Struts1 Action classes are not thread safe & instantiated only once.
So each request will access the same object.
Small Doubt -
If every request acess the same object.
What about the object inside the action classs, they will b instantiated per request or even they will behave same as Action class.
List lst = new ArrayList();
ArrayList object wil be instantiated per request ?
The code you have above has a variable in instance scope. There is one instance of that variable created for each instance of ActionClass, not for each request.
Have a look at the Action Class Design Guidelines