org.opentripplanner.framework.time.ZoneIdFallback Maven / Gradle / Ivy
package org.opentripplanner.framework.time;
import java.time.ZoneId;
import javax.annotation.Nullable;
import org.opentripplanner.utils.logging.Throttle;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This class provides a fallback mechanism for retrieving a zone id (=time zone).
* If a ZoneId is not provided, it returns a default fallback ZoneId (UTC).
*
* This situation happens when you don't load any transit data into the graph but want to route
* anyway, perhaps only on the street network.
*/
public class ZoneIdFallback {
private static final Logger LOG = LoggerFactory.getLogger(ZoneIdFallback.class);
private static final ZoneId FALLBACK = ZoneId.of("UTC");
private static final Throttle THROTTLE = Throttle.ofOneMinute();
/**
* Accepts a nullable zone id (time zone) and returns UTC as the fallback.
*/
public static ZoneId zoneId(@Nullable ZoneId id) {
if (id == null) {
THROTTLE.throttle(() -> {
LOG.warn(
"Your instance doesn't contain a time zone (which is usually derived from transit data). Assuming {}.",
FALLBACK
);
LOG.warn("Please double-check that transit data was correctly loaded.");
});
return FALLBACK;
} else {
return id;
}
}
}