I'm seeing someone getting this issue with the latest version 8 of java but I'm not with version 7.
Can someone here w/ 8 confirm that it works and this isn't a "JavaUpToDate() {return versionNumber.first = '7'}" issue?
If you're using the Steam version and Java is causing trouble, try to enable the latest nightly (rightclick on rising world -> properties -> betas -> nightly 29.12 win 8 fix + own JVM). It uses an own JVM, so it should not matter what version is installed on your computer.