defining/exporting environement variables from tomcat server

[Karl Krasnowsky]

Tomcat 6

While I can find reams of information on setting up an OS environment for running tomcat, I'd like to define a variable within tomcat so that when my jsp's and supporting bean code run they can utilize these variables at server runtime.

Hoping this is pretty obvious, but where/how are such variables defined within the Tomcat configuration system?

In JBoss I can do this by defining such properties in the deploy/properties-service.xml
Is there a like process for doing this in vanilla Tomcat?

thanks,
Karl

[Tim Holloway]

I'm not sure I understood that, but if you're saying what I'm thinking you're saying, you can define a resource property and use JNDI code in the app to get its value. Simple property values can be read directly that way. If you have lots of properties, setup a simple property that locates the property set. Something like the absolute path of an externally-supplied properties file or a jdbc URL.

[Karl Krasnowsky]

Tim Holloway wrote:I'm not sure I understood that, but if you're saying what I'm thinking you're saying, you can define a resource property and use JNDI code in the app to get its value. Simple property values can be read directly that way. If you have lots of properties, setup a simple property that locates the property set. Something like the absolute path of an externally-supplied properties file or a jdbc URL.

Well, I need something even more basic.

In JBoss you can simply do something like this:

<property name="myProp">c:/foo/bar</property>

and (I assume) on jvm startup of the server it simply appends this to the property set so in your code you can do this:

System.getProperty("myProp");

and there you go... no special context mapping, just a basic property call.

[Tim Holloway]

You should be able to do that in Tomcat by creating a "setenv.bat" or "setenv.sh" file (depending on OS) in TOMCAT_HOME/bin. Put this line in it:

JAVA_OPTS="-DmyProp=xxxx"

Caution: because this is a System property, it will apply to ALL java code in the Tomcat JVM. Sometimes per-application properties are preferable. Also, since it's outside of the direct scope of J2EE, there can be maintenance issues involved, since most of us don't think of externally-imposed properties as part of the webapp and therefore don't go looking for them when we deploy to a new server or something like that.

Actually, I've never used a simple property setting in JBoss, and I'm not sure what caveats are attached to it. As I said, it's not standard J2EE usage.