Maxmind's Java API getOrg causes IOExceptions when in Google App Engine, but not in standard Java

Question

I bought a site license for the GeoIP ISP database from Maxmind, and decided to implement it within my Google App Engine project.

I tested my own External IP with a regular Java project which used the same API/JAR and was able to resolve it to Comcast.

Implementing it within Google App Engine has been a pain. Using the same exact call (my own external IP), I received various IOExceptions, specifically EOFExceptions whenever using the standard LookupService (read from file) and OutOfBoundsArrayExceptions whenever using the memory-based LookupService.

Some specific information: The database file size should NOT be an issue. It is around ~3mb. You can find the API open sourced here : https://github.com/maxmind/geoip-api-java

I will eventually figure out this issue but it seems to be fairly low-level so it may take some time. I was wondering if anyone else had any issues.

UPDATE- I've just confirmed the .dat file's MD5 changes whenever checked using Commons Codec 1.8 DigestUtils.md5Hex.

It is different from the working files' MD5.

Answer 1

Fixed...

For some reason, having the .dat file in my WEB-INF was altering it significantly. The MD5 checksum was not the same.

Taking it one root above to my "webapp" folder which housed WEB-INF somehow escaped the changing of the file and the MD5 validated...

Might have to file a bug with Google for this one, or I'm misunderstanding something entirely...

UPDATE: Upon further introspection I've decided that it might of been the text set that my WEB-INF was using... UTF-8. This is the only thing I can think of.