use:
java.exe -jar echoserver.jar
Starts up an echo server or port 8081.  You can then test
your HTML forms or other CGI client code by using
http://localhost:8081 instead of your usual server.  It
displays whatever your browser sends on the console,
character for character without any interpretation.
It does not send it back to your browser.
This is an extremely simple program, designed to show the
elements of how a server works.  It is not a full-featured
debugging tool by any means.
To install, Extract the zip download with WinZip, available
from http://www.winzip.com (or similar unzip utility) into
any directory you please, often C:\ -- ticking off the "user
folder names" option. To run as an application, type:
java.exe -jar C:\com\mindprod\echoserver\echoserver.jar
adjusting as necessary to account for where the jar file is.
Echoserver is misnamed because it does not actually echo
what it receives back back to the browser. It just dumps it
on the console.