io.dropwizard.jdbi.args.ZonedDateTimeMapper Maven / Gradle / Ivy
package io.dropwizard.jdbi.args;
import org.skife.jdbi.v2.StatementContext;
import org.skife.jdbi.v2.tweak.ResultColumnMapper;
import javax.annotation.Nullable;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Timestamp;
import java.time.Instant;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.Optional;
import java.util.TimeZone;
/**
* A {@link ResultColumnMapper} to map {@link ZonedDateTime} objects.
*/
public class ZonedDateTimeMapper implements ResultColumnMapper {
/**
* {@link Calendar} for representing a database time zone.
* If a field is not represented in a database as
* {@code TIMESTAMP WITH TIME ZONE}, we need to set its time zone
* explicitly. Otherwise it will not be correctly represented in
* a time zone different from the time zone of the database.
*/
private Optional calendar;
public ZonedDateTimeMapper() {
calendar = Optional.empty();
}
public ZonedDateTimeMapper(Optional timeZone) {
calendar = timeZone.map(GregorianCalendar::new);
}
/**
* Make a clone of a calendar.
* Despite the fact that {@link Calendar} is used only for
* representing a time zone, some JDBC drivers actually use it
* for time calculations,
* Also {@link Calendar} is not immutable, which makes it
* thread-unsafe. Therefore we need to make a copy to avoid
* state mutation problems.
*
* @return a clone of calendar, representing a database time zone
*/
private Optional cloneCalendar() {
return calendar.map(Calendar::clone).map(x -> (Calendar)x);
}
@Override
@Nullable
public ZonedDateTime mapColumn(ResultSet r, int columnNumber, StatementContext ctx) throws SQLException {
final Optional instance = cloneCalendar();
final Timestamp timestamp = instance.isPresent() ? r.getTimestamp(columnNumber, instance.get()) :
r.getTimestamp(columnNumber);
return convertToZonedDateTime(timestamp);
}
@Override
@Nullable
public ZonedDateTime mapColumn(ResultSet r, String columnLabel, StatementContext ctx) throws SQLException {
final Optional instance = cloneCalendar();
final Timestamp timestamp = instance.isPresent() ? r.getTimestamp(columnLabel, instance.get()) :
r.getTimestamp(columnLabel);
return convertToZonedDateTime(timestamp);
}
@Nullable
private ZonedDateTime convertToZonedDateTime(Timestamp timestamp) {
if (timestamp == null) {
return null;
}
final Optional zoneId = calendar.flatMap(c -> Optional.of(c.getTimeZone().toZoneId()));
return ZonedDateTime.ofInstant(
Instant.ofEpochSecond(timestamp.getTime() / 1000, timestamp.getNanos()),
zoneId.orElse(ZoneId.systemDefault()));
}
}