How to add a method to a jsp page?

[James Hodgkiss]

I've got this jsp code, and I want to add a method to it - how do I do it?!...

<%@ page import="java.util.*" %>
<%@ page import="java.net.*" %>
<%@ page import="java.io.*" %>
 
<%
// read post from PayPal system and add 'cmd'
Enumeration en = request.getParameterNames();
String str = "cmd=_notify-validate";
while(en.hasMoreElements()){
    String paramName = (String)en.nextElement();
    String paramValue = request.getParameter(paramName);
    str = str + "&" + paramName + "=" + URLEncoder.encode(paramValue, "UTF-8");
}
 
// post back to PayPal system to validate
// NOTE: change http: to https: in the following URL to verify using SSL (for increased security).
// using HTTPS requires either Java 1.4 or greater, or Java Secure Socket Extension (JSSE)
// and configured for older versions.
URL u = new URL("https://www.paypal.com/cgi-bin/webscr");
URLConnection uc = u.openConnection();
uc.setDoOutput(true);
uc.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
PrintWriter pw = new PrintWriter(uc.getOutputStream());
pw.println(str);
pw.close();
 
BufferedReader in = new BufferedReader(
new InputStreamReader(uc.getInputStream()));
String res = in.readLine();
in.close();
 
// assign posted variables to local variables
String itemName = request.getParameter("item_name");
String itemNumber = request.getParameter("item_number");
String paymentStatus = request.getParameter("payment_status");
String paymentAmount = request.getParameter("mc_gross");
String paymentCurrency = request.getParameter("mc_currency");
String txnId = request.getParameter("txn_id");
String receiverEmail = request.getParameter("receiver_email");
String payerEmail = request.getParameter("payer_email");
 
//check notification validation
System.err.println("");
System.err.println("res: " + res);
if(res.equals("VERIFIED")) {
    // check that paymentStatus=Completed
    if (paymentStatus.equalsIgnoreCase("Completed")) {
        //CALL SOME METHODS FROM HERE - BUT HOW TO INSERT THE METHODS?!
    }
    else {
        //payment is "Pending" or "Failed"
    }
    
    // check that receiverEmail is your Primary PayPal email
    // check that paymentAmount/paymentCurrency are correct
    // process payment
}
else if(res.equals("INVALID")) {
    // log for investigation
}
else {
    // error
}
 
%>

...do I HAVE to go the servlet route?

Cheers,
James

[Bear Bibeault]

Why add a method to the page? Why not factor any processing out into a bean that you can call. Adding code to a JSP is not just one, but two levels of conventional patterns and practices out of date.

[James Hodgkiss]

I'm new to JSP. Would you be able to give me a link where I can find an example of how to do that? Or can you provide an example?

Thanks,
James
[ November 01, 2007: Message edited by: James Hodgkiss ]

[Bear Bibeault]

Are you also new to Java? If not, just create a bean like any other that provides the method you need.

Using beans from a JSP will be covered in any JSP tutorial worth its salt.

[James Hodgkiss]

No, I'm not new to Java - I just don't know how to call a bean from jsp. I am new to jsp.

[Bear Bibeault]

Short version:

<jsp:useBean id="whatever" class="com.whatever.WhateverBean"/>
 
<%
   whatever.doSomethingWonderful();
%>    

You really need to work through a JSP tutorial before going much further.

[sudhir nim]

if possible, dont declare any methods in jsp.
But if you must do it, you thn you can declare a method in declaration

    
<%! 
   public void somemethod(){ }
 
%>

<%! %> is called declaration

[Bear Bibeault]

Originally posted by sudhir nim:
<%! %> is called declaration

The use of declaration is not advised -- especially for those new to JSP. Delcarations are the easiest way to introduce thread-safety issues into a JSP.