TunnelliJ: User's Guide

I want to sniff and look at calls between client I develop and the Web Service running at http://tomcat:8080/service.

Start TunnelliJ with these parameters:

4444 as port where it listens
tomcat as destination hostname
8080 as destination port

Force your client to open connections to localhost:4444 (not directly to tomcat:8080). E.g. change the constant used in your code when opening connection and recompile the class).

Alternatively you can force your client to use port 4444 by setting HTTP proxy parameters to your JVM:
-Dhttp.proxyHost=localhost -Dhttp.proxyPort=4444

In this case JVM will try to redirect all HTTP connections at port 4444, thinking there is a proxy. Tunnel will forward all incoming traffic to specifed host and port.

Run your client. You should see all calls as lines in the stored calls list, when you open TunnelliJ window.

One line in the list is one connection opened during communication. One connection can be used for more than one call, for example when server allows HTTP option KeepConnectionAlive.

All outgoing traffic (requests) is in the left side text area, all incoming (replies) is in the right.

You can edit the text areas to be more readable from them, use Ctrl+C and to copy the content.

You also may find useful Wrap/Unwrap button which wraps/unwraps the contect of text areas to be more readable.