HTTPServletRequest.getParameterNames() not in order as in HTML Form

Question

I have an html form which posts data to a servlet. However the order returned in getParameterNames() isn't the same as in the HTML Form.

How do i retrieve the parameters in the same order?

maybe this helps: http://stackoverflow.com/a/4733472/3377857 — Klemens Morbe, Mar 27 '14 at 10:49
possible duplicate of [Order of request.getParameterNames()](http://stackoverflow.com/questions/4733373/order-of-request-getparameternames) — Santino 'Sonny' Corleone, Mar 27 '14 at 11:03
Your server logic should not depend on the parameters's order. Rework it — robermann, Mar 27 '14 at 11:19

score 1 · Accepted Answer · answered Mar 28 '14 at 04:50

The parameters in the request are stored in a Map. A map do not warranty the order of iteration. If you really need to get the records in a particular order I suggest to add the order in the name property something like 01_firstName 02_last name and then order the map.

score 1 · Answer 2 · answered Mar 28 '14 at 09:26

This came up as a bug in Apache Tomcat a little while ago. The short version of that bug report is:

Section 17.13.3 of the HTML specification (v4.01) titled "Processing form data", clearly states that "control names/values are listed in the order they appear in the document."
The Servlet specification does defer to W3C for all HTML matters.
Strictly, 17.13.3 applies to how the client presents the data to the server
That said, it seems reasonable to expect Servlet containers to retain this order when presenting parameters.

This has been fixed in Tomcat 8.0.x for 8.0.0-RC4 onwards and in 7.0.x for 7.0.45 onwards.

HTTPServletRequest.getParameterNames() not in order as in HTML Form

2 Answers2