    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 */
    017package org.apache.commons.lang3;
    018
    019import org.apache.commons.lang3.math.NumberUtils;
    020
    021/**
    022 * <p>Operations on boolean primitives and Boolean objects.</p>
    023 *
    024 * <p>This class tries to handle {@code null} input gracefully.
    025 * An exception will not be thrown for a {@code null} input.
    026 * Each method documents its behavior in more detail.</p>
    027 *
    028 * <p>#ThreadSafe#</p>
    029 * @since 2.0
    030 */
    031public class BooleanUtils {
    032    /**
    033     * The false String {@code "false"}.
    034     *
    035     * @since 3.12.0
    036     */
    037    public static final String FALSE = "false";
    038
    039    /**
    040     * The no String {@code "no"}.
    041     *
    042     * @since 3.12.0
    043     */
    044    public static final String NO = "no";
    045
    046    /**
    047     * The off String {@code "off"}.
    048     *
    049     * @since 3.12.0
    050     */
    051    public static final String OFF = "off";
    052
    053    /**
    054     * The on String {@code "on"}.
    055     *
    056     * @since 3.12.0
    057     */
    058    public static final String ON = "on";
    059
    060    /**
    061     * The true String {@code "true"}.
    062     *
    063     * @since 3.12.0
    064     */
    065    public static final String TRUE = "true";
    066
    067    /**
    068     * The yes String {@code "yes"}.
    069     *
    070     * @since 3.12.0
    071     */
    072    public static final String YES = "yes";
    073
    074    /**
    075     * <p>Performs an 'and' operation on a set of booleans.</p>
    076     *
    077     * <pre>
    078     *   BooleanUtils.and(true, true)         = true
    079     *   BooleanUtils.and(false, false)       = false
    080     *   BooleanUtils.and(true, false)        = false
    081     *   BooleanUtils.and(true, true, false)  = false
    082     *   BooleanUtils.and(true, true, true)   = true
    083     * </pre>
    084     *
    085     * @param array  an array of {@code boolean}s
    086     * @return the result of the logical 'and' operation. That is {@code false}
    087     * if any of the parameters is {@code false} and {@code true} otherwise.
    088     * @throws NullPointerException if {@code array} is {@code null}
    089     * @throws IllegalArgumentException if {@code array} is empty.
    090     * @since 3.0.1
    091     */
    092    public static boolean and(final boolean... array) {
    093        ObjectUtils.requireNonEmpty(array, "array");
    094        for (final boolean element : array) {
    095            if (!element) {
    096                return false;
    097            }
    098        }
    099        return true;
    100    }
    101
    102    /**
    103     * <p>Performs an 'and' operation on an array of Booleans.</p>
    104     *
    105     * <pre>
    106     *   BooleanUtils.and(Boolean.TRUE, Boolean.TRUE)                 = Boolean.TRUE
    107     *   BooleanUtils.and(Boolean.FALSE, Boolean.FALSE)               = Boolean.FALSE
    108     *   BooleanUtils.and(Boolean.TRUE, Boolean.FALSE)                = Boolean.FALSE
    109     *   BooleanUtils.and(Boolean.TRUE, Boolean.TRUE, Boolean.TRUE)   = Boolean.TRUE
    110     *   BooleanUtils.and(Boolean.FALSE, Boolean.FALSE, Boolean.TRUE) = Boolean.FALSE
    111     *   BooleanUtils.and(Boolean.TRUE, Boolean.FALSE, Boolean.TRUE)  = Boolean.FALSE
    112     * </pre>
    113     *
    114     * @param array  an array of {@code Boolean}s
    115     * @return the result of the logical 'and' operation. That is {@code false}
    116     * if any of the parameters is {@code false} and {@code true} otherwise.
    117     * @throws NullPointerException if {@code array} is {@code null}
    118     * @throws IllegalArgumentException if {@code array} is empty.
    119     * @throws IllegalArgumentException if {@code array} contains a {@code null}
    120     * @since 3.0.1
    121     */
    122    public static Boolean and(final Boolean... array) {
    123        ObjectUtils.requireNonEmpty(array, "array");
    124        try {
    125            final boolean[] primitive = ArrayUtils.toPrimitive(array);
    126            return and(primitive) ? Boolean.TRUE : Boolean.FALSE;
    127        } catch (final NullPointerException ex) {
    128            throw new IllegalArgumentException("The array must not contain any null elements");
    129        }
    130    }
    131
    132    /**
    133     * Returns a new array of possible values (like an enum would).
    134     * @return a new array of possible values (like an enum would).
    135     * @since 3.12.0
    136     */
    137    public static Boolean[] booleanValues() {
    138        return new Boolean[] {Boolean.FALSE, Boolean.TRUE};
    139    }
    140
    141    /**
    142     * <p>Compares two {@code boolean} values. This is the same functionality as provided in Java 7.</p>
    143     *
    144     * @param x the first {@code boolean} to compare
    145     * @param y the second {@code boolean} to compare
    146     * @return the value {@code 0} if {@code x == y};
    147     *         a value less than {@code 0} if {@code !x && y}; and
    148     *         a value greater than {@code 0} if {@code x && !y}
    149     * @since 3.4
    150     */
    151    public static int compare(final boolean x, final boolean y) {
    152        if (x == y) {
    153            return 0;
    154        }
    155        return x ? 1 : -1;
    156    }
    157
    158    /**
    159     * <p>Checks if a {@code Boolean} value is {@code false},
    160     * handling {@code null} by returning {@code false}.</p>
    161     *
    162     * <pre>
    163     *   BooleanUtils.isFalse(Boolean.TRUE)  = false
    164     *   BooleanUtils.isFalse(Boolean.FALSE) = true
    165     *   BooleanUtils.isFalse(null)          = false
    166     * </pre>
    167     *
    168     * @param bool  the boolean to check, null returns {@code false}
    169     * @return {@code true} only if the input is non-{@code null} and {@code false}
    170     * @since 2.1
    171     */
    172    public static boolean isFalse(final Boolean bool) {
    173        return Boolean.FALSE.equals(bool);
    174    }
    175
    176    /**
    177     * <p>Checks if a {@code Boolean} value is <i>not</i> {@code false},
    178     * handling {@code null} by returning {@code true}.</p>
    179     *
    180     * <pre>
    181     *   BooleanUtils.isNotFalse(Boolean.TRUE)  = true
    182     *   BooleanUtils.isNotFalse(Boolean.FALSE) = false
    183     *   BooleanUtils.isNotFalse(null)          = true
    184     * </pre>
    185     *
    186     * @param bool  the boolean to check, null returns {@code true}
    187     * @return {@code true} if the input is {@code null} or {@code true}
    188     * @since 2.3
    189     */
    190    public static boolean isNotFalse(final Boolean bool) {
    191        return !isFalse(bool);
    192    }
    193
    194    /**
    195     * <p>Checks if a {@code Boolean} value is <i>not</i> {@code true},
    196     * handling {@code null} by returning {@code true}.</p>
    197     *
    198     * <pre>
    199     *   BooleanUtils.isNotTrue(Boolean.TRUE)  = false
    200     *   BooleanUtils.isNotTrue(Boolean.FALSE) = true
    201     *   BooleanUtils.isNotTrue(null)          = true
    202     * </pre>
    203     *
    204     * @param bool  the boolean to check, null returns {@code true}
    205     * @return {@code true} if the input is null or false
    206     * @since 2.3
    207     */
    208    public static boolean isNotTrue(final Boolean bool) {
    209        return !isTrue(bool);
    210    }
    211
    212    /**
    213     * <p>Checks if a {@code Boolean} value is {@code true},
    214     * handling {@code null} by returning {@code false}.</p>
    215     *
    216     * <pre>
    217     *   BooleanUtils.isTrue(Boolean.TRUE)  = true
    218     *   BooleanUtils.isTrue(Boolean.FALSE) = false
    219     *   BooleanUtils.isTrue(null)          = false
    220     * </pre>
    221     *
    222     * @param bool the boolean to check, {@code null} returns {@code false}
    223     * @return {@code true} only if the input is non-null and true
    224     * @since 2.1
    225     */
    226    public static boolean isTrue(final Boolean bool) {
    227        return Boolean.TRUE.equals(bool);
    228    }
    229
    230    /**
    231     * <p>Negates the specified boolean.</p>
    232     *
    233     * <p>If {@code null} is passed in, {@code null} will be returned.</p>
    234     *
    235     * <p>NOTE: This returns {@code null} and will throw a {@code NullPointerException}
    236     * if unboxed to a boolean. </p>
    237     *
    238     * <pre>
    239     *   BooleanUtils.negate(Boolean.TRUE)  = Boolean.FALSE;
    240     *   BooleanUtils.negate(Boolean.FALSE) = Boolean.TRUE;
    241     *   BooleanUtils.negate(null)          = null;
    242     * </pre>
    243     *
    244     * @param bool  the Boolean to negate, may be null
    245     * @return the negated Boolean, or {@code null} if {@code null} input
    246     */
    247    public static Boolean negate(final Boolean bool) {
    248        if (bool == null) {
    249            return null;
    250        }
    251        return bool.booleanValue() ? Boolean.FALSE : Boolean.TRUE;
    252    }
    253    /**
    254     * <p>Performs an 'or' operation on a set of booleans.</p>
    255     *
    256     * <pre>
    257     *   BooleanUtils.or(true, true)          = true
    258     *   BooleanUtils.or(false, false)        = false
    259     *   BooleanUtils.or(true, false)         = true
    260     *   BooleanUtils.or(true, true, false)   = true
    261     *   BooleanUtils.or(true, true, true)    = true
    262     *   BooleanUtils.or(false, false, false) = false
    263     * </pre>
    264     *
    265     * @param array  an array of {@code boolean}s
    266     * @return {@code true} if any of the arguments is {@code true}, and it returns {@code false} otherwise.
    267     * @throws NullPointerException if {@code array} is {@code null}
    268     * @throws IllegalArgumentException if {@code array} is empty.
    269     * @since 3.0.1
    270     */
    271    public static boolean or(final boolean... array) {
    272        ObjectUtils.requireNonEmpty(array, "array");
    273        for (final boolean element : array) {
    274            if (element) {
    275                return true;
    276            }
    277        }
    278        return false;
    279    }
    280
    281    /**
    282     * <p>Performs an 'or' operation on an array of Booleans.</p>
    283     *
    284     * <pre>
    285     *   BooleanUtils.or(Boolean.TRUE, Boolean.TRUE)                  = Boolean.TRUE
    286     *   BooleanUtils.or(Boolean.FALSE, Boolean.FALSE)                = Boolean.FALSE
    287     *   BooleanUtils.or(Boolean.TRUE, Boolean.FALSE)                 = Boolean.TRUE
    288     *   BooleanUtils.or(Boolean.TRUE, Boolean.TRUE, Boolean.TRUE)    = Boolean.TRUE
    289     *   BooleanUtils.or(Boolean.FALSE, Boolean.FALSE, Boolean.TRUE)  = Boolean.TRUE
    290     *   BooleanUtils.or(Boolean.TRUE, Boolean.FALSE, Boolean.TRUE)   = Boolean.TRUE
    291     *   BooleanUtils.or(Boolean.FALSE, Boolean.FALSE, Boolean.FALSE) = Boolean.FALSE
    292     * </pre>
    293     *
    294     * @param array  an array of {@code Boolean}s
    295     * @return {@code true} if any of the arguments is {@code true}, and it returns {@code false} otherwise.
    296     * @throws NullPointerException if {@code array} is {@code null}
    297     * @throws IllegalArgumentException if {@code array} is empty.
    298     * @throws IllegalArgumentException if {@code array} contains a {@code null}
    299     * @since 3.0.1
    300     */
    301    public static Boolean or(final Boolean... array) {
    302        ObjectUtils.requireNonEmpty(array, "array");
    303        try {
    304            final boolean[] primitive = ArrayUtils.toPrimitive(array);
    305            return or(primitive) ? Boolean.TRUE : Boolean.FALSE;
    306        } catch (final NullPointerException ex) {
    307            throw new IllegalArgumentException("The array must not contain any null elements");
    308        }
    309    }
    310
    311    /**
    312     * Returns a new array of possible values (like an enum would).
    313     * @return a new array of possible values (like an enum would).
    314     * @since 3.12.0
    315     */
    316    public static boolean[] primitiveValues() {
    317        return new boolean[] {false, true};
    318    }
    319
    320    /**
    321     * <p>Converts a Boolean to a boolean handling {@code null}
    322     * by returning {@code false}.</p>
    323     *
    324     * <pre>
    325     *   BooleanUtils.toBoolean(Boolean.TRUE)  = true
    326     *   BooleanUtils.toBoolean(Boolean.FALSE) = false
    327     *   BooleanUtils.toBoolean(null)          = false
    328     * </pre>
    329     *
    330     * @param bool  the boolean to convert
    331     * @return {@code true} or {@code false}, {@code null} returns {@code false}
    332     */
    333    public static boolean toBoolean(final Boolean bool) {
    334        return bool != null && bool.booleanValue();
    335    }
    336
    337    /**
    338     * <p>Converts an int to a boolean using the convention that {@code zero}
    339     * is {@code false}, everything else is {@code true}.</p>
    340     *
    341     * <pre>
    342     *   BooleanUtils.toBoolean(0) = false
    343     *   BooleanUtils.toBoolean(1) = true
    344     *   BooleanUtils.toBoolean(2) = true
    345     * </pre>
    346     *
    347     * @param value  the int to convert
    348     * @return {@code true} if non-zero, {@code false}
    349     *  if zero
    350     */
    351    public static boolean toBoolean(final int value) {
    352        return value != 0;
    353    }
    354
    355    /**
    356     * <p>Converts an int to a boolean specifying the conversion values.</p>
    357     *
    358     * <p>If the {@code trueValue} and {@code falseValue} are the same number then
    359     * the return value will be {@code true} in case {@code value} matches it.</p>
    360     *
    361     * <pre>
    362     *   BooleanUtils.toBoolean(0, 1, 0) = false
    363     *   BooleanUtils.toBoolean(1, 1, 0) = true
    364     *   BooleanUtils.toBoolean(1, 1, 1) = true
    365     *   BooleanUtils.toBoolean(2, 1, 2) = false
    366     *   BooleanUtils.toBoolean(2, 2, 0) = true
    367     * </pre>
    368     *
    369     * @param value  the {@code Integer} to convert
    370     * @param trueValue  the value to match for {@code true}
    371     * @param falseValue  the value to match for {@code false}
    372     * @return {@code true} or {@code false}
    373     * @throws IllegalArgumentException if {@code value} does not match neither
    374     * {@code trueValue} no {@code falseValue}
    375     */
    376    public static boolean toBoolean(final int value, final int trueValue, final int falseValue) {
    377        if (value == trueValue) {
    378            return true;
    379        }
    380        if (value == falseValue) {
    381            return false;
    382        }
    383        throw new IllegalArgumentException("The Integer did not match either specified value");
    384    }
    385
    386    /**
    387     * <p>Converts an Integer to a boolean specifying the conversion values.</p>
    388     *
    389     * <pre>
    390     *   BooleanUtils.toBoolean(Integer.valueOf(0), Integer.valueOf(1), Integer.valueOf(0)) = false
    391     *   BooleanUtils.toBoolean(Integer.valueOf(1), Integer.valueOf(1), Integer.valueOf(0)) = true
    392     *   BooleanUtils.toBoolean(Integer.valueOf(2), Integer.valueOf(1), Integer.valueOf(2)) = false
    393     *   BooleanUtils.toBoolean(Integer.valueOf(2), Integer.valueOf(2), Integer.valueOf(0)) = true
    394     *   BooleanUtils.toBoolean(null, null, Integer.valueOf(0))                     = true
    395     * </pre>
    396     *
    397     * @param value  the Integer to convert
    398     * @param trueValue  the value to match for {@code true}, may be {@code null}
    399     * @param falseValue  the value to match for {@code false}, may be {@code null}
    400     * @return {@code true} or {@code false}
    401     * @throws IllegalArgumentException if no match
    402     */
    403    public static boolean toBoolean(final Integer value, final Integer trueValue, final Integer falseValue) {
    404        if (value == null) {
    405            if (trueValue == null) {
    406                return true;
    407            }
    408            if (falseValue == null) {
    409                return false;
    410            }
    411        } else if (value.equals(trueValue)) {
    412            return true;
    413        } else if (value.equals(falseValue)) {
    414            return false;
    415        }
    416        throw new IllegalArgumentException("The Integer did not match either specified value");
    417    }
    418
    419    /**
    420     * <p>Converts a String to a boolean (optimised for performance).</p>
    421     *
    422     * <p>{@code 'true'}, {@code 'on'}, {@code 'y'}, {@code 't'} or {@code 'yes'}
    423     * (case insensitive) will return {@code true}. Otherwise,
    424     * {@code false} is returned.</p>
    425     *
    426     * <p>This method performs 4 times faster (JDK1.4) than
    427     * {@code Boolean.valueOf(String)}. However, this method accepts
    428     * 'on' and 'yes', 't', 'y' as true values.
    429     *
    430     * <pre>
    431     *   BooleanUtils.toBoolean(null)    = false
    432     *   BooleanUtils.toBoolean("true")  = true
    433     *   BooleanUtils.toBoolean("TRUE")  = true
    434     *   BooleanUtils.toBoolean("tRUe")  = true
    435     *   BooleanUtils.toBoolean("on")    = true
    436     *   BooleanUtils.toBoolean("yes")   = true
    437     *   BooleanUtils.toBoolean("false") = false
    438     *   BooleanUtils.toBoolean("x gti") = false
    439     *   BooleanUtils.toBoolean("y") = true
    440     *   BooleanUtils.toBoolean("n") = false
    441     *   BooleanUtils.toBoolean("t") = true
    442     *   BooleanUtils.toBoolean("f") = false
    443     * </pre>
    444     *
    445     * @param str  the String to check
    446     * @return the boolean value of the string, {@code false} if no match or the String is null
    447     */
    448    public static boolean toBoolean(final String str) {
    449        return toBooleanObject(str) == Boolean.TRUE;
    450    }
    451
    452    /**
    453     * <p>Converts a String to a Boolean throwing an exception if no match found.</p>
    454     *
    455     * <pre>
    456     *   BooleanUtils.toBoolean("true", "true", "false")  = true
    457     *   BooleanUtils.toBoolean("false", "true", "false") = false
    458     * </pre>
    459     *
    460     * @param str  the String to check
    461     * @param trueString  the String to match for {@code true} (case sensitive), may be {@code null}
    462     * @param falseString  the String to match for {@code false} (case sensitive), may be {@code null}
    463     * @return the boolean value of the string
    464     * @throws IllegalArgumentException if the String doesn't match
    465     */
    466    public static boolean toBoolean(final String str, final String trueString, final String falseString) {
    467        if (str == trueString) {
    468            return true;
    469        } else if (str == falseString) {
    470            return false;
    471        } else if (str != null) {
    472            if (str.equals(trueString)) {
    473                return true;
    474            } else if (str.equals(falseString)) {
    475                return false;
    476            }
    477        }
    478        throw new IllegalArgumentException("The String did not match either specified value");
    479    }
    480
    481    /**
    482     * <p>Converts a Boolean to a boolean handling {@code null}.</p>
    483     *
    484     * <pre>
    485     *   BooleanUtils.toBooleanDefaultIfNull(Boolean.TRUE, false)  = true
    486     *   BooleanUtils.toBooleanDefaultIfNull(Boolean.TRUE, true)   = true
    487     *   BooleanUtils.toBooleanDefaultIfNull(Boolean.FALSE, true)  = false
    488     *   BooleanUtils.toBooleanDefaultIfNull(Boolean.FALSE, false) = false
    489     *   BooleanUtils.toBooleanDefaultIfNull(null, true)           = true
    490     *   BooleanUtils.toBooleanDefaultIfNull(null, false)          = false
    491     * </pre>
    492     *
    493     * @param bool  the boolean object to convert to primitive
    494     * @param valueIfNull  the boolean value to return if the parameter {@code bool} is {@code null}
    495     * @return {@code true} or {@code false}
    496     */
    497    public static boolean toBooleanDefaultIfNull(final Boolean bool, final boolean valueIfNull) {
    498        if (bool == null) {
    499            return valueIfNull;
    500        }
    501        return bool.booleanValue();
    502    }
    503
    504    /**
    505     * <p>Converts an int to a Boolean using the convention that {@code zero}
    506     * is {@code false}, everything else is {@code true}.</p>
    507     *
    508     * <pre>
    509     *   BooleanUtils.toBoolean(0) = Boolean.FALSE
    510     *   BooleanUtils.toBoolean(1) = Boolean.TRUE
    511     *   BooleanUtils.toBoolean(2) = Boolean.TRUE
    512     * </pre>
    513     *
    514     * @param value  the int to convert
    515     * @return Boolean.TRUE if non-zero, Boolean.FALSE if zero,
    516     *  {@code null} if {@code null}
    517     */
    518    public static Boolean toBooleanObject(final int value) {
    519        return value == 0 ? Boolean.FALSE : Boolean.TRUE;
    520    }
    521
    522    /**
    523     * <p>Converts an int to a Boolean specifying the conversion values.</p>
    524     *
    525     * <p>NOTE: This method may return {@code null} and may throw a {@code NullPointerException}
    526     * if unboxed to a {@code boolean}.</p>
    527     *
    528     * <p>The checks are done first for the {@code trueValue}, then for the {@code falseValue} and
    529     * finally for the {@code nullValue}.</p>
    530     *
    531     * <pre>
    532     *   BooleanUtils.toBooleanObject(0, 0, 2, 3) = Boolean.TRUE
    533     *   BooleanUtils.toBooleanObject(0, 0, 0, 3) = Boolean.TRUE
    534     *   BooleanUtils.toBooleanObject(0, 0, 0, 0) = Boolean.TRUE
    535     *   BooleanUtils.toBooleanObject(2, 1, 2, 3) = Boolean.FALSE
    536     *   BooleanUtils.toBooleanObject(2, 1, 2, 2) = Boolean.FALSE
    537     *   BooleanUtils.toBooleanObject(3, 1, 2, 3) = null
    538     * </pre>
    539     *
    540     * @param value  the Integer to convert
    541     * @param trueValue  the value to match for {@code true}
    542     * @param falseValue  the value to match for {@code false}
    543     * @param nullValue  the value to to match for {@code null}
    544     * @return Boolean.TRUE, Boolean.FALSE, or {@code null}
    545     * @throws IllegalArgumentException if no match
    546     */
    547    public static Boolean toBooleanObject(final int value, final int trueValue, final int falseValue, final int nullValue) {
    548        if (value == trueValue) {
    549            return Boolean.TRUE;
    550        }
    551        if (value == falseValue) {
    552            return Boolean.FALSE;
    553        }
    554        if (value == nullValue) {
    555            return null;
    556        }
    557        throw new IllegalArgumentException("The Integer did not match any specified value");
    558    }
    559
    560    /**
    561     * <p>Converts an Integer to a Boolean using the convention that {@code zero}
    562     * is {@code false}, every other numeric value is {@code true}.</p>
    563     *
    564     * <p>{@code null} will be converted to {@code null}.</p>
    565     *
    566     * <p>NOTE: This method may return {@code null} and may throw a {@code NullPointerException}
    567     * if unboxed to a {@code boolean}.</p>
    568     *
    569     * <pre>
    570     *   BooleanUtils.toBooleanObject(Integer.valueOf(0))    = Boolean.FALSE
    571     *   BooleanUtils.toBooleanObject(Integer.valueOf(1))    = Boolean.TRUE
    572     *   BooleanUtils.toBooleanObject(Integer.valueOf(null)) = null
    573     * </pre>
    574     *
    575     * @param value  the Integer to convert
    576     * @return Boolean.TRUE if non-zero, Boolean.FALSE if zero,
    577     *  {@code null} if {@code null} input
    578     */
    579    public static Boolean toBooleanObject(final Integer value) {
    580        if (value == null) {
    581            return null;
    582        }
    583        return value.intValue() == 0 ? Boolean.FALSE : Boolean.TRUE;
    584    }
    585
    586    /**
    587     * <p>Converts an Integer to a Boolean specifying the conversion values.</p>
    588     *
    589     * <p>NOTE: This method may return {@code null} and may throw a {@code NullPointerException}
    590     * if unboxed to a {@code boolean}.</p>
    591     *
    592     * <p>The checks are done first for the {@code trueValue}, then for the {@code falseValue} and
    593     * finally for the {@code nullValue}.</p>
    594     **
    595     * <pre>
    596     *   BooleanUtils.toBooleanObject(Integer.valueOf(0), Integer.valueOf(0), Integer.valueOf(2), Integer.valueOf(3)) = Boolean.TRUE
    597     *   BooleanUtils.toBooleanObject(Integer.valueOf(0), Integer.valueOf(0), Integer.valueOf(0), Integer.valueOf(3)) = Boolean.TRUE
    598     *   BooleanUtils.toBooleanObject(Integer.valueOf(0), Integer.valueOf(0), Integer.valueOf(0), Integer.valueOf(0)) = Boolean.TRUE
    599     *   BooleanUtils.toBooleanObject(Integer.valueOf(2), Integer.valueOf(1), Integer.valueOf(2), Integer.valueOf(3)) = Boolean.FALSE
    600     *   BooleanUtils.toBooleanObject(Integer.valueOf(2), Integer.valueOf(1), Integer.valueOf(2), Integer.valueOf(2)) = Boolean.FALSE
    601     *   BooleanUtils.toBooleanObject(Integer.valueOf(3), Integer.valueOf(1), Integer.valueOf(2), Integer.valueOf(3)) = null
    602     * </pre>
    603     *
    604     * @param value  the Integer to convert
    605     * @param trueValue  the value to match for {@code true}, may be {@code null}
    606     * @param falseValue  the value to match for {@code false}, may be {@code null}
    607     * @param nullValue  the value to to match for {@code null}, may be {@code null}
    608     * @return Boolean.TRUE, Boolean.FALSE, or {@code null}
    609     * @throws IllegalArgumentException if no match
    610     */
    611    public static Boolean toBooleanObject(final Integer value, final Integer trueValue, final Integer falseValue, final Integer nullValue) {
    612        if (value == null) {
    613            if (trueValue == null) {
    614                return Boolean.TRUE;
    615            }
    616            if (falseValue == null) {
    617                return Boolean.FALSE;
    618            }
    619            if (nullValue == null) {
    620                return null;
    621            }
    622        } else if (value.equals(trueValue)) {
    623            return Boolean.TRUE;
    624        } else if (value.equals(falseValue)) {
    625            return Boolean.FALSE;
    626        } else if (value.equals(nullValue)) {
    627            return null;
    628        }
    629        throw new IllegalArgumentException("The Integer did not match any specified value");
    630    }
    631
    632    /**
    633     * <p>Converts a String to a Boolean.</p>
    634     *
    635     * <p>{@code 'true'}, {@code 'on'}, {@code 'y'}, {@code 't'}, {@code 'yes'}
    636     * or {@code '1'} (case insensitive) will return {@code true}.
    637     * {@code 'false'}, {@code 'off'}, {@code 'n'}, {@code 'f'}, {@code 'no'}
    638     * or {@code '0'} (case insensitive) will return {@code false}.
    639     * Otherwise, {@code null} is returned.</p>
    640     *
    641     * <p>NOTE: This method may return {@code null} and may throw a {@code NullPointerException}
    642     * if unboxed to a {@code boolean}.</p>
    643     *
    644     * <pre>
    645     *   // N.B. case is not significant
    646     *   BooleanUtils.toBooleanObject(null)    = null
    647     *   BooleanUtils.toBooleanObject("true")  = Boolean.TRUE
    648     *   BooleanUtils.toBooleanObject("T")     = Boolean.TRUE // i.e. T[RUE]
    649     *   BooleanUtils.toBooleanObject("false") = Boolean.FALSE
    650     *   BooleanUtils.toBooleanObject("f")     = Boolean.FALSE // i.e. f[alse]
    651     *   BooleanUtils.toBooleanObject("No")    = Boolean.FALSE
    652     *   BooleanUtils.toBooleanObject("n")     = Boolean.FALSE // i.e. n[o]
    653     *   BooleanUtils.toBooleanObject("on")    = Boolean.TRUE
    654     *   BooleanUtils.toBooleanObject("ON")    = Boolean.TRUE
    655     *   BooleanUtils.toBooleanObject("off")   = Boolean.FALSE
    656     *   BooleanUtils.toBooleanObject("oFf")   = Boolean.FALSE
    657     *   BooleanUtils.toBooleanObject("yes")   = Boolean.TRUE
    658     *   BooleanUtils.toBooleanObject("Y")     = Boolean.TRUE // i.e. Y[ES]
    659     *   BooleanUtils.toBooleanObject("1")     = Boolean.TRUE
    660     *   BooleanUtils.toBooleanObject("0")     = Boolean.FALSE
    661     *   BooleanUtils.toBooleanObject("blue")  = null
    662     *   BooleanUtils.toBooleanObject("true ") = null // trailing space (too long)
    663     *   BooleanUtils.toBooleanObject("ono")   = null // does not match on or no
    664     * </pre>
    665     *
    666     * @param str  the String to check; upper and lower case are treated as the same
    667     * @return the Boolean value of the string, {@code null} if no match or {@code null} input
    668     */
    669    public static Boolean toBooleanObject(final String str) {
    670        // Previously used equalsIgnoreCase, which was fast for interned 'true'.
    671        // Non interned 'true' matched 15 times slower.
    672        //
    673        // Optimisation provides same performance as before for interned 'true'.
    674        // Similar performance for null, 'false', and other strings not length 2/3/4.
    675        // 'true'/'TRUE' match 4 times slower, 'tRUE'/'True' 7 times slower.
    676        if (str == TRUE) {
    677            return Boolean.TRUE;
    678        }
    679        if (str == null) {
    680            return null;
    681        }
    682        switch (str.length()) {
    683            case 1: {
    684                final char ch0 = str.charAt(0);
    685                if (ch0 == 'y' || ch0 == 'Y' ||
    686                    ch0 == 't' || ch0 == 'T' ||
    687                    ch0 == '1') {
    688                    return Boolean.TRUE;
    689                }
    690                if (ch0 == 'n' || ch0 == 'N' ||
    691                    ch0 == 'f' || ch0 == 'F' ||
    692                    ch0 == '0') {
    693                    return Boolean.FALSE;
    694                }
    695                break;
    696            }
    697            case 2: {
    698                final char ch0 = str.charAt(0);
    699                final char ch1 = str.charAt(1);
    700                if ((ch0 == 'o' || ch0 == 'O') &&
    701                    (ch1 == 'n' || ch1 == 'N') ) {
    702                    return Boolean.TRUE;
    703                }
    704                if ((ch0 == 'n' || ch0 == 'N') &&
    705                    (ch1 == 'o' || ch1 == 'O') ) {
    706                    return Boolean.FALSE;
    707                }
    708                break;
    709            }
    710            case 3: {
    711                final char ch0 = str.charAt(0);
    712                final char ch1 = str.charAt(1);
    713                final char ch2 = str.charAt(2);
    714                if ((ch0 == 'y' || ch0 == 'Y') &&
    715                    (ch1 == 'e' || ch1 == 'E') &&
    716                    (ch2 == 's' || ch2 == 'S') ) {
    717                    return Boolean.TRUE;
    718                }
    719                if ((ch0 == 'o' || ch0 == 'O') &&
    720                    (ch1 == 'f' || ch1 == 'F') &&
    721                    (ch2 == 'f' || ch2 == 'F') ) {
    722                    return Boolean.FALSE;
    723                }
    724                break;
    725            }
    726            case 4: {
    727                final char ch0 = str.charAt(0);
    728                final char ch1 = str.charAt(1);
    729                final char ch2 = str.charAt(2);
    730                final char ch3 = str.charAt(3);
    731                if ((ch0 == 't' || ch0 == 'T') &&
    732                    (ch1 == 'r' || ch1 == 'R') &&
    733                    (ch2 == 'u' || ch2 == 'U') &&
    734                    (ch3 == 'e' || ch3 == 'E') ) {
    735                    return Boolean.TRUE;
    736                }
    737                break;
    738            }
    739            case 5: {
    740                final char ch0 = str.charAt(0);
    741                final char ch1 = str.charAt(1);
    742                final char ch2 = str.charAt(2);
    743                final char ch3 = str.charAt(3);
    744                final char ch4 = str.charAt(4);
    745                if ((ch0 == 'f' || ch0 == 'F') &&
    746                    (ch1 == 'a' || ch1 == 'A') &&
    747                    (ch2 == 'l' || ch2 == 'L') &&
    748                    (ch3 == 's' || ch3 == 'S') &&
    749                    (ch4 == 'e' || ch4 == 'E') ) {
    750                    return Boolean.FALSE;
    751                }
    752                break;
    753            }
    754        default:
    755            break;
    756        }
    757
    758        return null;
    759    }
    760
    761    /**
    762     * <p>Converts a String to a Boolean throwing an exception if no match.</p>
    763     *
    764     * <p>NOTE: This method may return {@code null} and may throw a {@code NullPointerException}
    765     * if unboxed to a {@code boolean}.</p>
    766     *
    767     * <pre>
    768     *   BooleanUtils.toBooleanObject("true", "true", "false", "null")   = Boolean.TRUE
    769     *   BooleanUtils.toBooleanObject(null, null, "false", "null")       = Boolean.TRUE
    770     *   BooleanUtils.toBooleanObject(null, null, null, "null")          = Boolean.TRUE
    771     *   BooleanUtils.toBooleanObject(null, null, null, null)            = Boolean.TRUE
    772     *   BooleanUtils.toBooleanObject("false", "true", "false", "null")  = Boolean.FALSE
    773     *   BooleanUtils.toBooleanObject("false", "true", "false", "false") = Boolean.FALSE
    774     *   BooleanUtils.toBooleanObject(null, "true", null, "false")       = Boolean.FALSE
    775     *   BooleanUtils.toBooleanObject(null, "true", null, null)          = Boolean.FALSE
    776     *   BooleanUtils.toBooleanObject("null", "true", "false", "null")   = null
    777     * </pre>
    778     *
    779     * @param str  the String to check
    780     * @param trueString  the String to match for {@code true} (case sensitive), may be {@code null}
    781     * @param falseString  the String to match for {@code false} (case sensitive), may be {@code null}
    782     * @param nullString  the String to match for {@code null} (case sensitive), may be {@code null}
    783     * @return the Boolean value of the string, {@code null} if either the String matches {@code nullString}
    784     *  or if {@code null} input and {@code nullString} is {@code null}
    785     * @throws IllegalArgumentException if the String doesn't match
    786     */
    787    public static Boolean toBooleanObject(final String str, final String trueString, final String falseString, final String nullString) {
    788        if (str == null) {
    789            if (trueString == null) {
    790                return Boolean.TRUE;
    791            }
    792            if (falseString == null) {
    793                return Boolean.FALSE;
    794            }
    795            if (nullString == null) {
    796                return null;
    797            }
    798        } else if (str.equals(trueString)) {
    799            return Boolean.TRUE;
    800        } else if (str.equals(falseString)) {
    801            return Boolean.FALSE;
    802        } else if (str.equals(nullString)) {
    803            return null;
    804        }
    805        // no match
    806        throw new IllegalArgumentException("The String did not match any specified value");
    807    }
    808
    809    /**
    810     * <p>Converts a boolean to an int using the convention that
    811     * {@code true} is {@code 1} and {@code false} is {@code 0}.</p>
    812     *
    813     * <pre>
    814     *   BooleanUtils.toInteger(true)  = 1
    815     *   BooleanUtils.toInteger(false) = 0
    816     * </pre>
    817     *
    818     * @param bool  the boolean to convert
    819     * @return one if {@code true}, zero if {@code false}
    820     */
    821    public static int toInteger(final boolean bool) {
    822        return bool ? 1 : 0;
    823    }
    824
    825    /**
    826     * <p>Converts a boolean to an int specifying the conversion values.</p>
    827     *
    828     * <pre>
    829     *   BooleanUtils.toInteger(true, 1, 0)  = 1
    830     *   BooleanUtils.toInteger(false, 1, 0) = 0
    831     * </pre>
    832     *
    833     * @param bool  the to convert
    834     * @param trueValue  the value to return if {@code true}
    835     * @param falseValue  the value to return if {@code false}
    836     * @return the appropriate value
    837     */
    838    public static int toInteger(final boolean bool, final int trueValue, final int falseValue) {
    839        return bool ? trueValue : falseValue;
    840    }
    841
    842    /**
    843     * <p>Converts a Boolean to an int specifying the conversion values.</p>
    844     *
    845     * <pre>
    846     *   BooleanUtils.toInteger(Boolean.TRUE, 1, 0, 2)  = 1
    847     *   BooleanUtils.toInteger(Boolean.FALSE, 1, 0, 2) = 0
    848     *   BooleanUtils.toInteger(null, 1, 0, 2)          = 2
    849     * </pre>
    850     *
    851     * @param bool  the Boolean to convert
    852     * @param trueValue  the value to return if {@code true}
    853     * @param falseValue  the value to return if {@code false}
    854     * @param nullValue  the value to return if {@code null}
    855     * @return the appropriate value
    856     */
    857    public static int toInteger(final Boolean bool, final int trueValue, final int falseValue, final int nullValue) {
    858        if (bool == null) {
    859            return nullValue;
    860        }
    861        return bool.booleanValue() ? trueValue : falseValue;
    862    }
    863
    864    /**
    865     * <p>Converts a boolean to an Integer using the convention that
    866     * {@code true} is {@code 1} and {@code false} is {@code 0}.</p>
    867     *
    868     * <pre>
    869     *   BooleanUtils.toIntegerObject(true)  = Integer.valueOf(1)
    870     *   BooleanUtils.toIntegerObject(false) = Integer.valueOf(0)
    871     * </pre>
    872     *
    873     * @param bool  the boolean to convert
    874     * @return one if {@code true}, zero if {@code false}
    875     */
    876    public static Integer toIntegerObject(final boolean bool) {
    877        return bool ? NumberUtils.INTEGER_ONE : NumberUtils.INTEGER_ZERO;
    878    }
    879
    880    /**
    881     * <p>Converts a boolean to an Integer specifying the conversion values.</p>
    882     *
    883     * <pre>
    884     *   BooleanUtils.toIntegerObject(true, Integer.valueOf(1), Integer.valueOf(0))  = Integer.valueOf(1)
    885     *   BooleanUtils.toIntegerObject(false, Integer.valueOf(1), Integer.valueOf(0)) = Integer.valueOf(0)
    886     * </pre>
    887     *
    888     * @param bool  the to convert
    889     * @param trueValue  the value to return if {@code true}, may be {@code null}
    890     * @param falseValue  the value to return if {@code false}, may be {@code null}
    891     * @return the appropriate value
    892     */
    893    public static Integer toIntegerObject(final boolean bool, final Integer trueValue, final Integer falseValue) {
    894        return bool ? trueValue : falseValue;
    895    }
    896
    897    /**
    898     * <p>Converts a Boolean to a Integer using the convention that
    899     * {@code zero} is {@code false}.</p>
    900     *
    901     * <p>{@code null} will be converted to {@code null}.</p>
    902     *
    903     * <pre>
    904     *   BooleanUtils.toIntegerObject(Boolean.TRUE)  = Integer.valueOf(1)
    905     *   BooleanUtils.toIntegerObject(Boolean.FALSE) = Integer.valueOf(0)
    906     * </pre>
    907     *
    908     * @param bool  the Boolean to convert
    909     * @return one if Boolean.TRUE, zero if Boolean.FALSE, {@code null} if {@code null}
    910     */
    911    public static Integer toIntegerObject(final Boolean bool) {
    912        if (bool == null) {
    913            return null;
    914        }
    915        return bool.booleanValue() ? NumberUtils.INTEGER_ONE : NumberUtils.INTEGER_ZERO;
    916    }
    917
    918    /**
    919     * <p>Converts a Boolean to an Integer specifying the conversion values.</p>
    920     *
    921     * <pre>
    922     *   BooleanUtils.toIntegerObject(Boolean.TRUE, Integer.valueOf(1), Integer.valueOf(0), Integer.valueOf(2))  = Integer.valueOf(1)
    923     *   BooleanUtils.toIntegerObject(Boolean.FALSE, Integer.valueOf(1), Integer.valueOf(0), Integer.valueOf(2)) = Integer.valueOf(0)
    924     *   BooleanUtils.toIntegerObject(null, Integer.valueOf(1), Integer.valueOf(0), Integer.valueOf(2))          = Integer.valueOf(2)
    925     * </pre>
    926     *
    927     * @param bool  the Boolean to convert
    928     * @param trueValue  the value to return if {@code true}, may be {@code null}
    929     * @param falseValue  the value to return if {@code false}, may be {@code null}
    930     * @param nullValue  the value to return if {@code null}, may be {@code null}
    931     * @return the appropriate value
    932     */
    933    public static Integer toIntegerObject(final Boolean bool, final Integer trueValue, final Integer falseValue, final Integer nullValue) {
    934        if (bool == null) {
    935            return nullValue;
    936        }
    937        return bool.booleanValue() ? trueValue : falseValue;
    938    }
    939
    940    /**
    941     * <p>Converts a boolean to a String returning one of the input Strings.</p>
    942     *
    943     * <pre>
    944     *   BooleanUtils.toString(true, "true", "false")   = "true"
    945     *   BooleanUtils.toString(false, "true", "false")  = "false"
    946     * </pre>
    947     *
    948     * @param bool  the Boolean to check
    949     * @param trueString  the String to return if {@code true}, may be {@code null}
    950     * @param falseString  the String to return if {@code false}, may be {@code null}
    951     * @return one of the two input Strings
    952     */
    953    public static String toString(final boolean bool, final String trueString, final String falseString) {
    954        return bool ? trueString : falseString;
    955    }
    956
    957    /**
    958     * <p>Converts a Boolean to a String returning one of the input Strings.</p>
    959     *
    960     * <pre>
    961     *   BooleanUtils.toString(Boolean.TRUE, "true", "false", null)   = "true"
    962     *   BooleanUtils.toString(Boolean.FALSE, "true", "false", null)  = "false"
    963     *   BooleanUtils.toString(null, "true", "false", null)           = null;
    964     * </pre>
    965     *
    966     * @param bool  the Boolean to check
    967     * @param trueString  the String to return if {@code true}, may be {@code null}
    968     * @param falseString  the String to return if {@code false}, may be {@code null}
    969     * @param nullString  the String to return if {@code null}, may be {@code null}
    970     * @return one of the three input Strings
    971     */
    972    public static String toString(final Boolean bool, final String trueString, final String falseString, final String nullString) {
    973        if (bool == null) {
    974            return nullString;
    975        }
    976        return bool.booleanValue() ? trueString : falseString;
    977    }
    978
    979    /**
    980     * <p>Converts a boolean to a String returning {@code 'on'}
    981     * or {@code 'off'}.</p>
    982     *
    983     * <pre>
    984     *   BooleanUtils.toStringOnOff(true)   = "on"
    985     *   BooleanUtils.toStringOnOff(false)  = "off"
    986     * </pre>
    987     *
    988     * @param bool  the Boolean to check
    989     * @return {@code 'on'}, {@code 'off'}, or {@code null}
    990     */
    991    public static String toStringOnOff(final boolean bool) {
    992        return toString(bool, ON, OFF);
    993    }
    994
    995    /**
    996     * <p>Converts a Boolean to a String returning {@code 'on'},
    997     * {@code 'off'}, or {@code null}.</p>
    998     *
    999     * <pre>
    1000     *   BooleanUtils.toStringOnOff(Boolean.TRUE)  = "on"
    1001     *   BooleanUtils.toStringOnOff(Boolean.FALSE) = "off"
    1002     *   BooleanUtils.toStringOnOff(null)          = null;
    1003     * </pre>
    1004     *
    1005     * @param bool  the Boolean to check
    1006     * @return {@code 'on'}, {@code 'off'}, or {@code null}
    1007     */
    1008    public static String toStringOnOff(final Boolean bool) {
    1009        return toString(bool, ON, OFF, null);
    1010    }
    1011
    1012    /**
    1013     * <p>Converts a boolean to a String returning {@code 'true'}
    1014     * or {@code 'false'}.</p>
    1015     *
    1016     * <pre>
    1017     *   BooleanUtils.toStringTrueFalse(true)   = "true"
    1018     *   BooleanUtils.toStringTrueFalse(false)  = "false"
    1019     * </pre>
    1020     *
    1021     * @param bool  the Boolean to check
    1022     * @return {@code 'true'}, {@code 'false'}, or {@code null}
    1023     */
    1024    public static String toStringTrueFalse(final boolean bool) {
    1025        return toString(bool, TRUE, FALSE);
    1026    }
    1027
    1028    /**
    1029     * <p>Converts a Boolean to a String returning {@code 'true'},
    1030     * {@code 'false'}, or {@code null}.</p>
    1031     *
    1032     * <pre>
    1033     *   BooleanUtils.toStringTrueFalse(Boolean.TRUE)  = "true"
    1034     *   BooleanUtils.toStringTrueFalse(Boolean.FALSE) = "false"
    1035     *   BooleanUtils.toStringTrueFalse(null)          = null;
    1036     * </pre>
    1037     *
    1038     * @param bool  the Boolean to check
    1039     * @return {@code 'true'}, {@code 'false'}, or {@code null}
    1040     */
    1041    public static String toStringTrueFalse(final Boolean bool) {
    1042        return toString(bool, TRUE, FALSE, null);
    1043    }
    1044
    1045    /**
    1046     * <p>Converts a boolean to a String returning {@code 'yes'}
    1047     * or {@code 'no'}.</p>
    1048     *
    1049     * <pre>
    1050     *   BooleanUtils.toStringYesNo(true)   = "yes"
    1051     *   BooleanUtils.toStringYesNo(false)  = "no"
    1052     * </pre>
    1053     *
    1054     * @param bool  the Boolean to check
    1055     * @return {@code 'yes'}, {@code 'no'}, or {@code null}
    1056     */
    1057    public static String toStringYesNo(final boolean bool) {
    1058        return toString(bool, YES, NO);
    1059    }
    1060
    1061    /**
    1062     * <p>Converts a Boolean to a String returning {@code 'yes'},
    1063     * {@code 'no'}, or {@code null}.</p>
    1064     *
    1065     * <pre>
    1066     *   BooleanUtils.toStringYesNo(Boolean.TRUE)  = "yes"
    1067     *   BooleanUtils.toStringYesNo(Boolean.FALSE) = "no"
    1068     *   BooleanUtils.toStringYesNo(null)          = null;
    1069     * </pre>
    1070     *
    1071     * @param bool  the Boolean to check
    1072     * @return {@code 'yes'}, {@code 'no'}, or {@code null}
    1073     */
    1074    public static String toStringYesNo(final Boolean bool) {
    1075        return toString(bool, YES, NO, null);
    1076    }
    1077
    1078    /**
    1079     * <p>Performs an xor on a set of booleans.</p>
    1080     *
    1081     * <pre>
    1082     *   BooleanUtils.xor(true, true)   = false
    1083     *   BooleanUtils.xor(false, false) = false
    1084     *   BooleanUtils.xor(true, false)  = true
    1085     * </pre>
    1086     *
    1087     * @param array  an array of {@code boolean}s
    1088     * @return the result of the xor operations
    1089     * @throws NullPointerException if {@code array} is {@code null}
    1090     * @throws IllegalArgumentException if {@code array} is empty.
    1091     */
    1092    public static boolean xor(final boolean... array) {
    1093        ObjectUtils.requireNonEmpty(array, "array");
    1094        // false if the neutral element of the xor operator
    1095        boolean result = false;
    1096        for (final boolean element : array) {
    1097            result ^= element;
    1098        }
    1099
    1100        return result;
    1101    }
    1102
    1103    /**
    1104     * <p>Performs an xor on an array of Booleans.</p>
    1105     *
    1106     * <pre>
    1107     *   BooleanUtils.xor(new Boolean[] { Boolean.TRUE, Boolean.TRUE })   = Boolean.FALSE
    1108     *   BooleanUtils.xor(new Boolean[] { Boolean.FALSE, Boolean.FALSE }) = Boolean.FALSE
    1109     *   BooleanUtils.xor(new Boolean[] { Boolean.TRUE, Boolean.FALSE })  = Boolean.TRUE
    1110     *   BooleanUtils.xor(Boolean.TRUE, Boolean.FALSE, Boolean.FALSE)     = Boolean.TRUE
    1111     * </pre>
    1112     *
    1113     * @param array  an array of {@code Boolean}s
    1114     * @return the result of the xor operations
    1115     * @throws NullPointerException if {@code array} is {@code null}
    1116     * @throws IllegalArgumentException if {@code array} is empty.
    1117     * @throws IllegalArgumentException if {@code array} contains a {@code null}
    1118     */
    1119    public static Boolean xor(final Boolean... array) {
    1120        ObjectUtils.requireNonEmpty(array, "array");
    1121        try {
    1122            final boolean[] primitive = ArrayUtils.toPrimitive(array);
    1123            return xor(primitive) ? Boolean.TRUE : Boolean.FALSE;
    1124        } catch (final NullPointerException ex) {
    1125            throw new IllegalArgumentException("The array must not contain any null elements");
    1126        }
    1127    }
    1128
    1129    /**
    1130     * <p>{@code BooleanUtils} instances should NOT be constructed in standard programming.
    1131     * Instead, the class should be used as {@code BooleanUtils.negate(true);}.</p>
    1132     *
    1133     * <p>This constructor is public to permit tools that require a JavaBean instance
    1134     * to operate.</p>
    1135     */
    1136    public BooleanUtils() {
    1137    }
    1138
    1139}