Iterate through HashMap?

I have a HashMap with some elements. Now I would like to generate a String that contains each key and its correpsponding value for all the tuples in the HashMap.

I have tried:

HashMap hm =new HashMap();

hm.put("5","read");

hm.put("6","crap");

hm.put("7","bob");

Set s = hm.entrySet();

Iterator ni = s.iterator();

String ss ="";

while (ni.hasNext())

{

ss =ss + ni.next();

}

System.out.println(ss);

but that gives me:

5=read7=bob6=****

why do I get the equal signs?

[863 byte] By [lokpesta] at [2007-10-3 4:58:28]