Java is sometimes difficult to set up properly, because there are run-time environments (JRE) and Java development kits (JDK) and furthermore you need the right versions and need to set up proper Windows environment variable paths.
Steps To Set Up Java For Modding
- Download an appropriate JDK (not JRE!). At time of writing the Kit 7 was most compatible with modding, downloadable from http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html. Make sure you choose the version appropriate to your computer (in my case Windows x64).
- Install the JDK following the instructions.
- Ensure the Windows path variables are set up. You probably need to create a JAVA_HOME system variable, as follows
4. Add to the Path system variable (and for good measure create PATH system variable) using similar method to above but add to existing path using semi-colon separator and then putting the path to the \bin folder inside the path you used for JAVA_HOME.