JSP giving an exception error

Question

I am trying to run my JSP but its giving a null pointer exception. Following is the part of my JSP page:
String subject = (String) session.getValue("mess_subject");
Vector senderS = db.getSendS(subject); //calling the getSendS method from the bean
getSendS method (in the bean) returns a Vector which contains the stuff returned from the query. THe method is as follows:
public Vector getSendS(String message_subject)
{ResultSet rs;
   Statement stmt;
  // String Mess_subject;
   int i=0;
   String queryText2= "select Send_Name from MainTable2 where Mess_Subject=message_subject AND Reply='no'";
   Vector get_Sender=null; 
try
      stmt=con.createStatement();
      rs=stmt.executeQuery(queryText2);
      get_Sender= new Vector();
while(rs.next())
get_Sender.addElement(rs.getString(1));          
}//while loop          
return get_Sender;     
}//try     
catch(SQLException e)
{          e.printStackTrace();          
return null;     
}//catch
}//getText
Please help me understand whats going wrong. Thanks!

Answer 1

Rambee.. i'm not really sure what you were trying to accomplish by your changes, but it's entirely possible you see something I don't. However, if nothing was returned from the db, then the resultset would be empty, and the while loop would terminate before the first run. Which is essentially exactly what you did with your if-do-while construction, which just seems a bit contrived.
What could be happening, however, is that the rs.getString(1) is returning null. If so, then you are trying to assign a null value as an element into a Vector. Try running some tests there and see what you can come up with.