How to use JSTL within JSP declaration

Question

I want to use JSTL within JSP declaration. I have code like:

<%! void fetchData(String .., String ..){
    //some code...
    pageContext.setAttribute("test",valueForJSTL); // Wont work until I pass pageContext from calling scriptlet
    //some code...
%><%
    //use pageContext variable set above to user in JSP (c:out, wcf:getData etc)**
%><%
}%>

I wonder why is it not allowed to used scriptlet (line 5-7) within JSP declaration. Or is there any other way to handle this?

I am calling above function from a scriptlet and I want this method to do some manipulation, add a variable in pageContext/request and fetch the variable in JSTL to fetch the data from DB .

You can find complete file at: http://wikisend.com/download/738986/MyView.jsp The JSTL within declaration "fetchCatalogEntries" is not working.

Answer 1

This is because the generated code for the scriptlet <% %>goes in the service method which is like called again and over the same object using multiple request threads

Whereas <%!, goes into the global class space or simply to declare methods and variables global for a JSP page.

Hence in your scriptlet you can call the method say fetchData() or any other like you would inside a service() method like in a normal java class.

You can even declare a field as below and refer it as in the example below :

<%!
    private final Logger logger = new Logger(this.getClass());
    private UserService userService = null;
    public void jspInit() {
        userService = new UserService();
    }
    private String getUserStatus(String userID) {
        return userServce.getUserStatus(userID);
    }
%>

<%
    String userID = request.getParameter("userid");
    String userStatus = getUserStatus(userID);
%>

Finally I would recommend you to NOT use scriptlets and use JSTL tags and libraries like the core-tag-libs and many others, these will help you in the long term.