Authenticating from a JIRA plugin

[Subhajit Bhuiya]

I have written a JIRA plugin where I am getting accepting user id and password. Using those information, I want to authenticate or logged into JIRA and want subsequent  call in the same session to use the user. I am trying to use

String userId = req.getParameter("username");
String password = req.getParameter("password");
boolean authenticate = userManager.authenticate(userId, password);
if(authenticate){
UserProfile profile = userManager.getUserProfile(userId);
ApplicationUser applicationUser = ApplicationUsers.byKey(profile.getUserKey().toString());
authContext.setLoggedInUser(applicationUser);
applicationUser = authContext.getLoggedInUser();
}else{
resp.setStatus(500);
}

Is there any alternative to do login? This seems to be not working. Subsequent requests are not finding login user