    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017    package org.apache.commons.lang.math;
    018
    019    import java.io.Serializable;
    020
    021    /**
    022     * <p><code>FloatRange</code> represents an inclusive range of <code>float</code>s.</p>
    023     *
    024     * @author Apache Software Foundation
    025     * @since 2.0
    026     * @version $Id: FloatRange.java 905636 2010-02-02 14:03:32Z niallp $
    027     */
    028    public final class FloatRange extends Range implements Serializable {
    029
    030        /**
    031         * Required for serialization support.
    032         *
    033         * @see java.io.Serializable
    034         */
    035        private static final long serialVersionUID = 71849363892750L;
    036
    037        /**
    038         * The minimum number in this range (inclusive).
    039         */
    040        private final float min;
    041        /**
    042         * The maximum number in this range (inclusive).
    043         */
    044        private final float max;
    045
    046        /**
    047         * Cached output minObject (class is immutable).
    048         */
    049        private transient Float minObject = null;
    050        /**
    051         * Cached output maxObject (class is immutable).
    052         */
    053        private transient Float maxObject = null;
    054        /**
    055         * Cached output hashCode (class is immutable).
    056         */
    057        private transient int hashCode = 0;
    058        /**
    059         * Cached output toString (class is immutable).
    060         */
    061        private transient String toString = null;
    062
    063        /**
    064         * <p>Constructs a new <code>FloatRange</code> using the specified
    065         * number as both the minimum and maximum in this range.</p>
    066         *
    067         * @param number  the number to use for this range
    068         * @throws IllegalArgumentException if the number is <code>NaN</code>
    069         */
    070        public FloatRange(float number) {
    071            super();
    072            if (Float.isNaN(number)) {
    073                throw new IllegalArgumentException("The number must not be NaN");
    074            }
    075            this.min = number;
    076            this.max = number;
    077        }
    078
    079        /**
    080         * <p>Constructs a new <code>FloatRange</code> using the specified
    081         * number as both the minimum and maximum in this range.</p>
    082         *
    083         * @param number  the number to use for this range, must not
    084         *  be <code>null</code>
    085         * @throws IllegalArgumentException if the number is <code>null</code>
    086         * @throws IllegalArgumentException if the number is <code>NaN</code>
    087         */
    088        public FloatRange(Number number) {
    089            super();
    090            if (number == null) {
    091                throw new IllegalArgumentException("The number must not be null");
    092            }
    093            this.min = number.floatValue();
    094            this.max = number.floatValue();
    095            if (Float.isNaN(min) || Float.isNaN(max)) {
    096                throw new IllegalArgumentException("The number must not be NaN");
    097            }
    098            if (number instanceof Float) {
    099                this.minObject = (Float) number;
    100                this.maxObject = (Float) number;
    101            }
    102        }
    103
    104        /**
    105         * <p>Constructs a new <code>FloatRange</code> with the specified
    106         * minimum and maximum numbers (both inclusive).</p>
    107         *
    108         * <p>The arguments may be passed in the order (min,max) or (max,min). The
    109         * getMinimum and getMaximum methods will return the correct values.</p>
    110         *
    111         * @param number1  first number that defines the edge of the range, inclusive
    112         * @param number2  second number that defines the edge of the range, inclusive
    113         * @throws IllegalArgumentException if either number is <code>NaN</code>
    114         */
    115        public FloatRange(float number1, float number2) {
    116            super();
    117            if (Float.isNaN(number1) || Float.isNaN(number2)) {
    118                throw new IllegalArgumentException("The numbers must not be NaN");
    119            }
    120            if (number2 < number1) {
    121                this.min = number2;
    122                this.max = number1;
    123            } else {
    124                this.min = number1;
    125                this.max = number2;
    126            }
    127        }
    128
    129        /**
    130         * <p>Constructs a new <code>FloatRange</code> with the specified
    131         * minimum and maximum numbers (both inclusive).</p>
    132         *
    133         * <p>The arguments may be passed in the order (min,max) or (max,min). The
    134         * getMinimum and getMaximum methods will return the correct values.</p>
    135         *
    136         * @param number1  first number that defines the edge of the range, inclusive
    137         * @param number2  second number that defines the edge of the range, inclusive
    138         * @throws IllegalArgumentException if either number is <code>null</code>
    139         * @throws IllegalArgumentException if either number is <code>NaN</code>
    140         */
    141        public FloatRange(Number number1, Number number2) {
    142            super();
    143            if (number1 == null || number2 == null) {
    144                throw new IllegalArgumentException("The numbers must not be null");
    145            }
    146            float number1val = number1.floatValue();
    147            float number2val = number2.floatValue();
    148            if (Float.isNaN(number1val) || Float.isNaN(number2val)) {
    149                throw new IllegalArgumentException("The numbers must not be NaN");
    150            }
    151            if (number2val < number1val) {
    152                this.min = number2val;
    153                this.max = number1val;
    154                if (number2 instanceof Float) {
    155                    this.minObject = (Float) number2;
    156                }
    157                if (number1 instanceof Float) {
    158                    this.maxObject = (Float) number1;
    159                }
    160            } else {
    161                this.min = number1val;
    162                this.max = number2val;
    163                if (number1 instanceof Float) {
    164                    this.minObject = (Float) number1;
    165                }
    166                if (number2 instanceof Float) {
    167                    this.maxObject = (Float) number2;
    168                }
    169            }
    170        }
    171
    172        // Accessors
    173        //--------------------------------------------------------------------
    174
    175        /**
    176         * <p>Returns the minimum number in this range.</p>
    177         *
    178         * @return the minimum number in this range
    179         */
    180        public Number getMinimumNumber() {
    181            if (minObject == null) {
    182                minObject = new Float(min);
    183            }
    184            return minObject;
    185        }
    186
    187        /**
    188         * <p>Gets the minimum number in this range as a <code>long</code>.</p>
    189         *
    190         * <p>This conversion can lose information for large values or decimals.</p>
    191         *
    192         * @return the minimum number in this range
    193         */
    194        public long getMinimumLong() {
    195            return (long) min;
    196        }
    197
    198        /**
    199         * <p>Gets the minimum number in this range as a <code>int</code>.</p>
    200         *
    201         * <p>This conversion can lose information for large values or decimals.</p>
    202         *
    203         * @return the minimum number in this range
    204         */
    205        public int getMinimumInteger() {
    206            return (int) min;
    207        }
    208
    209        /**
    210         * <p>Gets the minimum number in this range as a <code>double</code>.</p>
    211         *
    212         * @return the minimum number in this range
    213         */
    214        public double getMinimumDouble() {
    215            return min;
    216        }
    217
    218        /**
    219         * <p>Gets the minimum number in this range as a <code>float</code>.</p>
    220         *
    221         * @return the minimum number in this range
    222         */
    223        public float getMinimumFloat() {
    224            return min;
    225        }
    226
    227        /**
    228         * <p>Returns the maximum number in this range.</p>
    229         *
    230         * @return the maximum number in this range
    231         */
    232        public Number getMaximumNumber() {
    233            if (maxObject == null) {
    234                maxObject = new Float(max);
    235            }
    236            return maxObject;
    237        }
    238
    239        /**
    240         * <p>Gets the maximum number in this range as a <code>long</code>.</p>
    241         *
    242         * <p>This conversion can lose information for large values or decimals.</p>
    243         *
    244         * @return the maximum number in this range
    245         */
    246        public long getMaximumLong() {
    247            return (long) max;
    248        }
    249
    250        /**
    251         * <p>Gets the maximum number in this range as a <code>int</code>.</p>
    252         *
    253         * <p>This conversion can lose information for large values or decimals.</p>
    254         *
    255         * @return the maximum number in this range
    256         */
    257        public int getMaximumInteger() {
    258            return (int) max;
    259        }
    260
    261        /**
    262         * <p>Gets the maximum number in this range as a <code>double</code>.</p>
    263         *
    264         * @return the maximum number in this range
    265         */
    266        public double getMaximumDouble() {
    267            return max;
    268        }
    269
    270        /**
    271         * <p>Gets the maximum number in this range as a <code>float</code>.</p>
    272         *
    273         * @return the maximum number in this range
    274         */
    275        public float getMaximumFloat() {
    276            return max;
    277        }
    278
    279        // Tests
    280        //--------------------------------------------------------------------
    281
    282        /**
    283         * <p>Tests whether the specified <code>number</code> occurs within
    284         * this range using <code>float</code> comparison.</p>
    285         *
    286         * <p><code>null</code> is handled and returns <code>false</code>.</p>
    287         *
    288         * @param number  the number to test, may be <code>null</code>
    289         * @return <code>true</code> if the specified number occurs within this range
    290         */
    291        public boolean containsNumber(Number number) {
    292            if (number == null) {
    293                return false;
    294            }
    295            return containsFloat(number.floatValue());
    296        }
    297
    298        /**
    299         * <p>Tests whether the specified <code>float</code> occurs within
    300         * this range using <code>float</code> comparison.</p>
    301         *
    302         * <p>This implementation overrides the superclass for performance as it is
    303         * the most common case.</p>
    304         *
    305         * @param value  the float to test
    306         * @return <code>true</code> if the specified number occurs within this
    307         *  range by <code>float</code> comparison
    308         */
    309        public boolean containsFloat(float value) {
    310            return value >= min && value <= max;
    311        }
    312
    313        // Range tests
    314        //--------------------------------------------------------------------
    315
    316        /**
    317         * <p>Tests whether the specified range occurs entirely within this range
    318         * using <code>float</code> comparison.</p>
    319         *
    320         * <p><code>null</code> is handled and returns <code>false</code>.</p>
    321         *
    322         * @param range  the range to test, may be <code>null</code>
    323         * @return <code>true</code> if the specified range occurs entirely within this range
    324         * @throws IllegalArgumentException if the range is not of this type
    325         */
    326        public boolean containsRange(Range range) {
    327            if (range == null) {
    328                return false;
    329            }
    330            return containsFloat(range.getMinimumFloat()) &&
    331                   containsFloat(range.getMaximumFloat());
    332        }
    333
    334        /**
    335         * <p>Tests whether the specified range overlaps with this range
    336         * using <code>float</code> comparison.</p>
    337         *
    338         * <p><code>null</code> is handled and returns <code>false</code>.</p>
    339         *
    340         * @param range  the range to test, may be <code>null</code>
    341         * @return <code>true</code> if the specified range overlaps with this range
    342         */
    343        public boolean overlapsRange(Range range) {
    344            if (range == null) {
    345                return false;
    346            }
    347            return range.containsFloat(min) ||
    348                   range.containsFloat(max) ||
    349                   containsFloat(range.getMinimumFloat());
    350        }
    351
    352        // Basics
    353        //--------------------------------------------------------------------
    354
    355        /**
    356         * <p>Compares this range to another object to test if they are equal.</p>.
    357         *
    358         * <p>To be equal, the class, minimum and maximum must be equal.</p>
    359         *
    360         * @param obj the reference object with which to compare
    361         * @return <code>true</code> if this object is equal
    362         */
    363        public boolean equals(Object obj) {
    364            if (obj == this) {
    365                return true;
    366            }
    367            if (obj instanceof FloatRange == false) {
    368                return false;
    369            }
    370            FloatRange range = (FloatRange) obj;
    371            return (Float.floatToIntBits(min) == Float.floatToIntBits(range.min) &&
    372                    Float.floatToIntBits(max) == Float.floatToIntBits(range.max));
    373        }
    374
    375        /**
    376         * <p>Gets a hashCode for the range.</p>
    377         *
    378         * @return a hash code value for this object
    379         */
    380        public int hashCode() {
    381            if (hashCode == 0) {
    382                hashCode = 17;
    383                hashCode = 37 * hashCode + getClass().hashCode();
    384                hashCode = 37 * hashCode + Float.floatToIntBits(min);
    385                hashCode = 37 * hashCode + Float.floatToIntBits(max);
    386            }
    387            return hashCode;
    388        }
    389
    390        /**
    391         * <p>Gets the range as a <code>String</code>.</p>
    392         *
    393         * <p>The format of the String is 'Range[<i>min</i>,<i>max</i>]'.</p>
    394         *
    395         * @return the <code>String</code> representation of this range
    396         */
    397        public String toString() {
    398            if (toString == null) {
    399                StringBuffer buf = new StringBuffer(32);
    400                buf.append("Range[");
    401                buf.append(min);
    402                buf.append(',');
    403                buf.append(max);
    404                buf.append(']');
    405                toString = buf.toString();
    406            }
    407            return toString;
    408        }
    409
    410    }