Core Servlets and JavaServer Pages™

10.3. JSP Scriptlets

If you want to do something more complex than insert a simple expression, JSP scriptlets let you insert arbitrary code into the servlet's _jspService method (which is called by service). Scriptlets have the following form:

<% Java Code %>

Scriptlets have access to the same automatically defined variables as expressions (request, response, session, out, etc.; see Section 10.5). So, for example, if you want output to appear in the resultant page, you would use the out variable, as in the following example.

<%
String queryData = request.getQueryString();
out.println("Attached GET data: " + queryData);
%>

In this particular instance, you could have accomplished the same effect more easily by using the following JSP expression: ...