How to store JavaScript variable value in JSP session [duplicate]

This question already has answers here: how to access the javascript variable in jsp [duplicate] 开发者_开发技巧 (3 answers) Closed 5 years ago.

I want to store a JavaScript variable value in JSP session to use it further in my Java classes methods. Please provide solution for storing any JavaScript variable in JSP session.

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Pass that variable to Servlet using ajax OR set it in some hidden field when form will get submit it will also get POSTed.

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Make an AJAX call from your JSP to a different JSP that does that. The jsp will take a variable name and its value as request parameters and will put the variable in the session.

You cannot do this with client side (javascript) code only !

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Your best bet is to just store the value in a cookie. Both client side javascript and server side jsp can access cookies.

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There should be a natural flow to your program, so that you don't have to have a mechanism specifically for storing variables just for the sake of storing variables. By that I mean that if you are storing a userName, it should be while login is occurring, or if you are obtaining contactInfo, then you should have a servlet specifically for that purpose. Regardless, here is a three part answer to your question. It is very general and non-specific, but will accomplish what you want once fleshed out:

Here is the web.xml file:

    <servlet>
        <servlet-name>StoreVariableServlet</servlet-name>
        <servlet-class>tests.servlets.StoreVariableServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>StoreVariableServlet</servlet-name>
        <url-pattern>/storeVariableServlet</url-pattern>
    </servlet-mapping>

Here is the jQuery Code:

    $.ajax({
        type: "POST",
        url: "/storeVariableServlet",
        data: ({
            variable : $(variableName).val()
        }),
        success: function(){
            alert("Success");
        }
    });

Here is the Servlet Code:

    String variableToBeStored = request.getParameter("variable");
    HttpSession session = request.getSession();
    session.setAttribute("variableXYZ", variableToBeStored);