java - Standard/Uniform way to locate files inside and outside JAR file? -

what uniform or standard way locate , access files inside , outside jar files.

i have injarclass() defined in jar file contains configuration text files. extend class in host project have more configurations.

let have inside jar :

config/default.conf 

then in host project :

class myclass extends injarclass { .... } 

and :

config/test.conf 

then run :

xenv=test java myclass

the whole configuration process happens inside injarclass(), based on environment xenv. see injarclass() have access both :

<jar>/config/default.conf <host_app_dir>/config/test.conf 

so repeat question there uniform way access both, if directory structure mirror each other.

if place both current directory , .jar file in classpath:

xenv=test java -classpath .:myjarfile.jar myclass 

you can this:

string configfile =     "/config/" +     system.getenv().getordefault("xenv", "default") +     ".conf";  inputstream config = myclass.class.getresourceasstream(configfile);  if (config == null) {     throw new filenotfoundexception(         "cannot locate " + configfile + " in classpath"); } 

this works because application resource resource java searches within each location in classpath. getresourceasstream first search requested path relative first classpath location, .. if not find file name, @ second classpath location, myjarfile.jar, , seeing .jar file, search requested file inside .jar.