HashMap and For loop issue

[Mike Jenkins]

I have this JSP where I have alot of fields with conditions.
I would like to make it more efficient and use a for loop.
Here is an example (showing 2 fields for example only):

<%@ page language="java" import="java.util.*"  %>
<%
HashMap errors = new HashMap();
String firstname = "Joe";
String lastname = "Miller";
 
    if (!firstname.equals(""))
    {
        errors.put("firstname",firstname);
    }
    if (!lastname.equals(""))
    {
        errors.put("lastname",lastname);
    }
 
out.println(errors.get("firstname"));
out.println(errors.get("lastname"));
%>

It prints out Joe Miller

Now my attempt below to put this in a loop prints out null null:

<%@ page language="java" import="java.util.*"  %>
<%
HashMap errors = new HashMap();
String firstname = "Joe";
String lastname = "Miller";
//String[] keys = {"firstname", "lastname"};
String[] keys = {firstname, lastname};
for(int i = 0;i < keys.length;i++)
{
     if(!keys[i].equals(""))
    {
        errors.put(keys[i],keys[i]);
    }
}
 
out.println(errors.get("firstname"));
out.println(errors.get("lastname"));
 
%>

Please advise.

[Ben Souther]

 errors.put(keys[i],keys[i]);   

You're using the same string for the key and the value and neither of them is 'firstname' or 'lastname'.

In any event, this is not really a JSP specific issue.
This Java code in this scriptlet could be run from any Java program.
Moving to Java In General (Beginner)

[v ray]

yeah, what was said above is right.
Try this instead:

 
               for( int i = 0;i < keys.length;i++)
{
     if(!keys[i].equals(""))
    {
        errors.put(i,keys[i]);
    }
}

for(int i=0; i< keys.length; i++)
{
out.println(errors.get(i));

}

[ August 15, 2007: Message edited by: v ray ]