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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
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package org.apache.commons.lang3;

import java.io.Serializable;
import java.util.Comparator;
import java.util.Objects;

/**
 * An immutable range of objects from a minimum to maximum point inclusive.
 *
 * 

The objects need to either be implementations of {@link Comparable} * or you need to supply a {@link Comparator}.

* *

#ThreadSafe# if the objects and comparator are thread-safe.

* * @param The type of range values. * @since 3.0 */ public class Range implements Serializable { @SuppressWarnings({"rawtypes", "unchecked"}) private enum ComparableComparator implements Comparator { INSTANCE; /** * Comparable based compare implementation. * * @param obj1 left-hand side of comparison * @param obj2 right-hand side of comparison * @return negative, 0, positive comparison value */ @Override public int compare(final Object obj1, final Object obj2) { return ((Comparable) obj1).compareTo(obj2); } } /** * Serialization version. * * @see java.io.Serializable */ private static final long serialVersionUID = 1L; /** * Creates a range with the specified minimum and maximum values (both inclusive). * *

The range uses the natural ordering of the elements to determine where * values lie in the range.

* *

The arguments may be passed in the order (min,max) or (max,min). * The getMinimum and getMaximum methods will return the correct values.

* * @param the type of the elements in this range * @param fromInclusive the first value that defines the edge of the range, inclusive * @param toInclusive the second value that defines the edge of the range, inclusive * @return the range object, not null * @throws NullPointerException when fromInclusive is null. * @throws NullPointerException when toInclusive is null. * @throws ClassCastException if the elements are not {@link Comparable} * @deprecated Use {@link #of(Comparable, Comparable)}. */ @Deprecated public static > Range between(final T fromInclusive, final T toInclusive) { return of(fromInclusive, toInclusive, null); } /** * Creates a range with the specified minimum and maximum values (both inclusive). * *

The range uses the specified {@link Comparator} to determine where * values lie in the range.

* *

The arguments may be passed in the order (min,max) or (max,min). * The getMinimum and getMaximum methods will return the correct values.

* * @param the type of the elements in this range * @param fromInclusive the first value that defines the edge of the range, inclusive * @param toInclusive the second value that defines the edge of the range, inclusive * @param comparator the comparator to be used, null for natural ordering * @return the range object, not null * @throws NullPointerException when fromInclusive is null. * @throws NullPointerException when toInclusive is null. * @throws ClassCastException if using natural ordering and the elements are not {@link Comparable} * @deprecated Use {@link #of(Object, Object, Comparator)}. */ @Deprecated public static Range between(final T fromInclusive, final T toInclusive, final Comparator comparator) { return new Range<>(fromInclusive, toInclusive, comparator); } /** * Creates a range using the specified element as both the minimum * and maximum in this range. * *

The range uses the natural ordering of the elements to determine where * values lie in the range.

* * @param the type of the elements in this range * @param element the value to use for this range, not null * @return the range object, not null * @throws NullPointerException if the element is null * @throws ClassCastException if the element is not {@link Comparable} */ public static > Range is(final T element) { return of(element, element, null); } /** * Creates a range using the specified element as both the minimum * and maximum in this range. * *

The range uses the specified {@link Comparator} to determine where * values lie in the range.

* * @param the type of the elements in this range * @param element the value to use for this range, must not be {@code null} * @param comparator the comparator to be used, null for natural ordering * @return the range object, not null * @throws NullPointerException if the element is null * @throws ClassCastException if using natural ordering and the elements are not {@link Comparable} */ public static Range is(final T element, final Comparator comparator) { return of(element, element, comparator); } /** * Creates a range with the specified minimum and maximum values (both inclusive). * *

The range uses the natural ordering of the elements to determine where * values lie in the range.

* *

The arguments may be passed in the order (min,max) or (max,min). * The getMinimum and getMaximum methods will return the correct values.

* * @param the type of the elements in this range * @param fromInclusive the first value that defines the edge of the range, inclusive * @param toInclusive the second value that defines the edge of the range, inclusive * @return the range object, not null * @throws NullPointerException if either element is null * @throws ClassCastException if the elements are not {@link Comparable} * @since 3.13.0 */ public static > Range of(final T fromInclusive, final T toInclusive) { return of(fromInclusive, toInclusive, null); } /** * Creates a range with the specified minimum and maximum values (both inclusive). * *

The range uses the specified {@link Comparator} to determine where * values lie in the range.

* *

The arguments may be passed in the order (min,max) or (max,min). * The getMinimum and getMaximum methods will return the correct values.

* * @param the type of the elements in this range * @param fromInclusive the first value that defines the edge of the range, inclusive * @param toInclusive the second value that defines the edge of the range, inclusive * @param comparator the comparator to be used, null for natural ordering * @return the range object, not null * @throws NullPointerException when fromInclusive is null. * @throws NullPointerException when toInclusive is null. * @throws ClassCastException if using natural ordering and the elements are not {@link Comparable} * @since 3.13.0 */ public static Range of(final T fromInclusive, final T toInclusive, final Comparator comparator) { return new Range<>(fromInclusive, toInclusive, comparator); } /** * The ordering scheme used in this range. */ private final Comparator comparator; /** * Cached output hashCode (class is immutable). */ private transient int hashCode; /** * The maximum value in this range (inclusive). */ private final T maximum; /** * The minimum value in this range (inclusive). */ private final T minimum; /** * Cached output toString (class is immutable). */ private transient String toString; /** * Creates an instance. * * @param element1 the first element, not null * @param element2 the second element, not null * @param comp the comparator to be used, null for natural ordering * @throws NullPointerException when element1 is null. * @throws NullPointerException when element2 is null. */ @SuppressWarnings("unchecked") Range(final T element1, final T element2, final Comparator comp) { Objects.requireNonNull(element1, "element1"); Objects.requireNonNull(element2, "element2"); if (comp == null) { this.comparator = ComparableComparator.INSTANCE; } else { this.comparator = comp; } if (this.comparator.compare(element1, element2) < 1) { this.minimum = element1; this.maximum = element2; } else { this.minimum = element2; this.maximum = element1; } } /** * Checks whether the specified element occurs within this range. * * @param element the element to check for, null returns false * @return true if the specified element occurs within this range */ public boolean contains(final T element) { if (element == null) { return false; } return comparator.compare(element, minimum) > -1 && comparator.compare(element, maximum) < 1; } /** * Checks whether this range contains all the elements of the specified range. * *

This method may fail if the ranges have two different comparators or element types.

* * @param otherRange the range to check, null returns false * @return true if this range contains the specified range * @throws RuntimeException if ranges cannot be compared */ public boolean containsRange(final Range otherRange) { if (otherRange == null) { return false; } return contains(otherRange.minimum) && contains(otherRange.maximum); } /** * Checks where the specified element occurs relative to this range. * *

The API is reminiscent of the Comparable interface returning {@code -1} if * the element is before the range, {@code 0} if contained within the range and * {@code 1} if the element is after the range.

* * @param element the element to check for, not null * @return -1, 0 or +1 depending on the element's location relative to the range * @throws NullPointerException if {@code element} is {@code null} */ public int elementCompareTo(final T element) { // Comparable API says throw NPE on null Objects.requireNonNull(element, "element"); if (isAfter(element)) { return -1; } if (isBefore(element)) { return 1; } return 0; } /** * Compares this range to another object to test if they are equal.. * *

To be equal, the minimum and maximum values must be equal, which * ignores any differences in the comparator.

* * @param obj the reference object with which to compare * @return true if this object is equal */ @Override public boolean equals(final Object obj) { if (obj == this) { return true; } if (obj == null || obj.getClass() != getClass()) { return false; } @SuppressWarnings("unchecked") // OK because we checked the class above final Range range = (Range) obj; return minimum.equals(range.minimum) && maximum.equals(range.maximum); } /** * Fits the given element into this range by returning the given element or, if out of bounds, the range minimum if * below, or the range maximum if above. * *
     * Range<Integer> range = Range.between(16, 64);
     * range.fit(-9) -->  16
     * range.fit(0)  -->  16
     * range.fit(15) -->  16
     * range.fit(16) -->  16
     * range.fit(17) -->  17
     * ...
     * range.fit(63) -->  63
     * range.fit(64) -->  64
     * range.fit(99) -->  64
     * 
* @param element the element to check for, not null * @return the minimum, the element, or the maximum depending on the element's location relative to the range * @throws NullPointerException if {@code element} is {@code null} * @since 3.10 */ public T fit(final T element) { // Comparable API says throw NPE on null Objects.requireNonNull(element, "element"); if (isAfter(element)) { return minimum; } if (isBefore(element)) { return maximum; } return element; } /** * Gets the comparator being used to determine if objects are within the range. * *

Natural ordering uses an internal comparator implementation, thus this * method never returns null. See {@link #isNaturalOrdering()}.

* * @return the comparator being used, not null */ public Comparator getComparator() { return comparator; } /** * Gets the maximum value in this range. * * @return the maximum value in this range, not null */ public T getMaximum() { return maximum; } /** * Gets the minimum value in this range. * * @return the minimum value in this range, not null */ public T getMinimum() { return minimum; } /** * Gets a suitable hash code for the range. * * @return a hash code value for this object */ @Override public int hashCode() { int result = hashCode; if (hashCode == 0) { result = 17; result = 37 * result + getClass().hashCode(); result = 37 * result + minimum.hashCode(); result = 37 * result + maximum.hashCode(); hashCode = result; } return result; } /** * Calculate the intersection of {@code this} and an overlapping Range. * @param other overlapping Range * @return range representing the intersection of {@code this} and {@code other} ({@code this} if equal) * @throws IllegalArgumentException if {@code other} does not overlap {@code this} * @since 3.0.1 */ public Range intersectionWith(final Range other) { if (!this.isOverlappedBy(other)) { throw new IllegalArgumentException(String.format( "Cannot calculate intersection with non-overlapping range %s", other)); } if (this.equals(other)) { return this; } final T min = getComparator().compare(minimum, other.minimum) < 0 ? other.minimum : minimum; final T max = getComparator().compare(maximum, other.maximum) < 0 ? maximum : other.maximum; return of(min, max, getComparator()); } /** * Checks whether this range is after the specified element. * * @param element the element to check for, null returns false * @return true if this range is entirely after the specified element */ public boolean isAfter(final T element) { if (element == null) { return false; } return comparator.compare(element, minimum) < 0; } /** * Checks whether this range is completely after the specified range. * *

This method may fail if the ranges have two different comparators or element types.

* * @param otherRange the range to check, null returns false * @return true if this range is completely after the specified range * @throws RuntimeException if ranges cannot be compared */ public boolean isAfterRange(final Range otherRange) { if (otherRange == null) { return false; } return isAfter(otherRange.maximum); } /** * Checks whether this range is before the specified element. * * @param element the element to check for, null returns false * @return true if this range is entirely before the specified element */ public boolean isBefore(final T element) { if (element == null) { return false; } return comparator.compare(element, maximum) > 0; } /** * Checks whether this range is completely before the specified range. * *

This method may fail if the ranges have two different comparators or element types.

* * @param otherRange the range to check, null returns false * @return true if this range is completely before the specified range * @throws RuntimeException if ranges cannot be compared */ public boolean isBeforeRange(final Range otherRange) { if (otherRange == null) { return false; } return isBefore(otherRange.minimum); } /** * Checks whether this range ends with the specified element. * * @param element the element to check for, null returns false * @return true if the specified element occurs within this range */ public boolean isEndedBy(final T element) { if (element == null) { return false; } return comparator.compare(element, maximum) == 0; } /** * Whether or not the Range is using the natural ordering of the elements. * *

Natural ordering uses an internal comparator implementation, thus this * method is the only way to check if a null comparator was specified.

* * @return true if using natural ordering */ public boolean isNaturalOrdering() { return comparator == ComparableComparator.INSTANCE; } /** * Checks whether this range is overlapped by the specified range. * *

Two ranges overlap if there is at least one element in common.

* *

This method may fail if the ranges have two different comparators or element types.

* * @param otherRange the range to test, null returns false * @return true if the specified range overlaps with this * range; otherwise, {@code false} * @throws RuntimeException if ranges cannot be compared */ public boolean isOverlappedBy(final Range otherRange) { if (otherRange == null) { return false; } return otherRange.contains(minimum) || otherRange.contains(maximum) || contains(otherRange.minimum); } /** * Checks whether this range starts with the specified element. * * @param element the element to check for, null returns false * @return true if the specified element occurs within this range */ public boolean isStartedBy(final T element) { if (element == null) { return false; } return comparator.compare(element, minimum) == 0; } /** * Gets the range as a {@link String}. * *

The format of the String is '[min..max]'.

* * @return the {@link String} representation of this range */ @Override public String toString() { if (toString == null) { toString = "[" + minimum + ".." + maximum + "]"; } return toString; } /** * Formats the receiver using the given format. * *

This uses {@link java.util.Formattable} to perform the formatting. Three variables may * be used to embed the minimum, maximum and comparator. * Use {@code %1$s} for the minimum element, {@code %2$s} for the maximum element * and {@code %3$s} for the comparator. * The default format used by {@code toString()} is {@code [%1$s..%2$s]}.

* * @param format the format string, optionally containing {@code %1$s}, {@code %2$s} and {@code %3$s}, not null * @return the formatted string, not null */ public String toString(final String format) { return String.format(format, minimum, maximum, comparator); } }




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