support directory in jar

[wangshihui]

support directory in jar, classloader method: classloader.getResource(entryName) when the entryName is a drectory ,this method would return null.In some opensource tools use this feature to load the resouces in the same folder
would faile

Resolves #314

[Ladicek]

Ah so this is to retain the directory structure in a JAR that is being reindexed. That seems sensible, but I'm not sure about the code that follows the if that's modified here -- does it handle directory entries correctly? I'd expect problems there.

[wangshihui]

Ah so this is to retain the directory structure in a JAR that is being reindexed. That seems sensible, but I'm not sure about the code that follows the if that's modified here -- does it handle directory entries correctly? I'd expect problems there.

I test in my project after modification，every thing works ok. and we cuurently store and use it in our private repository.

if exlude the dirctory structure from the jar, classloader.getResource("") would retrun null. so if application want to get all resources from a named directory is complexed.
eg： get the all properties from classpath:config, should walk through all the entries. then filer the prefix with config

also: a lot of opensource tools use this feature of classloader.getResources(dirctory), if no direcotry enty in the jar file，these tools can not work 。