I'd suggest the following workaround:
1) Run the installer with -is:extract parameterб e.g.
./jstudio_ent81-beta-linux.sh -is:extract
This will extract the installer jar file either in the current directory, or in a subdirectory named isXXXXXXXXXXX (where X is a number).
2) Then run the jar file, setting the heap space, etc:
java -Xmx1024m -jar jstudio_ent81-beta-linux.jar