NullPointerException in Configurator about ical4j

[benfortuna]

Keep it open for now, i will have a closer look to see if I can make any improvements. Thanks for reporting.

[benfortuna]

I've made an adjustment to prevent the null pointer exception, by deferring log initialisation until after config is loaded

[raboof]

Ah, looking closer it actually makes sense, as this code is triggered from the initialization of Configurtor.LOG, which is before the initialization of Configurtor.CONFIG. I'll look into this some more (though now I'm confused this doesn't happen during local development :) )

Jul 29 13:16:57 server calendar-export-start[165498]: Exception in thread "main" java.util.ServiceConfigurationError: java.time.zone.ZoneRulesProvider: Provider net.fortuna.ical4j.model.DefaultZoneRulesProvider could not be instantiated
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.util.ServiceLoader.fail(ServiceLoader.java:586)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.util.ServiceLoader$ProviderImpl.newInstance(ServiceLoader.java:813)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.util.ServiceLoader$ProviderImpl.get(ServiceLoader.java:729)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.util.ServiceLoader$3.next(ServiceLoader.java:1403)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.time.zone.ZoneRulesProvider.<clinit>(ZoneRulesProvider.java:177)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.time.ZoneRegion.ofId(ZoneRegion.java:121)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.time.ZoneId.of(ZoneId.java:411)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.time.ZoneId.of(ZoneId.java:359)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.time.ZoneId.of(ZoneId.java:315)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.util.TimeZone.toZoneId0(TimeZone.java:605)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.util.TimeZone.toZoneId(TimeZone.java:582)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.util.TimeZone.toZoneId0(TimeZone.java:594)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.util.TimeZone.toZoneId(TimeZone.java:582)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.time.ZoneId.systemDefault(ZoneId.java:275)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.core.util.CachingDateFormatter.<init>(CachingDateFormatter.java:57)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.core.util.CachingDateFormatter.<init>(CachingDateFormatter.java:52)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.core.util.CachingDateFormatter.<init>(CachingDateFormatter.java:48)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.classic.layout.TTLLLayout.<init>(TTLLLayout.java:40)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.classic.BasicConfigurator.configure(BasicConfigurator.java:51)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.classic.util.ContextInitializer.invokeConfigure(ContextInitializer.java:128)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:103)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:66)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.classic.spi.LogbackServiceProvider.initializeLoggerContext(LogbackServiceProvider.java:52)
Jul 29 13:16:57 server calendar-export-start[165498]:         at ch.qos.logback.classic.spi.LogbackServiceProvider.initialize(LogbackServiceProvider.java:41)
Jul 29 13:16:57 server calendar-export-start[165498]:         at org.slf4j.LoggerFactory.bind(LoggerFactory.java:196)
Jul 29 13:16:57 server calendar-export-start[165498]:         at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:183)
Jul 29 13:16:57 server calendar-export-start[165498]:         at org.slf4j.LoggerFactory.getProvider(LoggerFactory.java:486)
Jul 29 13:16:57 server calendar-export-start[165498]:         at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:472)
Jul 29 13:16:57 server calendar-export-start[165498]:         at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:421)
Jul 29 13:16:57 server calendar-export-start[165498]:         at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:447)
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.util.Configurator.<clinit>(Configurator.java:54)
Jul 29 13:16:57 server calendar-export-start[165498]:         at KalenderAlgemeen$package$.kalenderAlgemeen(KalenderAlgemeen.scala:136)
Jul 29 13:16:57 server calendar-export-start[165498]:         at kalenderAlgemeen.main(KalenderAlgemeen.scala:134)
Jul 29 13:16:57 server calendar-export-start[165498]: Caused by: java.lang.ExceptionInInitializerError
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.model.TemporalAdapter.<clinit>(TemporalAdapter.java:37)
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.model.property.DateProperty.setDate(DateProperty.java:171)
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.model.property.DtStart.<init>(DtStart.java:144)
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.model.TimeZoneLoader.<clinit>(TimeZoneLoader.java:49)
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.model.DefaultZoneRulesProvider.<init>(DefaultZoneRulesProvider.java:32)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:502)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:486)
Jul 29 13:16:57 server calendar-export-start[165498]:         at java.base/java.util.ServiceLoader$ProviderImpl.newInstance(ServiceLoader.java:789)
Jul 29 13:16:57 server calendar-export-start[165498]:         ... 31 more
Jul 29 13:16:57 server calendar-export-start[165498]: Caused by: java.lang.NullPointerException: Cannot invoke "java.util.Properties.getProperty(String)" because "net.fortuna.ical4j.util.Configurator.CONFIG" is null
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.util.Configurator.getProperty(Configurator.java:77)
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.util.TimeZones.getDefault(TimeZones.java:85)
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.model.TemporalComparator.<init>(TemporalComparator.java:27)
Jul 29 13:16:57 server calendar-export-start[165498]:         at net.fortuna.ical4j.model.TemporalComparator.<clinit>(TemporalComparator.java:20)
Jul 29 13:16:57 server calendar-export-start[165498]:         ... 40 more

[raboof]

I've worked around this for now by making sure I'm initializing the logger before touching ical4j.

Do you want to keep this open to try and see if there's any way to avoid it from ical4j, or do you want to close it and consider it SEP?

[raboof]

Great!

And thanks again for such a nice library, the calculateRecurrenceSet was especially helpful - I'm using it to generate some reports and overviews from our shared NextCloud calendar at museum EICAS