MissingResourceException for Resource in Classpath

Question

I'm having serious trouble trying to load a resource into a bundle in my application. I've been at this for hours and I really don't know what I'm doing wrong.

I have a Java application where I'm attempting to apply internationalization to my logging. Everything works fine in Eclipse, it's only when I attempt to deploy the compiled jars to the test environment that the properties file cannot be located. My properties file is called logging_en.properties. I've verified that it's on the file system (Linux, by the way). When I launch my application, I execute the following command:

$JAVA_HOME/bin/java -verbose:gc -Xloggc:/var/tmp/app_gc.log -Xms1000m -Xms1000m  -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:NewRatio=3  -classpath $CLASSPATH -Djava.rmi.server.codebase=file:///data/dev/app/common/ext/dirmi-1.1.1.jar -Djava.awt.headless=true -Dcom.sun.management.jmxremote.port=xxx -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false $JAVA_SECURITY $IMPORT_PROPERTIES $APP_PROPERTIES app.serverimpl.ServerStarter

My CLASSPATH variable is:

/data/dev/app/server/logging_en.properties:/data/dev/app/common/lib/common.jar:/data/dev/app/common/ext/dirmi-1.1.1.jar:/data/dev/app/common/ext/log4j-1.2.17.jar:/data/dev/app/common/ext/cojen-2.2.3.jar:/data/dev/app/common/lib/server.jar

The properties file is in my classpath. In the code itself, the exact line I run is:

LogManager.getLogger("server").setResourceBundle(java.util.ResourceBundle.getBundle("logging"));

At the very beginning when the server starts, I invariably get the Missing Resource exception:

Exception in thread "main" java.util.MissingResourceException: Can't find bundle for base name logging, locale en_US

Just to be safe, I've gone so far as to copy the file to logging.properties and logging_en_US.properties and added all three to my classpath. Still the same issue. I know I'm doing something stupid or missing something obvious, but I'm really at a loss. I'd prefer not to bundle the file into my jar so it can be modified on the fly, so I'm hoping it's possible to do this from the classpath.

Answer 1

For individual files, the classpath needs to contain the folder where the files(s) are located, not the path to the actual file itself. Change your classpath to read like:

/data/dev/app/server/:/data/dev/app/common/lib/common.jar:...

(Jar files are treated like folders, as you can see above).

To be clear - the ResourceBundle.getBundle("logging") call is going to be doing the equivalent of something like this internally:

ClassLoader.getSystemClassLoader().getResource("logging_en.properties")

and when it does that, it will look for that path ("logging_en.properties") in the folders on the classpath - which means it will look in /data/dev/app/server and then inside the /data/dev/app/common/lib/common.jar file (it has a cache of the unzipped contents of it) and so on. (There is more pluggability involved and not all class loaders have to correspond to files, etc. - but in the common case the above is what does occur.)