Login.java

@POST
@Consumes("application/x-www-form-urlencoded")
public Response login(@FormParam("login") String login, @FormParam("password") String password) {

    //If user already logged, then get it token 
    Optional<String> key = authSession.getToken(login, password);
    if (key.isPresent()) {

        return Response.ok(key.get()).build();

    }

    //Validate the login and password on data source    
    if (!authSession.getDataSource().containsKey(login)
            || !authSession.getDataSource()
                    .get(login)
                    .getPassword()
                    .equals(password)) {
        return Response.status(Response.Status.UNAUTHORIZED).build();
    }

    String token = TokenUtils.generateToken();
    //Persiste the information of authentication on the AuthSession.
    authSession.putAuthenticated(token, new Auth(login, password, new Date()));

    return Response.ok(token).status(Response.Status.CREATED).build();

}