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Hashtable's java. lang. NullPointerException

 
Greenhorn
Posts: 24
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this is my code,a shopcart bean example;
import java.util.*;
public class shopCart
{
private Hashtable hashCart;
public void shopCart()
{
try
{
hashCart = new Hashtable();
System.out.println("initializing....");
}
catch(Exception ex)
{
System.out.println(ex.toString());
}
}
public void insCartItem(String merchNo,int merchNum)//
{
System.out.println("yaya");
try
{
hashCart.put("merchNo"+merchNo,merchNo);
hashCart.put("merchNum"+merchNo,new Integer(merchNum));
}
catch(Exception ex)
{
System.out.println(ex.toString());
}
}
}
i use this bean in a jsp file.
Hashtable shopBean=new shopCart();
shopBean.insCartItem("12345678",2)
then show me the Exception --java.lang.NullPointerException
 
Greenhorn
Posts: 20
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In jsp using usebean u create instance of shopcart
<jsp:useBean id = "shopBean" class="shopCart" />
then use like this
shopBean.insCartItem("12345678",2);
 
Rancher
Posts: 13459
Android Eclipse IDE Ubuntu
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Please don't post the same question in multiple forums, we just end up having the same conversation multiple times.
This question is covered in the JiG (intermediate) Forum here
Dave
 
Ranch Hand
Posts: 1873
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hi
read my reply at the original post page...
here
-maulin
 
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