The SortedMap Interface

This section contains the detail about the SortedMap Interface in java.

The SortedMap Interface

The SortedMap Interface extends Maps. It maintains the elements in increasing order of key value.

Exception thrown by the methods :

Several methods throw a 'NoSuchElementException' when no items are in the invoking map. A 'ClassCastException' is thrown when an object is incompatible with the elements in a map. A 'NullPointerException' is thrown if an attempt is made to use a null object when null is not allowed in the map.

The methods of SortedMap are given below :

Example :

The 'Map.Entry' interface enables you to work with a map entry. The 'entrySet( )' method declared by the Map interface returns a Set containing the map entries. Each of these set elements is a 'Map.Entry' object.

import java.util.*;

public class SortedMapDemo {
	
public static void main(String args[]) {
	// Create a hash map
	TreeMap tm = new TreeMap();
	// Put elements to the map
	tm.put("Nicole", new Double(3434.34));
	tm.put("Ketty", new Double(123.22));
	tm.put("Linsay", new Double(1378.00));
	tm.put("Jay Sean", new Double(99.22));
	tm.put("Sakira", new Double(-19.08));
	
	// Get a set of the entries
	Set set = tm.entrySet();
	// Get an iterator
	Iterator i = set.iterator();
	// Display elements
	while (i.hasNext()) {
		Map.Entry me = (Map.Entry) i.next();
		System.out.print(me.getKey() + ": ");
		System.out.println(me.getValue());
	}
	System.out.println();
	// Deposit 1000 into Nicole's account
	double balance = ((Double) tm.get("Nicole")).doubleValue();
	tm.put("Nicole", new Double(balance + 1000));
	System.out.println("Nicole's new balance: " + tm.get("Nicole"));
}

}

Output :

Download Source Code