    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 *      https://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.math;
    018
    019import java.lang.reflect.Array;
    020import java.math.BigDecimal;
    021import java.math.BigInteger;
    022import java.math.RoundingMode;
    023import java.util.Objects;
    024
    025import org.apache.commons.lang3.CharUtils;
    026import org.apache.commons.lang3.StringUtils;
    027import org.apache.commons.lang3.Validate;
    028
    029/**
    030 * Provides extra functionality for Java Number classes.
    031 *
    032 * @since 2.0
    033 */
    034public class NumberUtils {
    035
    036    /** Reusable Long constant for zero. */
    037    public static final Long LONG_ZERO = Long.valueOf(0L);
    038    /** Reusable Long constant for one. */
    039    public static final Long LONG_ONE = Long.valueOf(1L);
    040    /** Reusable Long constant for minus one. */
    041    public static final Long LONG_MINUS_ONE = Long.valueOf(-1L);
    042    /** Reusable Integer constant for zero. */
    043    public static final Integer INTEGER_ZERO = Integer.valueOf(0);
    044    /** Reusable Integer constant for one. */
    045    public static final Integer INTEGER_ONE = Integer.valueOf(1);
    046    /** Reusable Integer constant for two */
    047    public static final Integer INTEGER_TWO = Integer.valueOf(2);
    048    /** Reusable Integer constant for minus one. */
    049    public static final Integer INTEGER_MINUS_ONE = Integer.valueOf(-1);
    050    /** Reusable Short constant for zero. */
    051    public static final Short SHORT_ZERO = Short.valueOf((short) 0);
    052    /** Reusable Short constant for one. */
    053    public static final Short SHORT_ONE = Short.valueOf((short) 1);
    054    /** Reusable Short constant for minus one. */
    055    public static final Short SHORT_MINUS_ONE = Short.valueOf((short) -1);
    056    /** Reusable Byte constant for zero. */
    057    public static final Byte BYTE_ZERO = Byte.valueOf((byte) 0);
    058    /** Reusable Byte constant for one. */
    059    public static final Byte BYTE_ONE = Byte.valueOf((byte) 1);
    060    /** Reusable Byte constant for minus one. */
    061    public static final Byte BYTE_MINUS_ONE = Byte.valueOf((byte) -1);
    062    /** Reusable Double constant for zero. */
    063    public static final Double DOUBLE_ZERO = Double.valueOf(0.0d);
    064    /** Reusable Double constant for one. */
    065    public static final Double DOUBLE_ONE = Double.valueOf(1.0d);
    066    /** Reusable Double constant for minus one. */
    067    public static final Double DOUBLE_MINUS_ONE = Double.valueOf(-1.0d);
    068    /** Reusable Float constant for zero. */
    069    public static final Float FLOAT_ZERO = Float.valueOf(0.0f);
    070    /** Reusable Float constant for one. */
    071    public static final Float FLOAT_ONE = Float.valueOf(1.0f);
    072    /** Reusable Float constant for minus one. */
    073    public static final Float FLOAT_MINUS_ONE = Float.valueOf(-1.0f);
    074
    075    /**
    076     * {@link Integer#MAX_VALUE} as a {@link Long}.
    077     *
    078     * @since 3.12.0
    079     */
    080    public static final Long LONG_INT_MAX_VALUE = Long.valueOf(Integer.MAX_VALUE);
    081
    082    /**
    083     * {@link Integer#MIN_VALUE} as a {@link Long}.
    084     *
    085     * @since 3.12.0
    086     */
    087    public static final Long LONG_INT_MIN_VALUE = Long.valueOf(Integer.MIN_VALUE);
    088
    089    /**
    090     * Compares two {@code byte} values numerically. This is the same functionality as provided in Java 7.
    091     *
    092     * @param x the first {@code byte} to compare.
    093     * @param y the second {@code byte} to compare.
    094     * @return the value {@code 0} if {@code x == y}; a value less than {@code 0} if {@code x < y}; and a value greater than {@code 0} if {@code x > y}.
    095     * @since 3.4
    096     * @deprecated Use {@link Byte#compare(byte, byte)}.
    097     */
    098    @Deprecated
    099    public static int compare(final byte x, final byte y) {
    100        return Byte.compare(x, y);
    101    }
    102
    103    /**
    104     * Compares two {@code int} values numerically. This is the same functionality as provided in Java 7.
    105     *
    106     * @param x the first {@code int} to compare.
    107     * @param y the second {@code int} to compare.
    108     * @return the value {@code 0} if {@code x == y}; a value less than {@code 0} if {@code x < y}; and a value greater than {@code 0} if {@code x > y}.
    109     * @since 3.4
    110     * @deprecated Use {@link Integer#compare(int, int)}.
    111     */
    112    @Deprecated
    113    public static int compare(final int x, final int y) {
    114        return Integer.compare(x, y);
    115    }
    116
    117    /**
    118     * Compares to {@code long} values numerically. This is the same functionality as provided in Java 7.
    119     *
    120     * @param x the first {@code long} to compare.
    121     * @param y the second {@code long} to compare.
    122     * @return the value {@code 0} if {@code x == y}; a value less than {@code 0} if {@code x < y}; and a value greater than {@code 0} if {@code x > y}.
    123     * @since 3.4
    124     * @deprecated Use {@link Long#compare(long, long)}.
    125     */
    126    @Deprecated
    127    public static int compare(final long x, final long y) {
    128        return Long.compare(x, y);
    129    }
    130
    131    /**
    132     * Compares to {@code short} values numerically. This is the same functionality as provided in Java 7.
    133     *
    134     * @param x the first {@code short} to compare.
    135     * @param y the second {@code short} to compare.
    136     * @return the value {@code 0} if {@code x == y}; a value less than {@code 0} if {@code x < y}; and a value greater than {@code 0} if {@code x > y}.
    137     * @since 3.4
    138     * @deprecated Use {@link Short#compare(short, short)}.
    139     */
    140    @Deprecated
    141    public static int compare(final short x, final short y) {
    142        return Short.compare(x, y);
    143    }
    144
    145    /**
    146     * Creates a {@link BigDecimal} from a {@link String}.
    147     *
    148     * <p>
    149     * Returns {@code null} if the string is {@code null}.
    150     * </p>
    151     *
    152     * @param str a {@link String} to convert, may be null.
    153     * @return converted {@link BigDecimal} (or null if the input is null).
    154     * @throws NumberFormatException if the value cannot be converted.
    155     */
    156    public static BigDecimal createBigDecimal(final String str) {
    157        if (str == null) {
    158            return null;
    159        }
    160        // handle JDK1.3.1 bug where "" throws IndexOutOfBoundsException
    161        if (StringUtils.isBlank(str)) {
    162            throw new NumberFormatException("A blank string is not a valid number");
    163        }
    164        return new BigDecimal(str);
    165    }
    166
    167    /**
    168     * Creates a {@link BigInteger} from a {@link String}.
    169     *
    170     * Handles hexadecimal (0x or #) and octal (0) notations.
    171     *
    172     * <p>
    173     * Returns {@code null} if the string is {@code null}.
    174     * </p>
    175     *
    176     * @param str a {@link String} to convert, may be null.
    177     * @return converted {@link BigInteger} (or null if the input is null).
    178     * @throws NumberFormatException if the value cannot be converted.
    179     * @since 3.2
    180     */
    181    public static BigInteger createBigInteger(final String str) {
    182        if (str == null) {
    183            return null;
    184        }
    185        if (str.isEmpty()) {
    186            throw new NumberFormatException("An empty string is not a valid number");
    187        }
    188        int pos = 0; // offset within string
    189        int radix = 10;
    190        boolean negate = false; // need to negate later?
    191        final char char0 = str.charAt(0);
    192        if (char0 == '-') {
    193            negate = true;
    194            pos = 1;
    195        } else if (char0 == '+') {
    196            pos = 1;
    197        }
    198        if (str.startsWith("0x", pos) || str.startsWith("0X", pos)) { // hex
    199            radix = 16;
    200            pos += 2;
    201        } else if (str.startsWith("#", pos)) { // alternative hex (allowed by Long/Integer)
    202            radix = 16;
    203            pos++;
    204        } else if (str.startsWith("0", pos) && str.length() > pos + 1) { // octal; so long as there are additional digits
    205            radix = 8;
    206            pos++;
    207        } // default is to treat as decimal
    208        final BigInteger value = new BigInteger(str.substring(pos), radix);
    209        return negate ? value.negate() : value;
    210    }
    211
    212    /**
    213     * Creates a {@link Double} from a {@link String}.
    214     *
    215     * <p>
    216     * Returns {@code null} if the string is {@code null}.
    217     * </p>
    218     *
    219     * @param str a {@link String} to convert, may be null.
    220     * @return converted {@link Double} (or null if the input is null).
    221     * @throws NumberFormatException if the value cannot be converted.
    222     */
    223    public static Double createDouble(final String str) {
    224        if (str == null) {
    225            return null;
    226        }
    227        return Double.valueOf(str);
    228    }
    229
    230    /**
    231     * Creates a {@link Float} from a {@link String}.
    232     *
    233     * <p>
    234     * Returns {@code null} if the string is {@code null}.
    235     * </p>
    236     *
    237     * @param str a {@link String} to convert, may be null.
    238     * @return converted {@link Float} (or null if the input is null).
    239     * @throws NumberFormatException if the value cannot be converted.
    240     */
    241    public static Float createFloat(final String str) {
    242        if (str == null) {
    243            return null;
    244        }
    245        return Float.valueOf(str);
    246    }
    247
    248    /**
    249     * Creates an {@link Integer} from a {@link String}.
    250     *
    251     * Handles hexadecimal (0xhhhh) and octal (0dddd) notations. A leading zero means octal; spaces are not trimmed.
    252     *
    253     * <p>
    254     * Returns {@code null} if the string is {@code null}.
    255     * </p>
    256     *
    257     * @param str a {@link String} to convert, may be null.
    258     * @return converted {@link Integer} (or null if the input is null).
    259     * @throws NumberFormatException if the value cannot be converted.
    260     */
    261    public static Integer createInteger(final String str) {
    262        if (str == null) {
    263            return null;
    264        }
    265        // decode() handles 0xAABD and 0777 (hex and octal) as well.
    266        return Integer.decode(str);
    267    }
    268
    269    /**
    270     * Creates a {@link Long} from a {@link String}.
    271     *
    272     * Handles hexadecimal (0Xhhhh) and octal (0ddd) notations. A leading zero means octal; spaces are not trimmed.
    273     *
    274     * <p>
    275     * Returns {@code null} if the string is {@code null}.
    276     * </p>
    277     *
    278     * @param str a {@link String} to convert, may be null.
    279     * @return converted {@link Long} (or null if the input is null).
    280     * @throws NumberFormatException if the value cannot be converted.
    281     * @since 3.1
    282     */
    283    public static Long createLong(final String str) {
    284        if (str == null) {
    285            return null;
    286        }
    287        return Long.decode(str);
    288    }
    289
    290    /**
    291     * Creates a {@link Number} from a {@link String}.
    292     *
    293     * <p>
    294     * If the string starts with {@code 0x} or {@code -0x} (lower or upper case) or {@code #} or {@code -#}, it will be interpreted as a hexadecimal Integer -
    295     * or Long, if the number of digits after the prefix is more than 8 - or BigInteger if there are more than 16 digits.
    296     * </p>
    297     * <p>
    298     * Then, the value is examined for a type qualifier on the end, i.e. one of {@code 'f', 'F', 'd', 'D', 'l', 'L'}. If it is found, it starts trying to create
    299     * successively larger types from the type specified until one is found that can represent the value.
    300     * </p>
    301     *
    302     * <p>
    303     * If a type specifier is not found, it will check for a decimal point and then try successively larger types from {@link Integer} to {@link BigInteger} and
    304     * from {@link Float} to {@link BigDecimal}.
    305     * </p>
    306     *
    307     * <p>
    308     * Integral values with a leading {@code 0} will be interpreted as octal; the returned number will be Integer, Long or BigDecimal as appropriate.
    309     * </p>
    310     *
    311     * <p>
    312     * Returns {@code null} if the string is {@code null}.
    313     * </p>
    314     *
    315     * <p>
    316     * This method does not trim the input string, i.e., strings with leading or trailing spaces will generate NumberFormatExceptions.
    317     * </p>
    318     *
    319     * @param str String containing a number, may be null.
    320     * @return Number created from the string (or null if the input is null).
    321     * @throws NumberFormatException if the value cannot be converted.
    322     */
    323    public static Number createNumber(final String str) {
    324        if (str == null) {
    325            return null;
    326        }
    327        if (StringUtils.isBlank(str)) {
    328            throw new NumberFormatException("A blank string is not a valid number");
    329        }
    330        // Need to deal with all possible hex prefixes here
    331        final String[] hexPrefixes = { "0x", "0X", "#" };
    332        final int length = str.length();
    333        final int offset = isSign(str.charAt(0)) ? 1 : 0;
    334        int pfxLen = 0;
    335        for (final String pfx : hexPrefixes) {
    336            if (str.startsWith(pfx, offset)) {
    337                pfxLen += pfx.length() + offset;
    338                break;
    339            }
    340        }
    341        if (pfxLen > 0) { // we have a hex number
    342            char firstSigDigit = 0; // strip leading zeroes
    343            for (int i = pfxLen; i < length; i++) {
    344                firstSigDigit = str.charAt(i);
    345                if (firstSigDigit != '0') {
    346                    break;
    347                }
    348                pfxLen++;
    349            }
    350            final int hexDigits = length - pfxLen;
    351            if (hexDigits > 16 || hexDigits == 16 && firstSigDigit > '7') { // too many for Long
    352                return createBigInteger(str);
    353            }
    354            if (hexDigits > 8 || hexDigits == 8 && firstSigDigit > '7') { // too many for an int
    355                return createLong(str);
    356            }
    357            return createInteger(str);
    358        }
    359        final char lastChar = str.charAt(length - 1);
    360        final String mant;
    361        final String dec;
    362        final String exp;
    363        final int decPos = str.indexOf('.');
    364        final int expPos = str.indexOf('e') + str.indexOf('E') + 1; // assumes both not present
    365        // if both e and E are present, this is caught by the checks on expPos (which prevent IOOBE)
    366        // and the parsing which will detect if e or E appear in a number due to using the wrong offset
    367        // Detect if the return type has been requested
    368        final boolean requestType = !Character.isDigit(lastChar) && lastChar != '.';
    369        if (decPos > -1) { // there is a decimal point
    370            if (expPos > -1) { // there is an exponent
    371                if (expPos <= decPos || expPos > length) { // prevents double exponent causing IOOBE
    372                    throw new NumberFormatException(str + " is not a valid number.");
    373                }
    374                dec = str.substring(decPos + 1, expPos);
    375            } else {
    376                // No exponent, but there may be a type character to remove
    377                dec = str.substring(decPos + 1, requestType ? length - 1 : length);
    378            }
    379            mant = getMantissa(str, decPos);
    380        } else {
    381            if (expPos > -1) {
    382                if (expPos > length) { // prevents double exponent causing IOOBE
    383                    throw new NumberFormatException(str + " is not a valid number.");
    384                }
    385                mant = getMantissa(str, expPos);
    386            } else {
    387                // No decimal, no exponent, but there may be a type character to remove
    388                mant = getMantissa(str, requestType ? length - 1 : length);
    389            }
    390            dec = null;
    391        }
    392        if (requestType) {
    393            if (expPos > -1 && expPos < length - 1) {
    394                exp = str.substring(expPos + 1, length - 1);
    395            } else {
    396                exp = null;
    397            }
    398            // Requesting a specific type.
    399            final String numeric = str.substring(0, length - 1);
    400            switch (lastChar) {
    401            case 'l':
    402            case 'L':
    403                if (dec == null && exp == null && (!numeric.isEmpty() && numeric.charAt(0) == '-' && isDigits(numeric.substring(1)) || isDigits(numeric))) {
    404                    try {
    405                        return createLong(numeric);
    406                    } catch (final NumberFormatException ignored) {
    407                        // Too big for a long
    408                    }
    409                    return createBigInteger(numeric);
    410                }
    411                throw new NumberFormatException(str + " is not a valid number.");
    412            case 'f':
    413            case 'F':
    414                try {
    415                    final Float f = createFloat(str);
    416                    if (!(f.isInfinite() || f.floatValue() == 0.0F && !isZero(mant, dec))) {
    417                        // If it's too big for a float or the float value = 0 and the string
    418                        // has non-zeros in it, then float does not have the precision we want
    419                        return f;
    420                    }
    421                } catch (final NumberFormatException ignored) {
    422                    // ignore the bad number
    423                }
    424                // falls-through
    425            case 'd':
    426            case 'D':
    427                try {
    428                    final Double d = createDouble(str);
    429                    if (!(d.isInfinite() || d.doubleValue() == 0.0D && !isZero(mant, dec))) {
    430                        return d;
    431                    }
    432                } catch (final NumberFormatException ignored) {
    433                    // ignore the bad number
    434                }
    435                try {
    436                    return createBigDecimal(numeric);
    437                } catch (final NumberFormatException ignored) {
    438                    // ignore the bad number
    439                }
    440                // falls-through
    441            default:
    442                throw new NumberFormatException(str + " is not a valid number.");
    443            }
    444        }
    445        // User doesn't have a preference on the return type, so let's start
    446        // small and go from there...
    447        if (expPos > -1 && expPos < length - 1) {
    448            exp = str.substring(expPos + 1);
    449        } else {
    450            exp = null;
    451        }
    452        if (dec == null && exp == null) { // no decimal point and no exponent
    453            // Must be an Integer, Long, Biginteger
    454            try {
    455                return createInteger(str);
    456            } catch (final NumberFormatException ignored) {
    457                // ignore the bad number
    458            }
    459            try {
    460                return createLong(str);
    461            } catch (final NumberFormatException ignored) {
    462                // ignore the bad number
    463            }
    464            return createBigInteger(str);
    465        }
    466        // Must be a Float, Double, BigDecimal
    467        try {
    468            final Float f = createFloat(str);
    469            final Double d = createDouble(str);
    470            if (!f.isInfinite() && !(f.floatValue() == 0.0F && !isZero(mant, dec)) && f.toString().equals(d.toString())) {
    471                return f;
    472            }
    473            if (!d.isInfinite() && !(d.doubleValue() == 0.0D && !isZero(mant, dec))) {
    474                final BigDecimal b = createBigDecimal(str);
    475                if (b.compareTo(BigDecimal.valueOf(d.doubleValue())) == 0) {
    476                    return d;
    477                }
    478                return b;
    479            }
    480        } catch (final NumberFormatException ignored) {
    481            // ignore the bad number
    482        }
    483        return createBigDecimal(str);
    484    }
    485
    486    /**
    487     * Utility method for {@link #createNumber(String)}.
    488     *
    489     * <p>
    490     * Returns mantissa of the given number.
    491     * </p>
    492     *
    493     * @param str     the string representation of the number.
    494     * @param stopPos the position of the exponent or decimal point.
    495     * @return mantissa of the given number.
    496     * @throws NumberFormatException if no mantissa can be retrieved.
    497     */
    498    private static String getMantissa(final String str, final int stopPos) {
    499        final char firstChar = str.charAt(0);
    500        final boolean hasSign = isSign(firstChar);
    501        final int length = str.length();
    502        if (length <= (hasSign ? 1 : 0) || length < stopPos) {
    503            throw new NumberFormatException(str + " is not a valid number.");
    504        }
    505        return hasSign ? str.substring(1, stopPos) : str.substring(0, stopPos);
    506    }
    507
    508    /**
    509     * Utility method for {@link #createNumber(java.lang.String)}.
    510     *
    511     * <p>
    512     * Returns {@code true} if s is {@code null} or empty.
    513     * </p>
    514     *
    515     * @param str the String to check.
    516     * @return if it is all zeros or {@code null}.
    517     */
    518    private static boolean isAllZeros(final String str) {
    519        if (str == null) {
    520            return true;
    521        }
    522        for (int i = str.length() - 1; i >= 0; i--) {
    523            if (str.charAt(i) != '0') {
    524                return false;
    525            }
    526        }
    527        return true;
    528    }
    529
    530    /**
    531     * Checks whether the String is a valid Java number.
    532     *
    533     * <p>
    534     * Valid numbers include hexadecimal marked with the {@code 0x} or {@code 0X} qualifier, octal numbers, scientific notation and numbers marked with a type
    535     * qualifier (e.g. 123L).
    536     * </p>
    537     *
    538     * <p>
    539     * Non-hexadecimal strings beginning with a leading zero are treated as octal values. Thus the string {@code 09} will return {@code false}, since {@code 9}
    540     * is not a valid octal value. However, numbers beginning with {@code 0.} are treated as decimal.
    541     * </p>
    542     *
    543     * <p>
    544     * {@code null} and empty/blank {@link String} will return {@code false}.
    545     * </p>
    546     *
    547     * <p>
    548     * Note, {@link #createNumber(String)} should return a number for every input resulting in {@code true}.
    549     * </p>
    550     *
    551     * @param str the {@link String} to check.
    552     * @return {@code true} if the string is a correctly formatted number.
    553     * @since 3.5
    554     */
    555    public static boolean isCreatable(final String str) {
    556        if (StringUtils.isEmpty(str)) {
    557            return false;
    558        }
    559        final char[] chars = str.toCharArray();
    560        int sz = chars.length;
    561        boolean hasExp = false;
    562        boolean hasDecPoint = false;
    563        boolean allowSigns = false;
    564        boolean foundDigit = false;
    565        // deal with any possible sign up front
    566        final int start = isSign(chars[0]) ? 1 : 0;
    567        if (sz > start + 1 && chars[start] == '0' && !StringUtils.contains(str, '.')) { // leading 0, skip if is a decimal number
    568            if (chars[start + 1] == 'x' || chars[start + 1] == 'X') { // leading 0x/0X
    569                int i = start + 2;
    570                if (i == sz) {
    571                    return false; // str == "0x"
    572                }
    573                // checking hex (it can't be anything else)
    574                for (; i < chars.length; i++) {
    575                    if (!CharUtils.isHex(chars[i])) {
    576                        return false;
    577                    }
    578                }
    579                return true;
    580            }
    581            if (Character.isDigit(chars[start + 1])) {
    582                // leading 0, but not hex, must be octal
    583                int i = start + 1;
    584                for (; i < chars.length; i++) {
    585                    if (!CharUtils.isOctal(chars[i])) {
    586                        return false;
    587                    }
    588                }
    589                return true;
    590            }
    591        }
    592        sz--; // don't want to loop to the last char, check it afterwards
    593              // for type qualifiers
    594        int i = start;
    595        // loop to the next to last char or to the last char if we need another digit to
    596        // make a valid number (e.g. chars[0..5] = "1234E")
    597        while (i < sz || i < sz + 1 && allowSigns && !foundDigit) {
    598            if (CharUtils.isAsciiNumeric(chars[i])) {
    599                foundDigit = true;
    600                allowSigns = false;
    601            } else if (chars[i] == '.') {
    602                if (hasDecPoint || hasExp) {
    603                    // two decimal points or dec in exponent
    604                    return false;
    605                }
    606                hasDecPoint = true;
    607            } else if (chars[i] == 'e' || chars[i] == 'E') {
    608                // we've already taken care of hex.
    609                if (hasExp) {
    610                    // two E's
    611                    return false;
    612                }
    613                if (!foundDigit) {
    614                    return false;
    615                }
    616                hasExp = true;
    617                allowSigns = true;
    618            } else if (isSign(chars[i])) {
    619                if (!allowSigns) {
    620                    return false;
    621                }
    622                allowSigns = false;
    623                foundDigit = false; // we need a digit after the E
    624            } else {
    625                return false;
    626            }
    627            i++;
    628        }
    629        if (i < chars.length) {
    630            if (CharUtils.isAsciiNumeric(chars[i])) {
    631                // no type qualifier, OK
    632                return true;
    633            }
    634            if (chars[i] == 'e' || chars[i] == 'E') {
    635                // can't have an E at the last byte
    636                return false;
    637            }
    638            if (chars[i] == '.') {
    639                if (hasDecPoint || hasExp) {
    640                    // two decimal points or dec in exponent
    641                    return false;
    642                }
    643                // single trailing decimal point after non-exponent is ok
    644                return foundDigit;
    645            }
    646            if (!allowSigns && (chars[i] == 'd' || chars[i] == 'D' || chars[i] == 'f' || chars[i] == 'F')) {
    647                return foundDigit;
    648            }
    649            if (chars[i] == 'l' || chars[i] == 'L') {
    650                // not allowing L with an exponent or decimal point
    651                return foundDigit && !hasExp && !hasDecPoint;
    652            }
    653            // last character is illegal
    654            return false;
    655        }
    656        // allowSigns is true iff the val ends in 'E'
    657        // found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
    658        return !allowSigns && foundDigit;
    659    }
    660
    661    /**
    662     * Checks whether the {@link String} contains only digit characters.
    663     *
    664     * <p>
    665     * {@code null} and empty String will return {@code false}.
    666     * </p>
    667     *
    668     * @param str the {@link String} to check
    669     * @return {@code true} if str contains only Unicode numeric
    670     */
    671    public static boolean isDigits(final String str) {
    672        return StringUtils.isNumeric(str);
    673    }
    674
    675    /**
    676     * Checks whether the String is a valid Java number.
    677     *
    678     * <p>
    679     * Valid numbers include hexadecimal marked with the {@code 0x} or {@code 0X} qualifier, octal numbers, scientific notation and numbers marked with a type
    680     * qualifier (e.g. 123L).
    681     * </p>
    682     *
    683     * <p>
    684     * Non-hexadecimal strings beginning with a leading zero are treated as octal values. Thus the string {@code 09} will return {@code false}, since {@code 9}
    685     * is not a valid octal value. However, numbers beginning with {@code 0.} are treated as decimal.
    686     * </p>
    687     *
    688     * <p>
    689     * {@code null} and empty/blank {@link String} will return {@code false}.
    690     * </p>
    691     *
    692     * <p>
    693     * Note, {@link #createNumber(String)} should return a number for every input resulting in {@code true}.
    694     * </p>
    695     *
    696     * @param str the {@link String} to check.
    697     * @return {@code true} if the string is a correctly formatted number.
    698     * @since 3.3 the code supports hexadecimal {@code 0Xhhh} an octal {@code 0ddd} validation.
    699     * @deprecated This feature will be removed in Lang 4, use {@link NumberUtils#isCreatable(String)} instead.
    700     */
    701    @Deprecated
    702    public static boolean isNumber(final String str) {
    703        return isCreatable(str);
    704    }
    705
    706    /**
    707     * Checks whether the given String is a parsable number.
    708     *
    709     * <p>
    710     * Parsable numbers include those Strings understood by {@link Integer#parseInt(String)}, {@link Long#parseLong(String)}, {@link Float#parseFloat(String)}
    711     * or {@link Double#parseDouble(String)}. This method can be used instead of catching {@link java.text.ParseException} when calling one of those methods.
    712     * </p>
    713     *
    714     * <p>
    715     * Hexadecimal and scientific notations are <strong>not</strong> considered parsable. See {@link #isCreatable(String)} on those cases.
    716     * </p>
    717     *
    718     * <p>
    719     * {@code null} and empty String will return {@code false}.
    720     * </p>
    721     *
    722     * @param str the String to check.
    723     * @return {@code true} if the string is a parsable number.
    724     * @since 3.4
    725     */
    726    public static boolean isParsable(final String str) {
    727        if (StringUtils.isEmpty(str)) {
    728            return false;
    729        }
    730        if (str.charAt(str.length() - 1) == '.') {
    731            return false;
    732        }
    733        if (str.charAt(0) == '-') {
    734            if (str.length() == 1) {
    735                return false;
    736            }
    737            return withDecimalsParsing(str, 1);
    738        }
    739        return withDecimalsParsing(str, 0);
    740    }
    741
    742    private static boolean isSign(final char ch) {
    743        return ch == '-' || ch == '+';
    744    }
    745
    746    /**
    747     * Utility method for {@link #createNumber(java.lang.String)}.
    748     *
    749     * <p>
    750     * This will check if the magnitude of the number is zero by checking if there are only zeros before and after the decimal place.
    751     * </p>
    752     *
    753     * <p>
    754     * Note: It is <strong>assumed</strong> that the input string has been converted to either a Float or Double with a value of zero when this method is
    755     * called. This eliminates invalid input for example {@code ".", ".D", ".e0"}.
    756     * </p>
    757     *
    758     * <p>
    759     * Thus the method only requires checking if both arguments are null, empty or contain only zeros.
    760     * </p>
    761     *
    762     * <p>
    763     * Given {@code s = mant + "." + dec}:
    764     * </p>
    765     * <ul>
    766     * <li>{@code true} if s is {@code "0.0"}
    767     * <li>{@code true} if s is {@code "0."}
    768     * <li>{@code true} if s is {@code ".0"}
    769     * <li>{@code false} otherwise (this assumes {@code "."} is not possible)
    770     * </ul>
    771     *
    772     * @param mant the mantissa decimal digits before the decimal point (sign must be removed; never null).
    773     * @param dec  the decimal digits after the decimal point (exponent and type specifier removed; can be null)
    774     * @return true if the magnitude is zero.
    775     */
    776    private static boolean isZero(final String mant, final String dec) {
    777        return isAllZeros(mant) && isAllZeros(dec);
    778    }
    779
    780    /**
    781     * Returns the maximum value in an array.
    782     *
    783     * @param array an array, must not be null or empty.
    784     * @return the maximum value in the array.
    785     * @throws NullPointerException     if {@code array} is {@code null}.
    786     * @throws IllegalArgumentException if {@code array} is empty.
    787     * @since 3.4 Changed signature from max(byte[]) to max(byte...).
    788     */
    789    public static byte max(final byte... array) {
    790        // Validates input
    791        validateArray(array);
    792        // Finds and returns max
    793        byte max = array[0];
    794        for (int i = 1; i < array.length; i++) {
    795            if (array[i] > max) {
    796                max = array[i];
    797            }
    798        }
    799        return max;
    800    }
    801
    802    /**
    803     * Gets the maximum of three {@code byte} values.
    804     *
    805     * @param a value 1.
    806     * @param b value 2.
    807     * @param c value 3.
    808     * @return the largest of the values.
    809     */
    810    public static byte max(byte a, final byte b, final byte c) {
    811        if (b > a) {
    812            a = b;
    813        }
    814        if (c > a) {
    815            a = c;
    816        }
    817        return a;
    818    }
    819
    820    /**
    821     * Returns the maximum value in an array.
    822     *
    823     * @param array an array, must not be null or empty.
    824     * @return the maximum value in the array.
    825     * @throws NullPointerException     if {@code array} is {@code null}.
    826     * @throws IllegalArgumentException if {@code array} is empty.
    827     * @see IEEE754rUtils#max(double[]) IEEE754rUtils for a version of this method that handles NaN differently.
    828     * @since 3.4 Changed signature from max(double[]) to max(double...)
    829     */
    830    public static double max(final double... array) {
    831        // Validates input
    832        validateArray(array);
    833        // Finds and returns max
    834        double max = array[0];
    835        for (int j = 1; j < array.length; j++) {
    836            if (Double.isNaN(array[j])) {
    837                return Double.NaN;
    838            }
    839            if (array[j] > max) {
    840                max = array[j];
    841            }
    842        }
    843        return max;
    844    }
    845
    846    /**
    847     * Gets the maximum of three {@code double} values.
    848     *
    849     * <p>
    850     * If any value is {@code NaN}, {@code NaN} is returned. Infinity is handled.
    851     * </p>
    852     *
    853     * @param a value 1.
    854     * @param b value 2.
    855     * @param c value 3.
    856     * @return the largest of the values.
    857     * @see IEEE754rUtils#max(double, double, double) for a version of this method that handles NaN differently.
    858     */
    859    public static double max(final double a, final double b, final double c) {
    860        return Math.max(Math.max(a, b), c);
    861    }
    862
    863    /**
    864     * Returns the maximum value in an array.
    865     *
    866     * @param array an array, must not be null or empty.
    867     * @return the maximum value in the array.
    868     * @throws NullPointerException     if {@code array} is {@code null}.
    869     * @throws IllegalArgumentException if {@code array} is empty.
    870     * @see IEEE754rUtils#max(float[]) IEEE754rUtils for a version of this method that handles NaN differently.
    871     * @since 3.4 Changed signature from max(float[]) to max(float...).
    872     */
    873    public static float max(final float... array) {
    874        // Validates input
    875        validateArray(array);
    876        // Finds and returns max
    877        float max = array[0];
    878        for (int j = 1; j < array.length; j++) {
    879            if (Float.isNaN(array[j])) {
    880                return Float.NaN;
    881            }
    882            if (array[j] > max) {
    883                max = array[j];
    884            }
    885        }
    886        return max;
    887    }
    888    // must handle Long, Float, Integer, Float, Short,
    889    // BigDecimal, BigInteger and Byte
    890    // useful methods:
    891    // Byte.decode(String)
    892    // Byte.valueOf(String, int radix)
    893    // Byte.valueOf(String)
    894    // Double.valueOf(String)
    895    // Float.valueOf(String)
    896    // Float.valueOf(String)
    897    // Integer.valueOf(String, int radix)
    898    // Integer.valueOf(String)
    899    // Integer.decode(String)
    900    // Integer.getInteger(String)
    901    // Integer.getInteger(String, int val)
    902    // Integer.getInteger(String, Integer val)
    903    // Integer.valueOf(String)
    904    // Double.valueOf(String)
    905    // new Byte(String)
    906    // Long.valueOf(String)
    907    // Long.getLong(String)
    908    // Long.getLong(String, int)
    909    // Long.getLong(String, Integer)
    910    // Long.valueOf(String, int)
    911    // Long.valueOf(String)
    912    // Short.valueOf(String)
    913    // Short.decode(String)
    914    // Short.valueOf(String, int)
    915    // Short.valueOf(String)
    916    // new BigDecimal(String)
    917    // new BigInteger(String)
    918    // new BigInteger(String, int radix)
    919    // Possible inputs:
    920    // 45 45.5 45E7 4.5E7 Hex Oct Binary xxxF xxxD xxxf xxxd
    921    // plus minus everything. Prolly more. A lot are not separable.
    922
    923    /**
    924     * Gets the maximum of three {@code float} values.
    925     *
    926     * <p>
    927     * If any value is {@code NaN}, {@code NaN} is returned. Infinity is handled.
    928     * </p>
    929     *
    930     * @param a value 1.
    931     * @param b value 2.
    932     * @param c value 3.
    933     * @return the largest of the values.
    934     * @see IEEE754rUtils#max(float, float, float) for a version of this method that handles NaN differently.
    935     */
    936    public static float max(final float a, final float b, final float c) {
    937        return Math.max(Math.max(a, b), c);
    938    }
    939
    940    /**
    941     * Returns the maximum value in an array.
    942     *
    943     * @param array an array, must not be null or empty.
    944     * @return the maximum value in the array.
    945     * @throws NullPointerException     if {@code array} is {@code null}.
    946     * @throws IllegalArgumentException if {@code array} is empty.
    947     * @since 3.4 Changed signature from max(int[]) to max(int...).
    948     */
    949    public static int max(final int... array) {
    950        // Validates input
    951        validateArray(array);
    952        // Finds and returns max
    953        int max = array[0];
    954        for (int j = 1; j < array.length; j++) {
    955            if (array[j] > max) {
    956                max = array[j];
    957            }
    958        }
    959        return max;
    960    }
    961
    962    /**
    963     * Gets the maximum of three {@code int} values.
    964     *
    965     * @param a value 1.
    966     * @param b value 2.
    967     * @param c value 3.
    968     * @return the largest of the values.
    969     */
    970    public static int max(int a, final int b, final int c) {
    971        if (b > a) {
    972            a = b;
    973        }
    974        if (c > a) {
    975            a = c;
    976        }
    977        return a;
    978    }
    979
    980    /**
    981     * Returns the maximum value in an array.
    982     *
    983     * @param array an array, must not be null or empty.
    984     * @return the maximum value in the array.
    985     * @throws NullPointerException     if {@code array} is {@code null}.
    986     * @throws IllegalArgumentException if {@code array} is empty.
    987     * @since 3.4 Changed signature from max(long[]) to max(long...).
    988     */
    989    public static long max(final long... array) {
    990        // Validates input
    991        validateArray(array);
    992        // Finds and returns max
    993        long max = array[0];
    994        for (int j = 1; j < array.length; j++) {
    995            if (array[j] > max) {
    996                max = array[j];
    997            }
    998        }
    999        return max;
    1000    }
    1001
    1002    // 3 param max
    1003    /**
    1004     * Gets the maximum of three {@code long} values.
    1005     *
    1006     * @param a value 1.
    1007     * @param b value 2.
    1008     * @param c value 3.
    1009     * @return the largest of the values.
    1010     */
    1011    public static long max(long a, final long b, final long c) {
    1012        if (b > a) {
    1013            a = b;
    1014        }
    1015        if (c > a) {
    1016            a = c;
    1017        }
    1018        return a;
    1019    }
    1020
    1021    /**
    1022     * Returns the maximum value in an array.
    1023     *
    1024     * @param array an array, must not be null or empty.
    1025     * @return the maximum value in the array.
    1026     * @throws NullPointerException     if {@code array} is {@code null}.
    1027     * @throws IllegalArgumentException if {@code array} is empty.
    1028     * @since 3.4 Changed signature from max(short[]) to max(short...).
    1029     */
    1030    public static short max(final short... array) {
    1031        // Validates input
    1032        validateArray(array);
    1033        // Finds and returns max
    1034        short max = array[0];
    1035        for (int i = 1; i < array.length; i++) {
    1036            if (array[i] > max) {
    1037                max = array[i];
    1038            }
    1039        }
    1040        return max;
    1041    }
    1042
    1043    /**
    1044     * Gets the maximum of three {@code short} values.
    1045     *
    1046     * @param a value 1.
    1047     * @param b value 2.
    1048     * @param c value 3.
    1049     * @return the largest of the values.
    1050     */
    1051    public static short max(short a, final short b, final short c) {
    1052        if (b > a) {
    1053            a = b;
    1054        }
    1055        if (c > a) {
    1056            a = c;
    1057        }
    1058        return a;
    1059    }
    1060
    1061    /**
    1062     * Returns the minimum value in an array.
    1063     *
    1064     * @param array an array, must not be null or empty.
    1065     * @return the minimum value in the array.
    1066     * @throws NullPointerException     if {@code array} is {@code null}.
    1067     * @throws IllegalArgumentException if {@code array} is empty.
    1068     * @since 3.4 Changed signature from min(byte[]) to min(byte...).
    1069     */
    1070    public static byte min(final byte... array) {
    1071        // Validates input
    1072        validateArray(array);
    1073        // Finds and returns min
    1074        byte min = array[0];
    1075        for (int i = 1; i < array.length; i++) {
    1076            if (array[i] < min) {
    1077                min = array[i];
    1078            }
    1079        }
    1080        return min;
    1081    }
    1082
    1083    /**
    1084     * Gets the minimum of three {@code byte} values.
    1085     *
    1086     * @param a value 1.
    1087     * @param b value 2.
    1088     * @param c value 3.
    1089     * @return the smallest of the values.
    1090     */
    1091    public static byte min(byte a, final byte b, final byte c) {
    1092        if (b < a) {
    1093            a = b;
    1094        }
    1095        if (c < a) {
    1096            a = c;
    1097        }
    1098        return a;
    1099    }
    1100
    1101    /**
    1102     * Returns the minimum value in an array.
    1103     *
    1104     * @param array an array, must not be null or empty.
    1105     * @return the minimum value in the array.
    1106     * @throws NullPointerException     if {@code array} is {@code null}.
    1107     * @throws IllegalArgumentException if {@code array} is empty.
    1108     * @see IEEE754rUtils#min(double[]) IEEE754rUtils for a version of this method that handles NaN differently.
    1109     * @since 3.4 Changed signature from min(double[]) to min(double...).
    1110     */
    1111    public static double min(final double... array) {
    1112        // Validates input
    1113        validateArray(array);
    1114        // Finds and returns min
    1115        double min = array[0];
    1116        for (int i = 1; i < array.length; i++) {
    1117            if (Double.isNaN(array[i])) {
    1118                return Double.NaN;
    1119            }
    1120            if (array[i] < min) {
    1121                min = array[i];
    1122            }
    1123        }
    1124        return min;
    1125    }
    1126
    1127    /**
    1128     * Gets the minimum of three {@code double} values.
    1129     *
    1130     * <p>
    1131     * If any value is {@code NaN}, {@code NaN} is returned. Infinity is handled.
    1132     * </p>
    1133     *
    1134     * @param a value 1.
    1135     * @param b value 2.
    1136     * @param c value 3.
    1137     * @return the smallest of the values.
    1138     * @see IEEE754rUtils#min(double, double, double) for a version of this method that handles NaN differently.
    1139     */
    1140    public static double min(final double a, final double b, final double c) {
    1141        return Math.min(Math.min(a, b), c);
    1142    }
    1143
    1144    /**
    1145     * Returns the minimum value in an array.
    1146     *
    1147     * @param array an array, must not be null or empty.
    1148     * @return the minimum value in the array.
    1149     * @throws NullPointerException     if {@code array} is {@code null}.
    1150     * @throws IllegalArgumentException if {@code array} is empty.
    1151     * @see IEEE754rUtils#min(float[]) IEEE754rUtils for a version of this method that handles NaN differently.
    1152     * @since 3.4 Changed signature from min(float[]) to min(float...).
    1153     */
    1154    public static float min(final float... array) {
    1155        // Validates input
    1156        validateArray(array);
    1157        // Finds and returns min
    1158        float min = array[0];
    1159        for (int i = 1; i < array.length; i++) {
    1160            if (Float.isNaN(array[i])) {
    1161                return Float.NaN;
    1162            }
    1163            if (array[i] < min) {
    1164                min = array[i];
    1165            }
    1166        }
    1167        return min;
    1168    }
    1169
    1170    /**
    1171     * Gets the minimum of three {@code float} values.
    1172     *
    1173     * <p>
    1174     * If any value is {@code NaN}, {@code NaN} is returned. Infinity is handled.
    1175     * </p>
    1176     *
    1177     * @param a value 1.
    1178     * @param b value 2.
    1179     * @param c value 3.
    1180     * @return the smallest of the values.
    1181     * @see IEEE754rUtils#min(float, float, float) for a version of this method that handles NaN differently.
    1182     */
    1183    public static float min(final float a, final float b, final float c) {
    1184        return Math.min(Math.min(a, b), c);
    1185    }
    1186
    1187    /**
    1188     * Returns the minimum value in an array.
    1189     *
    1190     * @param array an array, must not be null or empty.
    1191     * @return the minimum value in the array.
    1192     * @throws NullPointerException     if {@code array} is {@code null}.
    1193     * @throws IllegalArgumentException if {@code array} is empty.
    1194     * @since 3.4 Changed signature from min(int[]) to min(int...).
    1195     */
    1196    public static int min(final int... array) {
    1197        // Validates input
    1198        validateArray(array);
    1199        // Finds and returns min
    1200        int min = array[0];
    1201        for (int j = 1; j < array.length; j++) {
    1202            if (array[j] < min) {
    1203                min = array[j];
    1204            }
    1205        }
    1206        return min;
    1207    }
    1208
    1209    /**
    1210     * Gets the minimum of three {@code int} values.
    1211     *
    1212     * @param a value 1.
    1213     * @param b value 2.
    1214     * @param c value 3.
    1215     * @return the smallest of the values.
    1216     */
    1217    public static int min(int a, final int b, final int c) {
    1218        if (b < a) {
    1219            a = b;
    1220        }
    1221        if (c < a) {
    1222            a = c;
    1223        }
    1224        return a;
    1225    }
    1226
    1227    /**
    1228     * Returns the minimum value in an array.
    1229     *
    1230     * @param array an array, must not be null or empty.
    1231     * @return the minimum value in the array.
    1232     * @throws NullPointerException     if {@code array} is {@code null}.
    1233     * @throws IllegalArgumentException if {@code array} is empty.
    1234     * @since 3.4 Changed signature from min(long[]) to min(long...).
    1235     */
    1236    public static long min(final long... array) {
    1237        // Validates input
    1238        validateArray(array);
    1239        // Finds and returns min
    1240        long min = array[0];
    1241        for (int i = 1; i < array.length; i++) {
    1242            if (array[i] < min) {
    1243                min = array[i];
    1244            }
    1245        }
    1246        return min;
    1247    }
    1248
    1249    // 3 param min
    1250    /**
    1251     * Gets the minimum of three {@code long} values.
    1252     *
    1253     * @param a value 1.
    1254     * @param b value 2.
    1255     * @param c value 3.
    1256     * @return the smallest of the values.
    1257     */
    1258    public static long min(long a, final long b, final long c) {
    1259        if (b < a) {
    1260            a = b;
    1261        }
    1262        if (c < a) {
    1263            a = c;
    1264        }
    1265        return a;
    1266    }
    1267
    1268    /**
    1269     * Returns the minimum value in an array.
    1270     *
    1271     * @param array an array, must not be null or empty.
    1272     * @return the minimum value in the array.
    1273     * @throws NullPointerException     if {@code array} is {@code null}.
    1274     * @throws IllegalArgumentException if {@code array} is empty.
    1275     * @since 3.4 Changed signature from min(short[]) to min(short...).
    1276     */
    1277    public static short min(final short... array) {
    1278        // Validates input
    1279        validateArray(array);
    1280        // Finds and returns min
    1281        short min = array[0];
    1282        for (int i = 1; i < array.length; i++) {
    1283            if (array[i] < min) {
    1284                min = array[i];
    1285            }
    1286        }
    1287        return min;
    1288    }
    1289
    1290    /**
    1291     * Gets the minimum of three {@code short} values.
    1292     *
    1293     * @param a value 1.
    1294     * @param b value 2.
    1295     * @param c value 3.
    1296     * @return the smallest of the values.
    1297     */
    1298    public static short min(short a, final short b, final short c) {
    1299        if (b < a) {
    1300            a = b;
    1301        }
    1302        if (c < a) {
    1303            a = c;
    1304        }
    1305        return a;
    1306    }
    1307
    1308    /**
    1309     * Converts a {@link String} to a {@code byte}, returning {@code zero} if the conversion fails.
    1310     *
    1311     * <p>
    1312     * If the string is {@code null}, {@code zero} is returned.
    1313     * </p>
    1314     *
    1315     * <pre>
    1316     *   NumberUtils.toByte(null) = 0
    1317     *   NumberUtils.toByte("")   = 0
    1318     *   NumberUtils.toByte("1")  = 1
    1319     * </pre>
    1320     *
    1321     * @param str the string to convert, may be null.
    1322     * @return the byte represented by the string, or {@code zero} if conversion fails.
    1323     * @since 2.5
    1324     */
    1325    public static byte toByte(final String str) {
    1326        return toByte(str, (byte) 0);
    1327    }
    1328
    1329    /**
    1330     * Converts a {@link String} to a {@code byte}, returning a default value if the conversion fails.
    1331     *
    1332     * <p>
    1333     * If the string is {@code null}, the default value is returned.
    1334     * </p>
    1335     *
    1336     * <pre>
    1337     *   NumberUtils.toByte(null, 1) = 1
    1338     *   NumberUtils.toByte("", 1)   = 1
    1339     *   NumberUtils.toByte("1", 0)  = 1
    1340     * </pre>
    1341     *
    1342     * @param str          the string to convert, may be null.
    1343     * @param defaultValue the default value.
    1344     * @return the byte represented by the string, or the default if conversion fails.
    1345     * @since 2.5
    1346     */
    1347    public static byte toByte(final String str, final byte defaultValue) {
    1348        try {
    1349            return Byte.parseByte(str);
    1350        } catch (final RuntimeException e) {
    1351            return defaultValue;
    1352        }
    1353    }
    1354
    1355    /**
    1356     * Converts a {@link BigDecimal} to a {@code double}.
    1357     *
    1358     * <p>
    1359     * If the {@link BigDecimal} {@code value} is {@code null}, then the specified default value is returned.
    1360     * </p>
    1361     *
    1362     * <pre>
    1363     *   NumberUtils.toDouble(null)                     = 0.0d
    1364     *   NumberUtils.toDouble(BigDecimal.valueOf(8.5d)) = 8.5d
    1365     * </pre>
    1366     *
    1367     * @param value the {@link BigDecimal} to convert, may be {@code null}.
    1368     * @return the double represented by the {@link BigDecimal} or {@code 0.0d} if the {@link BigDecimal} is {@code null}.
    1369     * @since 3.8
    1370     */
    1371    public static double toDouble(final BigDecimal value) {
    1372        return toDouble(value, 0.0d);
    1373    }
    1374
    1375    /**
    1376     * Converts a {@link BigDecimal} to a {@code double}.
    1377     *
    1378     * <p>
    1379     * If the {@link BigDecimal} {@code value} is {@code null}, then the specified default value is returned.
    1380     * </p>
    1381     *
    1382     * <pre>
    1383     *   NumberUtils.toDouble(null, 1.1d)                     = 1.1d
    1384     *   NumberUtils.toDouble(BigDecimal.valueOf(8.5d), 1.1d) = 8.5d
    1385     * </pre>
    1386     *
    1387     * @param value        the {@link BigDecimal} to convert, may be {@code null}.
    1388     * @param defaultValue the default value.
    1389     * @return the double represented by the {@link BigDecimal} or the defaultValue if the {@link BigDecimal} is {@code null}.
    1390     * @since 3.8
    1391     */
    1392    public static double toDouble(final BigDecimal value, final double defaultValue) {
    1393        return value == null ? defaultValue : value.doubleValue();
    1394    }
    1395
    1396    /**
    1397     * Converts a {@link String} to a {@code double}, returning {@code 0.0d} if the conversion fails.
    1398     *
    1399     * <p>
    1400     * If the string {@code str} is {@code null}, {@code 0.0d} is returned.
    1401     * </p>
    1402     *
    1403     * <pre>
    1404     *   NumberUtils.toDouble(null)   = 0.0d
    1405     *   NumberUtils.toDouble("")     = 0.0d
    1406     *   NumberUtils.toDouble("1.5")  = 1.5d
    1407     * </pre>
    1408     *
    1409     * @param str the string to convert, may be {@code null}.
    1410     * @return the double represented by the string, or {@code 0.0d} if conversion fails.
    1411     * @since 2.1
    1412     */
    1413    public static double toDouble(final String str) {
    1414        return toDouble(str, 0.0d);
    1415    }
    1416
    1417    /**
    1418     * Converts a {@link String} to a {@code double}, returning a default value if the conversion fails.
    1419     *
    1420     * <p>
    1421     * If the string {@code str} is {@code null}, the default value is returned.
    1422     * </p>
    1423     *
    1424     * <pre>
    1425     *   NumberUtils.toDouble(null, 1.1d)   = 1.1d
    1426     *   NumberUtils.toDouble("", 1.1d)     = 1.1d
    1427     *   NumberUtils.toDouble("1.5", 0.0d)  = 1.5d
    1428     * </pre>
    1429     *
    1430     * @param str          the string to convert, may be {@code null}
    1431     * @param defaultValue the default value.
    1432     * @return the double represented by the string, or defaultValue if conversion fails.
    1433     * @since 2.1
    1434     */
    1435    public static double toDouble(final String str, final double defaultValue) {
    1436        try {
    1437            return Double.parseDouble(str);
    1438        } catch (final RuntimeException e) {
    1439            return defaultValue;
    1440        }
    1441    }
    1442
    1443    /**
    1444     * Converts a {@link String} to a {@code float}, returning {@code 0.0f} if the conversion fails.
    1445     *
    1446     * <p>
    1447     * If the string {@code str} is {@code null}, {@code 0.0f} is returned.
    1448     * </p>
    1449     *
    1450     * <pre>
    1451     *   NumberUtils.toFloat(null)   = 0.0f
    1452     *   NumberUtils.toFloat("")     = 0.0f
    1453     *   NumberUtils.toFloat("1.5")  = 1.5f
    1454     * </pre>
    1455     *
    1456     * @param str the string to convert, may be {@code null}.
    1457     * @return the float represented by the string, or {@code 0.0f} if conversion fails.
    1458     * @since 2.1
    1459     */
    1460    public static float toFloat(final String str) {
    1461        return toFloat(str, 0.0f);
    1462    }
    1463
    1464    /**
    1465     * Converts a {@link String} to a {@code float}, returning a default value if the conversion fails.
    1466     *
    1467     * <p>
    1468     * If the string {@code str} is {@code null}, the default value is returned.
    1469     * </p>
    1470     *
    1471     * <pre>
    1472     *   NumberUtils.toFloat(null, 1.1f)   = 1.1f
    1473     *   NumberUtils.toFloat("", 1.1f)     = 1.1f
    1474     *   NumberUtils.toFloat("1.5", 0.0f)  = 1.5f
    1475     * </pre>
    1476     *
    1477     * @param str          the string to convert, may be {@code null}.
    1478     * @param defaultValue the default value.
    1479     * @return the float represented by the string, or defaultValue if conversion fails.
    1480     * @since 2.1
    1481     */
    1482    public static float toFloat(final String str, final float defaultValue) {
    1483        try {
    1484            return Float.parseFloat(str);
    1485        } catch (final RuntimeException e) {
    1486            return defaultValue;
    1487        }
    1488    }
    1489
    1490    /**
    1491     * Converts a {@link String} to an {@code int}, returning {@code zero} if the conversion fails.
    1492     *
    1493     * <p>
    1494     * If the string is {@code null}, {@code zero} is returned.
    1495     * </p>
    1496     *
    1497     * <pre>
    1498     *   NumberUtils.toInt(null) = 0
    1499     *   NumberUtils.toInt("")   = 0
    1500     *   NumberUtils.toInt("1")  = 1
    1501     * </pre>
    1502     *
    1503     * @param str the string to convert, may be null.
    1504     * @return the int represented by the string, or {@code zero} if conversion fails.
    1505     * @since 2.1
    1506     */
    1507    public static int toInt(final String str) {
    1508        return toInt(str, 0);
    1509    }
    1510
    1511    /**
    1512     * Converts a {@link String} to an {@code int}, returning a default value if the conversion fails.
    1513     *
    1514     * <p>
    1515     * If the string is {@code null}, the default value is returned.
    1516     * </p>
    1517     *
    1518     * <pre>
    1519     *   NumberUtils.toInt(null, 1) = 1
    1520     *   NumberUtils.toInt("", 1)   = 1
    1521     *   NumberUtils.toInt("1", 0)  = 1
    1522     * </pre>
    1523     *
    1524     * @param str          the string to convert, may be null.
    1525     * @param defaultValue the default value.
    1526     * @return the int represented by the string, or the default if conversion fails.
    1527     * @since 2.1
    1528     */
    1529    public static int toInt(final String str, final int defaultValue) {
    1530        try {
    1531            return Integer.parseInt(str);
    1532        } catch (final RuntimeException e) {
    1533            return defaultValue;
    1534        }
    1535    }
    1536
    1537    /**
    1538     * Converts a {@link String} to a {@code long}, returning {@code zero} if the conversion fails.
    1539     *
    1540     * <p>
    1541     * If the string is {@code null}, {@code zero} is returned.
    1542     * </p>
    1543     *
    1544     * <pre>
    1545     *   NumberUtils.toLong(null) = 0L
    1546     *   NumberUtils.toLong("")   = 0L
    1547     *   NumberUtils.toLong("1")  = 1L
    1548     * </pre>
    1549     *
    1550     * @param str the string to convert, may be null.
    1551     * @return the long represented by the string, or {@code 0} if conversion fails.
    1552     * @since 2.1
    1553     */
    1554    public static long toLong(final String str) {
    1555        return toLong(str, 0L);
    1556    }
    1557
    1558    /**
    1559     * Converts a {@link String} to a {@code long}, returning a default value if the conversion fails.
    1560     *
    1561     * <p>
    1562     * If the string is {@code null}, the default value is returned.
    1563     * </p>
    1564     *
    1565     * <pre>
    1566     *   NumberUtils.toLong(null, 1L) = 1L
    1567     *   NumberUtils.toLong("", 1L)   = 1L
    1568     *   NumberUtils.toLong("1", 0L)  = 1L
    1569     * </pre>
    1570     *
    1571     * @param str          the string to convert, may be null.
    1572     * @param defaultValue the default value.
    1573     * @return the long represented by the string, or the default if conver sion fails.
    1574     * @since 2.1
    1575     */
    1576    public static long toLong(final String str, final long defaultValue) {
    1577        try {
    1578            return Long.parseLong(str);
    1579        } catch (final RuntimeException e) {
    1580            return defaultValue;
    1581        }
    1582    }
    1583
    1584    /**
    1585     * Converts a {@link BigDecimal} to a {@link BigDecimal} with a scale of two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
    1586     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
    1587     *
    1588     * <p>
    1589     * Note, the scale of a {@link BigDecimal} is the number of digits to the right of the decimal point.
    1590     * </p>
    1591     *
    1592     * @param value the {@link BigDecimal} to convert, may be null.
    1593     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1594     * @since 3.8
    1595     */
    1596    public static BigDecimal toScaledBigDecimal(final BigDecimal value) {
    1597        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
    1598    }
    1599
    1600    /**
    1601     * Converts a {@link BigDecimal} to a {@link BigDecimal} whose scale is the specified value with a {@link RoundingMode} applied. If the input {@code value}
    1602     * is {@code null}, we simply return {@code BigDecimal.ZERO}.
    1603     *
    1604     * @param value        the {@link BigDecimal} to convert, may be null.
    1605     * @param scale        the number of digits to the right of the decimal point.
    1606     * @param roundingMode a rounding behavior for numerical operations capable of discarding precision.
    1607     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1608     * @since 3.8
    1609     */
    1610    public static BigDecimal toScaledBigDecimal(final BigDecimal value, final int scale, final RoundingMode roundingMode) {
    1611        if (value == null) {
    1612            return BigDecimal.ZERO;
    1613        }
    1614        return value.setScale(scale, roundingMode == null ? RoundingMode.HALF_EVEN : roundingMode);
    1615    }
    1616
    1617    /**
    1618     * Converts a {@link Double} to a {@link BigDecimal} with a scale of two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
    1619     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
    1620     *
    1621     * <p>
    1622     * Note, the scale of a {@link BigDecimal} is the number of digits to the right of the decimal point.
    1623     * </p>
    1624     *
    1625     * @param value the {@link Double} to convert, may be null.
    1626     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1627     * @since 3.8
    1628     */
    1629    public static BigDecimal toScaledBigDecimal(final Double value) {
    1630        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
    1631    }
    1632
    1633    /**
    1634     * Converts a {@link Double} to a {@link BigDecimal} whose scale is the specified value with a {@link RoundingMode} applied. If the input {@code value} is
    1635     * {@code null}, we simply return {@code BigDecimal.ZERO}.
    1636     *
    1637     * @param value        the {@link Double} to convert, may be null.
    1638     * @param scale        the number of digits to the right of the decimal point.
    1639     * @param roundingMode a rounding behavior for numerical operations capable of discarding precision.
    1640     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1641     * @since 3.8
    1642     */
    1643    public static BigDecimal toScaledBigDecimal(final Double value, final int scale, final RoundingMode roundingMode) {
    1644        if (value == null) {
    1645            return BigDecimal.ZERO;
    1646        }
    1647        return toScaledBigDecimal(BigDecimal.valueOf(value), scale, roundingMode);
    1648    }
    1649
    1650    /**
    1651     * Converts a {@link Float} to a {@link BigDecimal} with a scale of two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
    1652     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
    1653     *
    1654     * <p>
    1655     * Note, the scale of a {@link BigDecimal} is the number of digits to the right of the decimal point.
    1656     * </p>
    1657     *
    1658     * @param value the {@link Float} to convert, may be null.
    1659     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1660     * @since 3.8
    1661     */
    1662    public static BigDecimal toScaledBigDecimal(final Float value) {
    1663        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
    1664    }
    1665
    1666    /**
    1667     * Converts a {@link Float} to a {@link BigDecimal} whose scale is the specified value with a {@link RoundingMode} applied. If the input {@code value} is
    1668     * {@code null}, we simply return {@code BigDecimal.ZERO}.
    1669     *
    1670     * @param value        the {@link Float} to convert, may be null.
    1671     * @param scale        the number of digits to the right of the decimal point.
    1672     * @param roundingMode a rounding behavior for numerical operations capable of discarding precision.
    1673     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1674     * @since 3.8
    1675     */
    1676    public static BigDecimal toScaledBigDecimal(final Float value, final int scale, final RoundingMode roundingMode) {
    1677        if (value == null) {
    1678            return BigDecimal.ZERO;
    1679        }
    1680        return toScaledBigDecimal(BigDecimal.valueOf(value), scale, roundingMode);
    1681    }
    1682
    1683    /**
    1684     * Converts a {@link String} to a {@link BigDecimal} with a scale of two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
    1685     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
    1686     *
    1687     * <p>
    1688     * Note, the scale of a {@link BigDecimal} is the number of digits to the right of the decimal point.
    1689     * </p>
    1690     *
    1691     * @param value the {@link String} to convert, may be null.
    1692     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1693     * @since 3.8
    1694     */
    1695    public static BigDecimal toScaledBigDecimal(final String value) {
    1696        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
    1697    }
    1698
    1699    /**
    1700     * Converts a {@link String} to a {@link BigDecimal} whose scale is the specified value with a {@link RoundingMode} applied. If the input {@code value} is
    1701     * {@code null}, we simply return {@code BigDecimal.ZERO}.
    1702     *
    1703     * @param value        the {@link String} to convert, may be null.
    1704     * @param scale        the number of digits to the right of the decimal point.
    1705     * @param roundingMode a rounding behavior for numerical operations capable of discarding precision.
    1706     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1707     * @since 3.8
    1708     */
    1709    public static BigDecimal toScaledBigDecimal(final String value, final int scale, final RoundingMode roundingMode) {
    1710        if (value == null) {
    1711            return BigDecimal.ZERO;
    1712        }
    1713        return toScaledBigDecimal(createBigDecimal(value), scale, roundingMode);
    1714    }
    1715
    1716    /**
    1717     * Converts a {@link String} to a {@code short}, returning {@code zero} if the conversion fails.
    1718     *
    1719     * <p>
    1720     * If the string is {@code null}, {@code zero} is returned.
    1721     * </p>
    1722     *
    1723     * <pre>
    1724     *   NumberUtils.toShort(null) = 0
    1725     *   NumberUtils.toShort("")   = 0
    1726     *   NumberUtils.toShort("1")  = 1
    1727     * </pre>
    1728     *
    1729     * @param str the string to convert, may be null.
    1730     * @return the short represented by the string, or {@code zero} if conversion fails.
    1731     * @since 2.5
    1732     */
    1733    public static short toShort(final String str) {
    1734        return toShort(str, (short) 0);
    1735    }
    1736
    1737    /**
    1738     * Converts a {@link String} to an {@code short}, returning a default value if the conversion fails.
    1739     *
    1740     * <p>
    1741     * If the string is {@code null}, the default value is returned.
    1742     * </p>
    1743     *
    1744     * <pre>
    1745     *   NumberUtils.toShort(null, 1) = 1
    1746     *   NumberUtils.toShort("", 1)   = 1
    1747     *   NumberUtils.toShort("1", 0)  = 1
    1748     * </pre>
    1749     *
    1750     * @param str          the string to convert, may be null.
    1751     * @param defaultValue the default value.
    1752     * @return the short represented by the string, or the default if conversion fails.
    1753     * @since 2.5
    1754     */
    1755    public static short toShort(final String str, final short defaultValue) {
    1756        try {
    1757            return Short.parseShort(str);
    1758        } catch (final RuntimeException e) {
    1759            return defaultValue;
    1760        }
    1761    }
    1762
    1763    /**
    1764     * Checks if the specified array is neither null nor empty.
    1765     *
    1766     * @param array the array to check.
    1767     * @throws IllegalArgumentException if {@code array} is empty.
    1768     * @throws NullPointerException     if {@code array} is {@code null}.
    1769     */
    1770    private static void validateArray(final Object array) {
    1771        Objects.requireNonNull(array, "array");
    1772        Validate.isTrue(Array.getLength(array) != 0, "Array cannot be empty.");
    1773    }
    1774
    1775    private static boolean withDecimalsParsing(final String str, final int beginIdx) {
    1776        int decimalPoints = 0;
    1777        for (int i = beginIdx; i < str.length(); i++) {
    1778            final char ch = str.charAt(i);
    1779            final boolean isDecimalPoint = ch == '.';
    1780            if (isDecimalPoint) {
    1781                decimalPoints++;
    1782            }
    1783            if (decimalPoints > 1) {
    1784                return false;
    1785            }
    1786            if (!isDecimalPoint && !Character.isDigit(ch)) {
    1787                return false;
    1788            }
    1789        }
    1790        return true;
    1791    }
    1792
    1793    /**
    1794     * {@link NumberUtils} instances should NOT be constructed in standard programming. Instead, the class should be used as {@code NumberUtils.toInt("6");}.
    1795     *
    1796     * <p>
    1797     * This constructor is public to permit tools that require a JavaBean instance to operate.
    1798     * </p>
    1799     *
    1800     * @deprecated TODO Make private in 4.0.
    1801     */
    1802    @Deprecated
    1803    public NumberUtils() {
    1804        // empty
    1805    }
    1806}