session-variables

Check if PHP session has already started

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I have a PHP file that is sometimes called from a page that has started a session and sometimes from a page that doesn’t have session started. Therefore when I have session_start() on this script I sometimes get the error message for “session already started”. For that I’ve put these lines: if(!isset($_COOKIE[“PHPSESSID”])) { session_start(); } … Read more

How do servlets work? Instantiation, sessions, shared variables and multithreading

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Suppose, I have a webserver which holds numerous servlets. For information passing among those servlets I am setting session and instance variables. Now, if 2 or more users send request to this server then what happens to the session variables? Will they all be common for all the users or they will be different for … Read more