* All {@link TemporalField} instances have a valid range of values. * For example, the ISO day-of-month runs from 1 to somewhere between 28 and 31. * This class captures that valid range. *
* It is important to be aware of the limitations of this class. * Only the minimum and maximum values are provided. * It is possible for there to be invalid values within the outer range. * For example, a weird field may have valid values of 1, 2, 4, 6, 7, thus * have a range of '1 - 7', despite that fact that values 3 and 5 are invalid. *
* Instances of this class are not tied to a specific field. * * @implSpec * This class is immutable and thread-safe. * * @since 1.8 */ public final class ValueRange implements Serializable { /** * Serialization version. */ private static final long serialVersionUID = -7317881728594519368L; /** * The smallest minimum value. */ private final long minSmallest; /** * The largest minimum value. */ private final long minLargest; /** * The smallest maximum value. */ private final long maxSmallest; /** * The largest maximum value. */ private final long maxLargest; /** * Obtains a fixed value range. *
* This factory obtains a range where the minimum and maximum values are fixed. * For example, the ISO month-of-year always runs from 1 to 12. * * @param min the minimum value * @param max the maximum value * @return the ValueRange for min, max, not null * @throws IllegalArgumentException if the minimum is greater than the maximum */ public static ValueRange of(long min, long max) { if (min > max) { throw new IllegalArgumentException("Minimum value must be less than maximum value"); } return new ValueRange(min, min, max, max); } /** * Obtains a variable value range. *
* This factory obtains a range where the minimum value is fixed and the maximum value may vary. * For example, the ISO day-of-month always starts at 1, but ends between 28 and 31. * * @param min the minimum value * @param maxSmallest the smallest maximum value * @param maxLargest the largest maximum value * @return the ValueRange for min, smallest max, largest max, not null * @throws IllegalArgumentException if * the minimum is greater than the smallest maximum, * or the smallest maximum is greater than the largest maximum */ public static ValueRange of(long min, long maxSmallest, long maxLargest) { return of(min, min, maxSmallest, maxLargest); } /** * Obtains a fully variable value range. *
* This factory obtains a range where both the minimum and maximum value may vary. * * @param minSmallest the smallest minimum value * @param minLargest the largest minimum value * @param maxSmallest the smallest maximum value * @param maxLargest the largest maximum value * @return the ValueRange for smallest min, largest min, smallest max, largest max, not null * @throws IllegalArgumentException if * the smallest minimum is greater than the smallest maximum, * or the smallest maximum is greater than the largest maximum * or the largest minimum is greater than the largest maximum */ public static ValueRange of(long minSmallest, long minLargest, long maxSmallest, long maxLargest) { if (minSmallest > minLargest) { throw new IllegalArgumentException("Smallest minimum value must be less than largest minimum value"); } if (maxSmallest > maxLargest) { throw new IllegalArgumentException("Smallest maximum value must be less than largest maximum value"); } if (minLargest > maxLargest) { throw new IllegalArgumentException("Minimum value must be less than maximum value"); } return new ValueRange(minSmallest, minLargest, maxSmallest, maxLargest); } /** * Restrictive constructor. * * @param minSmallest the smallest minimum value * @param minLargest the largest minimum value * @param maxSmallest the smallest minimum value * @param maxLargest the largest minimum value */ private ValueRange(long minSmallest, long minLargest, long maxSmallest, long maxLargest) { this.minSmallest = minSmallest; this.minLargest = minLargest; this.maxSmallest = maxSmallest; this.maxLargest = maxLargest; } //----------------------------------------------------------------------- /** * Is the value range fixed and fully known. *
* For example, the ISO day-of-month runs from 1 to between 28 and 31. * Since there is uncertainty about the maximum value, the range is not fixed. * However, for the month of January, the range is always 1 to 31, thus it is fixed. * * @return true if the set of values is fixed */ public boolean isFixed() { return minSmallest == minLargest && maxSmallest == maxLargest; } //----------------------------------------------------------------------- /** * Gets the minimum value that the field can take. *
* For example, the ISO day-of-month always starts at 1. * The minimum is therefore 1. * * @return the minimum value for this field */ public long getMinimum() { return minSmallest; } /** * Gets the largest possible minimum value that the field can take. *
* For example, the ISO day-of-month always starts at 1. * The largest minimum is therefore 1. * * @return the largest possible minimum value for this field */ public long getLargestMinimum() { return minLargest; } /** * Gets the smallest possible maximum value that the field can take. *
* For example, the ISO day-of-month runs to between 28 and 31 days. * The smallest maximum is therefore 28. * * @return the smallest possible maximum value for this field */ public long getSmallestMaximum() { return maxSmallest; } /** * Gets the maximum value that the field can take. *
* For example, the ISO day-of-month runs to between 28 and 31 days. * The maximum is therefore 31. * * @return the maximum value for this field */ public long getMaximum() { return maxLargest; } //----------------------------------------------------------------------- /** * Checks if all values in the range fit in an {@code int}. *
* This checks that all valid values are within the bounds of an {@code int}. *
* For example, the ISO month-of-year has values from 1 to 12, which fits in an {@code int}. * By comparison, ISO nano-of-day runs from 1 to 86,400,000,000,000 which does not fit in an {@code int}. *
* This implementation uses {@link #getMinimum()} and {@link #getMaximum()}. * * @return true if a valid value always fits in an {@code int} */ public boolean isIntValue() { return getMinimum() >= Integer.MIN_VALUE && getMaximum() <= Integer.MAX_VALUE; } /** * Checks if the value is within the valid range. *
* This checks that the value is within the stored range of values. * * @param value the value to check * @return true if the value is valid */ public boolean isValidValue(long value) { return (value >= getMinimum() && value <= getMaximum()); } /** * Checks if the value is within the valid range and that all values * in the range fit in an {@code int}. *
* This method combines {@link #isIntValue()} and {@link #isValidValue(long)}. * * @param value the value to check * @return true if the value is valid and fits in an {@code int} */ public boolean isValidIntValue(long value) { return isIntValue() && isValidValue(value); } /** * Checks that the specified value is valid. *
* This validates that the value is within the valid range of values. * The field is only used to improve the error message. * * @param value the value to check * @param field the field being checked, may be null * @return the value that was passed in * @see #isValidValue(long) */ public long checkValidValue(long value, TemporalField field) { if (isValidValue(value) == false) { throw new DateTimeException(genInvalidFieldMessage(field, value)); } return value; } /** * Checks that the specified value is valid and fits in an {@code int}. *
* This validates that the value is within the valid range of values and that * all valid values are within the bounds of an {@code int}. * The field is only used to improve the error message. * * @param value the value to check * @param field the field being checked, may be null * @return the value that was passed in * @see #isValidIntValue(long) */ public int checkValidIntValue(long value, TemporalField field) { if (isValidIntValue(value) == false) { throw new DateTimeException(genInvalidFieldMessage(field, value)); } return (int) value; } private String genInvalidFieldMessage(TemporalField field, long value) { if (field != null) { return "Invalid value for " + field + " (valid values " + this + "): " + value; } else { return "Invalid value (valid values " + this + "): " + value; } } //----------------------------------------------------------------------- /** * Restore the state of an ValueRange from the stream. * Check that the values are valid. * * @param s the stream to read * @throws InvalidObjectException if * the smallest minimum is greater than the smallest maximum, * or the smallest maximum is greater than the largest maximum * or the largest minimum is greater than the largest maximum * @throws ClassNotFoundException if a class cannot be resolved */ private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException, InvalidObjectException { s.defaultReadObject(); if (minSmallest > minLargest) { throw new InvalidObjectException("Smallest minimum value must be less than largest minimum value"); } if (maxSmallest > maxLargest) { throw new InvalidObjectException("Smallest maximum value must be less than largest maximum value"); } if (minLargest > maxLargest) { throw new InvalidObjectException("Minimum value must be less than maximum value"); } } //----------------------------------------------------------------------- /** * Checks if this range is equal to another range. *
* The comparison is based on the four values, minimum, largest minimum, * smallest maximum and maximum. * Only objects of type {@code ValueRange} are compared, other types return false. * * @param obj the object to check, null returns false * @return true if this is equal to the other range */ @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (obj instanceof ValueRange) { ValueRange other = (ValueRange) obj; return minSmallest == other.minSmallest && minLargest == other.minLargest && maxSmallest == other.maxSmallest && maxLargest == other.maxLargest; } return false; } /** * A hash code for this range. * * @return a suitable hash code */ @Override public int hashCode() { long hash = minSmallest + minLargest << 16 + minLargest >> 48 + maxSmallest << 32 + maxSmallest >> 32 + maxLargest << 48 + maxLargest >> 16; return (int) (hash ^ (hash >>> 32)); } //----------------------------------------------------------------------- /** * Outputs this range as a {@code String}. *
* The format will be '{min}/{largestMin} - {smallestMax}/{max}', * where the largestMin or smallestMax sections may be omitted, together * with associated slash, if they are the same as the min or max. * * @return a string representation of this range, not null */ @Override public String toString() { StringBuilder buf = new StringBuilder(); buf.append(minSmallest); if (minSmallest != minLargest) { buf.append('/').append(minLargest); } buf.append(" - ").append(maxSmallest); if (maxSmallest != maxLargest) { buf.append('/').append(maxLargest); } return buf.toString(); } }