Answer Posted / sivasubramanian.k

Session Tracking is one of the most powerful features of
Servlets and JSP. Basically, the servlet engine takes care
of using Cookies in the right way to preserve state across
successive requests by the same user. Your servlet just
needs to call a single method (getSession) and it has
access to a persistent hashtable of data that's unique to
the current user

public void doPost(HttpServletRequest request,
HttpServletResponse response){
...
//lets take the session obj
HttpSession session = request.getSession(true);
//now let us take the user name assosiated with this session
String currUserLogin = (String) session.getAttribute
("currentUserLogin")
...
//now we do the work according to the user name
doSomeWork(currUserLogin);
...

}

What is busy spin, and why should you use it?

1087

---

Does java list allow null?

997

---

What is a stringbuilder?

920

---

Class c implements interface I containing method m1 and m2 declarations. Class c has provided implementation for method m2. Can I create an object of class c?

1618

---

What are the differences between Java 1.0 and Java 2.0?

2280

---

Can a constructor be protected?

1090

---

Why do we need wrapper classes?

1072

---

What is java beans?

1004

---

Why we go for collections in java?

982

---

What is a function easy definition?

1013

---

What modifiers may be used with an inner class that is a member of an outer class in java programming?

1107

---

What is api data?

1007

---

What are implicit objects in java?

987

---

Why do we need data serialization?

998

---

Differentiate jar and war files?

1042

---