[JAVA] Need to add 'double' to hashtable - Tilted Forum Project Discussion Community

BoltedDown · 02-15-2005, 10:21 PM

Here is what i'm working with:

Code:

public class Menu1DB
{
    public static Hashtable loadMenu()
	{
        int i = 0;
	String line;
        Hashtable hshProdDesc = new Hashtable();
	Hashtable hshProdPrice = new Hashtable();
        StringTokenizer strings;
		try
		{
			BufferedReader file =
			new BufferedReader(new FileReader("menu.txt"));
			// priming read
			line = file.readLine();
			//while ((line = file.readLine()) != null)
			while (line != null)
			{
			strings = new StringTokenizer(line, ",");
			String strProdID = strings.nextToken();
			String strProdDesc = strings.nextToken();
			String strProdPrice = strings.nextToken();
			double dblProdPrice = Double.valueOf(strProdPrice).doubleValue();
			hshProdDesc.put(strProdID,strProdDesc);
//-->>	             hshProdPrice.put(strProdID,dblProdPrice);

Apparently '.put' only allows (Object, Object) so i'm stuck. I need to do (Object, double).

Thanks!

-BD

a-j · 02-15-2005, 11:35 PM

The Double class is derived from object, you need to use that since Java 1.4- doesn't support putting primitives inside hashtables. Something like

Code:

String strProdPrice = strings.nextToken();
Double dblProdPrice = Double.valueOf(strProdPrice);
hshProdDesc.put(strProdID,dblProdDesc);

madcow · 02-16-2005, 05:20 PM

a-j hit the nail on the head there. On a side note, it looks like you are adding both the product Id and the price under the same Hash table key. This won't work. Each item in a hash table needs to have a different key. Maybe you should make a "Product" class that holds all the information about a product (Description, Id and Price from what I can see) and store that in your Hash table.

02-15-2005, 11:35 PM	#2 (permalink)
a-j Tilted	The Double class is derived from object, you need to use that since Java 1.4- doesn't support putting primitives inside hashtables. Something like Code: String strProdPrice = strings.nextToken(); Double dblProdPrice = Double.valueOf(strProdPrice); hshProdDesc.put(strProdID,dblProdDesc);

02-16-2005, 05:20 PM	#3 (permalink)
madcow Crazy Location: The state of denial	a-j hit the nail on the head there. On a side note, it looks like you are adding both the product Id and the price under the same Hash table key. This won't work. Each item in a hash table needs to have a different key. Maybe you should make a "Product" class that holds all the information about a product (Description, Id and Price from what I can see) and store that in your Hash table. __________________ Smoke me a kipper, I'll be back for breakfast.