spring - Is this method thread safe according to Java -

if 2 threads accessing method on server, thread safe? threads coming gwt timer.

public userdto getuserfromsession() {         userdto user = null;         httpservletrequest httpservletrequest = this.getthreadlocalrequest();         httpsession session = httpservletrequest.getsession();         object userobj = session.getattribute("user");         if (userobj != null && userobj instanceof userdto)         {             user = (userdto) userobj;         }         return user; } 

a method thread safe if doesn't access external (to method) shared variables.

the problem in code on line of code:

httpservletrequest httpservletrequest = this.getthreadlocalrequest(); 

because this.getthreadlocalrequest() seems access shared variable. sure post whole class, can see not thread safe.

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also after comment explain getthreadlocalrequest method returns httpservletrequest safely code remains not thread safe.

infact httpsession not thread safe according article: session can change during code execution. example can return user after invalidation of session. imagine steps:

thread 1                                                thread 2 ----------------------------------------------          -------------- object userobj = session.getattribute("user");                                                          session.invalidate();  if (userobj != null && userobj instanceof userdto) {     user = (userdto) userobj; } return user;     

at end return user if session invalidated thread.