Java TemporalAccessor.isSupported方法代码示例

import java.time.temporal.TemporalAccessor; //导入方法依赖的package包/类
private void crossCheck(TemporalAccessor target) {
    for (Iterator<Entry<TemporalField, Long>> it = fieldValues.entrySet().iterator(); it.hasNext(); ) {
        Entry<TemporalField, Long> entry = it.next();
        TemporalField field = entry.getKey();
        if (target.isSupported(field)) {
            long val1;
            try {
                val1 = target.getLong(field);
            } catch (RuntimeException ex) {
                continue;
            }
            long val2 = entry.getValue();
            if (val1 != val2) {
                throw new DateTimeException("Conflict found: Field " + field + " " + val1 +
                        " differs from " + field + " " + val2 + " derived from " + target);
            }
            it.remove();
        }
    }
}
 

import java.time.temporal.TemporalAccessor; //导入方法依赖的package包/类
@Override
public boolean format(DateTimePrintContext context, StringBuilder buf) {
    ZoneId zone = context.getValue(TemporalQueries.zoneId());
    if (zone == null) {
        return false;
    }
    String zname = zone.getId();
    if (!(zone instanceof ZoneOffset)) {
        TemporalAccessor dt = context.getTemporal();
        int type = GENERIC;
        if (!isGeneric) {
            if (dt.isSupported(ChronoField.INSTANT_SECONDS)) {
                type = zone.getRules().isDaylightSavings(Instant.from(dt)) ? DST : STD;
            } else if (dt.isSupported(ChronoField.EPOCH_DAY) &&
                       dt.isSupported(ChronoField.NANO_OF_DAY)) {
                LocalDate date = LocalDate.ofEpochDay(dt.getLong(ChronoField.EPOCH_DAY));
                LocalTime time = LocalTime.ofNanoOfDay(dt.getLong(ChronoField.NANO_OF_DAY));
                LocalDateTime ldt = date.atTime(time);
                if (zone.getRules().getTransition(ldt) == null) {
                    type = zone.getRules().isDaylightSavings(ldt.atZone(zone).toInstant()) ? DST : STD;
                }
            }
        }
        String name = getDisplayName(zname, type, context.getLocale());
        if (name != null) {
            zname = name;
        }
    }
    buf.append(zname);
    return true;
}
 

import java.time.temporal.TemporalAccessor; //导入方法依赖的package包/类
/**
 * Obtains an instance of {@code ZonedDateTime} from a temporal object.
 * <p>
 * This obtains a zoned date-time based on the specified temporal.
 * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
 * which this factory converts to an instance of {@code ZonedDateTime}.
 * <p>
 * The conversion will first obtain a {@code ZoneId} from the temporal object,
 * falling back to a {@code ZoneOffset} if necessary. It will then try to obtain
 * an {@code Instant}, falling back to a {@code LocalDateTime} if necessary.
 * The result will be either the combination of {@code ZoneId} or {@code ZoneOffset}
 * with {@code Instant} or {@code LocalDateTime}.
 * Implementations are permitted to perform optimizations such as accessing
 * those fields that are equivalent to the relevant objects.
 * <p>
 * This method matches the signature of the functional interface {@link TemporalQuery}
 * allowing it to be used in queries via method reference, {@code ZonedDateTime::from}.
 *
 * @param temporal  the temporal object to convert, not null
 * @return the zoned date-time, not null
 * @throws DateTimeException if unable to convert to an {@code ZonedDateTime}
 */
public static ZonedDateTime from(TemporalAccessor temporal) {
    if (temporal instanceof ZonedDateTime) {
        return (ZonedDateTime) temporal;
    }
    try {
        ZoneId zone = ZoneId.from(temporal);
        if (temporal.isSupported(INSTANT_SECONDS)) {
            long epochSecond = temporal.getLong(INSTANT_SECONDS);
            int nanoOfSecond = temporal.get(NANO_OF_SECOND);
            return create(epochSecond, nanoOfSecond, zone);
        } else {
            LocalDate date = LocalDate.from(temporal);
            LocalTime time = LocalTime.from(temporal);
            return of(date, time, zone);
        }
    } catch (DateTimeException ex) {
        throw new DateTimeException("Unable to obtain ZonedDateTime from TemporalAccessor: " +
                temporal + " of type " + temporal.getClass().getName(), ex);
    }
}
 

import java.time.temporal.TemporalAccessor; //导入方法依赖的package包/类
/**
 * Obtains an instance of {@code ZonedDateTime} from a temporal object.
 * <p>
 * This obtains a zoned date-time based on the specified temporal.
 * A {@code TemporalAccessor} represents an arbitrary set of date and time information,
 * which this factory converts to an instance of {@code ZonedDateTime}.
 * <p>
 * The conversion will first obtain a {@code ZoneId} from the temporal object,
 * falling back to a {@code ZoneOffset} if necessary. It will then try to obtain
 * an {@code Instant}, falling back to a {@code LocalDateTime} if necessary.
 * The result will be either the combination of {@code ZoneId} or {@code ZoneOffset}
 * with {@code Instant} or {@code LocalDateTime}.
 * Implementations are permitted to perform optimizations such as accessing
 * those fields that are equivalent to the relevant objects.
 * <p>
 * This method matches the signature of the functional interface {@link TemporalQuery}
 * allowing it to be used as a query via method reference, {@code ZonedDateTime::from}.
 *
 * @param temporal  the temporal object to convert, not null
 * @return the zoned date-time, not null
 * @throws DateTimeException if unable to convert to an {@code ZonedDateTime}
 */
public static ZonedDateTime from(TemporalAccessor temporal) {
    if (temporal instanceof ZonedDateTime) {
        return (ZonedDateTime) temporal;
    }
    try {
        ZoneId zone = ZoneId.from(temporal);
        if (temporal.isSupported(INSTANT_SECONDS)) {
            long epochSecond = temporal.getLong(INSTANT_SECONDS);
            int nanoOfSecond = temporal.get(NANO_OF_SECOND);
            return create(epochSecond, nanoOfSecond, zone);
        } else {
            LocalDate date = LocalDate.from(temporal);
            LocalTime time = LocalTime.from(temporal);
            return of(date, time, zone);
        }
    } catch (DateTimeException ex) {
        throw new DateTimeException("Unable to obtain ZonedDateTime from TemporalAccessor: " +
                temporal + " of type " + temporal.getClass().getName(), ex);
    }
}