Jetty - set system property

Question

I run webapp on Jetty. The configuration for the app come from file that lives on the same server where Jetty is running. Inside the app I rely on the system property to obtain path to the file so I can parse it. E.g.

final String loc = System.getProperty(FACTORY);

Now I can start jetty with D switch to provide $FACTORY on the command line but I rather put it in jetty.xml if I can. I know there is <SystemProperty /> tag but that seems to just provide system value that already exists for the <Set/> tag. Can someone give me example how this can be achieved? (If it can be achieved)

Answer 1

To configure a web application it is better to avoid system properties and to use JNDI instead.

Recently I posted an example on how to accomplish that with Jetty.

Answer 2

I'm going to accept @vanje answer since it got me thinking into right direction. Here's what I ended up using:

1. Create jetty-web.xml outside of your WAR distro (no you don't want to package it with WAR if you want to configure the app from "outside")
2. Place jetty-web.xml alongside of jetty.xml
3. I needed just a single parameter so I ended up with the following:

jetty-web.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE Configure PUBLIC "-//Mort Bay Consulting//DTD Configure//EN"    
     "http://jetty.mortbay.org/configure.dtd"&gt;
<Configure class="org.mortbay.jetty.webapp.WebAppContext">
    <New class="org.mortbay.jetty.plus.naming.EnvEntry">
        <Arg>myOwnParam</Arg>
        <Arg type="java.lang.String">//some/path/to/the/file</Arg>
    </New>
</Configure>

Java snippet

    InitialContext c = new InitialContext();
    EnvEntry env = (EnvEntry)
         c.lookup("org.mortbay.jetty.plus.naming.EnvEntry/myOwnParam");
    final String myString = (String) env.getObjectToBind();

The biggest gotcha for me here was that I was trying to get myString from the defaul env which didn't work until I realized that JNDI was using local context. This is OK for me but will break portability if you try to move WAR on say Tomcat. If someone can post an example how this can be saved into default context that would be greatOwnParam