code for The NavigableMap Interface

The java.util.NavigableMap interface, a new addition to Java 6, inherits SortedMap to add navigation methods that allows for key/value pair searching.

The java.util.TreeMap class in Java 6 implements NavigableMap.

import java.util.NavigableMap;
import java.util.TreeMap;
import java.util.Map.Entry;

public class NavigableMapDemo {
public static void main(String[] args) {
NavigableMap map = new TreeMap();
map.put(2, "two");
map.put(1, "one");
map.put(3, "three");
System.out.println("Original map: " + map + "\n");

Entry firstEntry = map.pollFirstEntry();
System.out.println("First entry: " + firstEntry);
System.out.println("After polling the first entry: " + map + "\n");

Entry lastEntry = map.pollLastEntry();
System.out.println("Last entry:" + lastEntry);
System.out.println("After polling last entry:" + map);
}
}

/*Original map: {1=one, 2=two, 3=three}

First entry: 1=one
After polling the first entry: {2=two, 3=three}

Last entry:3=three
After polling last entry:{2=two}
*/