java ee check if session exists or is new

To check if a session exists or is new in Java Enterprise Edition (Java EE), you can use the getId() method of the HttpSession interface.

Here's an example of how to check if a session exists or is new in a Java EE application:

import javax.servlet.http.*;

public class SessionChecker extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) {
        // Get the session
        HttpSession session = request.getSession(false);

        // Check if the session is new
        if (session == null || session.isNew()) {
            // The session is new
            System.out.println("New session");
        } else {
            // The session exists
            System.out.println("Existing session");
        }
    }
}

In this example, the doGet() method of the HttpServlet gets the current session using the getSession(false) method. This method returns the current session if it exists, or null if it does not exist.

The isNew() method of the HttpSession interface returns true if the session is new, and false if it is not.

You can use these methods to determine whether a session exists or is new in a Java EE application.