println("Entry < ostrich is

"+nm.lowerEntry("ostrich"));
System.out.println("Entry > crow is

"+nm.higherEntry("crow"));
System.out.println("Poll

first entry:

"+nm.pollFirstEntry());
System.out.println("Map = "+nm);
System.out.println("Poll last entry:

"+nm.pollLastEntry());