没有从其他jsp上的会话获取哈希表值

Question

I am setting the value of a hash table in session

session.setAttribute("hash",chk); 
Hashtable<Integer,String> navchk = (Hashtable)session.getAttribute("hash");
Enumeration items = navchk.keys();
while(items.hasMoreElements())
{
    out.println(items.nextElement());
}
chk.clear();

at the particular page it is printing the values. here chk is hashtable.

on the other page when i am getting and printing values it is not working. Here is the code of second page....

Hashtable<Integer,String> chk1 = (Hashtable<Integer,String>)session.getAttribute("hash");

Enumeration items = chk1.keys();
while(items.hasMoreElements())
{
    out.println(items.nextElement());
}
chk1.clear();

Answer 1

Well for one thing, you are doing,

chk.clear();

in your first page. This will clear all your keys from that HashTable . Keep in mind what you are getting from session, is a reference to the object chk bounded to the key 'hash'. If you clear the keys from that object, you will not retrieve any keys in the second page.

Does that make sense ? :)