Java preferences api

snapcraft
1

Has anyone used the Java Preferences API with snaps? I’m hoping there is an environment variable that can be set to point the preferences storage inside SNAP_USER_DATA. If I use the preferences API as is, I get permissions errors:

Apr 29, 2019 12:13:10 PM java.util.prefs.FileSystemPreferences$6 run
WARNING: Prefs file removed in background /home/jsseidel/.java/.userPrefs/_!':!bw"t!#4!cw"w!'`!bg"j!'`!cg"z!'`!a@"k!'`!b!!u!%o![w"h!'w!}@"4!'k!}@"u/prefs.xml
Exception in thread "Sync Timer Thread" java.lang.SecurityException: Could not lock User prefs. Lock file access denied.

I think this happens because snaps cannot access dot files in the home directory.

Any ideas?

2

Answering my own question. You can set the values for java.utils.prefs.userRoot and java.utils.prefs.systemRoot like in this example:

java -Djava.util.prefs.userRoot="$SNAP_USER_DATA" -jar some.jar

In your java run wrapper. This allows the normal Java Preferences API to work with snaps.

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