What uses the java temp folder?

Out of box Broadleaf will use the `java.io.tmp` folder with `cms` and `ehcache`. 

This can be found in the common/src/main/resources/config/bc/common.properties file:

# If you want to use something besides java.io.tmp for your temp directory, you can set this property to the  
# directory where you want your temporary files to reside 

For the cache, you can see here: common/src/main/resources/bl-common-ehcache.xml
    <diskStore path="java.io.tmpdir"/>