JSP - Use request in a method

JSP pages are translated into Servlets and then compiled.

There is a difference in how the translation treats Scriptlets (% with%) and Declarations ( <% %> ).

Scritplets are translated into a service method that provides variables such as <%! %> and request . For example, your Scriptlet is translated into the following build in Tomcat 8 / Jasper:

public void _jspService(final HttpServletRequest request, 
        final HttpServletResponse response) throws IOException, ServletException {

    final PageContext pageContext;
    HttpSession session = null;
    final ServletContext application;
    final ServletConfig config;
    JspWriter out = null;
    final Object page = this;
    JspWriter _jspx_out = null;
    PageContext _jspx_page_context = null;

    try {
        pageContext = _jspxFactory.getPageContext(this, request, response,
                null, true, 8192, true);
        _jspx_page_context = pageContext;
        application = pageContext.getServletContext();
        config = pageContext.getServletConfig();
        session = pageContext.getSession();
        out = pageContext.getOut();
        _jspx_out = out;

        // Aqui esta o seu codigo real
        RequestDispatcher disp = request.getRequestDispatcher("t2.jsp");
        disp.forward(request, response);
    } catch (Throwable t) {
        // linhas e linhas de boilerplate    
    } finally {
        _jspxFactory.releasePageContext(_jspx_page_context);
    }
}

See that you can only use response since it was passed to the service method per parameter.

Declarations are simply copied into the Servlet body during translation, so you will not have access to request by default. Nothing prevents you from receiving request and request as parameters:

<%!
  public void method(HttpServletRequest request, HttpServletResponse response) 
          throws ServletException, IOException {
      RequestDispatcher disp = request.getRequestDispatcher("t2.jsp");
      disp.forward(request, response);
  };
%>

This is equivalent to declaring a method in the body of a response . According to the answer from Max Rogério , just declaring the method is not enough. It is necessary to invoke the method that has been declared. For this, a possible option is to write a Scriptlet that invokes the method by passing Servlet and request :

<%
  method(request, response);
%>

This does what you want ... That said, I see little reason to do a foward this way since the JSP provides the tag response that does the same thing:

<jsp:forward page="t2.jsp" />

In general it is better to avoid Scriptlets and Declarations , besides being a legacy technology, architecturally they are an abomination ... Mix business code with navigation rules and the view in one place creates a very difficult salad to keep.

You create methods or functions so that you do not rewrite repeating things. In your case you just created a method and nothing else. For it to work you have to call it.

// criando metodo ou funcao
public void method()
{
    //sequencia de código que será executada ao chamar metodo ou funcao
    RequestDispatcher disp = request.getRequestDispatcher("t2.jsp");
    disp.forward(request, response);
};

//utilizando metodo ou funcao
method();

In case if you were in some class it would look something like this

public class Teste{
// criando metodo ou funcao
public void mudaTela()
{
    //sequencia de código que será executada ao chamar metodo ou funcao
    RequestDispatcher disp = request.getRequestDispatcher("t2.jsp");
    disp.forward(request, response);
};
}

//na pagina do jsp vc faz import da class
Teste t = New Teste();
t.mudaTela();

I have not tested the codes. But the idea is that when you create a method, you have to call it to execute it.