SQL Developer - where are the spool files stored in sql developer ?

 In a Windows 10 environment, when using SQL Developer 18.1 or higher, the spooled output goes to...

C:\Users\<myuserid>\AppData\Roaming\SQL Developer

which is the directory shown in the Help -> About -> Properties tab for both the ide.pref.dir and ide.user.dir properties.

                                                                                                                             contributed by Vikram Kotwani