Have you ever found the need to maintain a structured list of items? Of course! Have you ever needed to make sure those items stay in natural order? Maybe. If you answered yes then you need the Java TreeMap class.

Let us say we are going to store a structure of employee names and their titles associated to them. In this example we will keep just such a list, insert them in random order, and you will see the output result comes out in alphabetical (natural) order. The order is maintained based on the KEY, by the way. So, without further ado, here is an example.

<cfscript>
	treeMap = createObject("java", "java.util.TreeMap").init();

	writeOutput("Inserting the following employees in this order: Donny, Adam, Kujo, Johnny.");

	treeMap.put("Donny", "President");
	treeMap.put("Adam", "Engineer");
	treeMap.put("Kujo", "Director");
	treeMap.put("Johnny", "Support");

	writeOutput("Now show the contents of this tree in key order.");

	iter = treeMap.keySet().iterator();
	while (iter.hasNext()) {
		key = iter.next();
		writeOutput("Key: #key# Value: #treeMap.get(key)#");
	}
</cfscript>

In this example we instantiate the TreeMap class first. We then insert the employees Donny, Adam, Kujo, and Johnny, making the value of these keys their job titles. We then get an iterator for the keyset (an array of the TreeMap keys) and loop while we still have keys, displaying the key name, and its value. Here is what the output looks like.

> Inserting the following employees in this order: Donny, Adam, Kujo, Johnny.
>
> Now show the contents of this tree in key order.
> Key: Adam Value: Engineer
> Key: Donny Value: President
> Key: Johnny Value: Support
> Key: Kujo Value: Director