Make per-context JNDI variable available to Tomcat in Eclipse

Question

I'm using Tomcat 8.5.6 inside Eclipse 4.6.1. I have my web-app project/context foo, which has a JAX-RS (using RESTEasy 3.1.0.CR3) endpoint of bar, so I can fire up Tomcat inside Eclipse and access:

http://localhost:8080/foo/bar

I have a variable named foobar which I want to access inside my JAX-RS implementation using JNDI:

final String foobar = (String) new InitialContext().lookup("java:comp/env/foobar");

I plan on deploying the produced WAR in production using Tomcat autodeploy. I want to configure the foobar variable for Tomcat externally to the WAR. How can I do that so that I can test it in Eclipse?

After a lot of reading, I found what I thought to be the $CATALINA_HOME of Eclipse: …\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\. So I created a context file for foo at …\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\conf\Catalina\localhost\foo.xml to correspond to my project/context, and put the following inside it:

<?xml version="1.0" encoding="UTF-8"?>
<Context>
    <Environment name="foobar" type="java.lang.String" value="123"/>
</Context>

Yes, I know that Eclipse erases this directory whenever I rebuild. But after building, I saved to file at least want to see if it works. It doesn't. I get an error:

javax.naming.NameNotFoundException: Name [foobar] is not bound in this Context. Unable to find [foobar].

I want to at least get it working so I can know how to do this in production, and worry later about the context file deletion thing in Eclipse. So what did I do wrong? Why can't Tomcat in Eclipse find this JNDI variable?

Note: I am not using a web.xml file and have no desire to do so; besides, this variable should be defined outside the WAR in the production deployment.

Update: The good news is that (on Windows 10 Professional Anniversary Edition 64-bit) using the same Tomcat but in standalone mode, I put the same foobar.xml file inside the standalone Tomcat's conf\Catalina\localhost\foo.xml, and my JAX-RS application picked it up just fine. So how can I define a JNDI variable in Tomcat inside Eclipse for testing?

Answer 1

Your link to Markus' answer on https://stackoverflow.com/a/22380248/1794485 allowed me to get this working, or at least as described in his workaround. But the remaining problem to solve was ordering.

As he said, you can workaround this by having a local copy of the META-INF/context.xml somewhere else, and adding this folder to the Deployment Assembly in the project properties of the Eclipse project.

This didn't pick up for me initially though. It looks like that while the Deployment Assembly in the properties shows as sorted by name, in fact it has an order like any other path. When I then removed the src/main/webapp entry (so the one containing the normal META-INF/context.xml) and added it back in, this effectively moved it down the pecking order. The next Tomcat deploy and startup in Eclipse finally put my preferred copy of META-INF/context.xml in .metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\myapp\META-INF

If in doubt about the true sequence of that Deployment Assembly path, have a look under your Eclipse project on the file system - at .settings\org.eclipse.wst.common.component.

Answer 2

It appears that in order to get Eclipse+Tomcat to recognize the per-module context files, you have to go into the server configuration (double-click on the server) and turn on the Publish module contexts to separate XML files. This way Tomcat will use the specific context XML file you created. Otherwise it apparently puts them in conf/server.xml and ignores the context-specific file you created.

There is still the problem that Eclipse regenerates this file each time you do a rebuild, destroying whatever JNDI variables you placed there. I'm trying to get the workaround in https://stackoverflow.com/a/22380248/421049 to work, but not yet succeeding. Anyone have any better ideas?

At least I'm able to reproduce a production environment now --- albeit temporarily, until the next rebuild.