    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};
    095     *         a value less than {@code 0} if {@code x < y}; and
    096     *         a value greater than {@code 0} if {@code x > y}
    097     * @since 3.4
    098     */
    099    public static int compare(final byte x, final byte y) {
    100        return 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};
    109     *         a value less than {@code 0} if {@code x < y}; and
    110     *         a value greater than {@code 0} if {@code x > y}
    111     * @since 3.4
    112     */
    113    public static int compare(final int x, final int y) {
    114        if (x == y) {
    115            return 0;
    116        }
    117        return x < y ? -1 : 1;
    118    }
    119
    120    /**
    121     * Compares to {@code long} values numerically. This is the same functionality as provided in Java 7.
    122     *
    123     * @param x the first {@code long} to compare
    124     * @param y the second {@code long} to compare
    125     * @return the value {@code 0} if {@code x == y};
    126     *         a value less than {@code 0} if {@code x < y}; and
    127     *         a value greater than {@code 0} if {@code x > y}
    128     * @since 3.4
    129     */
    130    public static int compare(final long x, final long y) {
    131        if (x == y) {
    132            return 0;
    133        }
    134        return x < y ? -1 : 1;
    135    }
    136
    137    /**
    138     * Compares to {@code short} values numerically. This is the same functionality as provided in Java 7.
    139     *
    140     * @param x the first {@code short} to compare
    141     * @param y the second {@code short} to compare
    142     * @return the value {@code 0} if {@code x == y};
    143     *         a value less than {@code 0} if {@code x < y}; and
    144     *         a value greater than {@code 0} if {@code x > y}
    145     * @since 3.4
    146     */
    147    public static int compare(final short x, final short y) {
    148        if (x == y) {
    149            return 0;
    150        }
    151        return x < y ? -1 : 1;
    152    }
    153
    154    /**
    155     * Creates a {@link BigDecimal} from a {@link String}.
    156     *
    157     * <p>Returns {@code null} if the string is {@code null}.</p>
    158     *
    159     * @param str  a {@link String} to convert, may be null
    160     * @return converted {@link BigDecimal} (or null if the input is null)
    161     * @throws NumberFormatException if the value cannot be converted
    162     */
    163    public static BigDecimal createBigDecimal(final String str) {
    164        if (str == null) {
    165            return null;
    166        }
    167        // handle JDK1.3.1 bug where "" throws IndexOutOfBoundsException
    168        if (StringUtils.isBlank(str)) {
    169            throw new NumberFormatException("A blank string is not a valid number");
    170        }
    171        return new BigDecimal(str);
    172    }
    173
    174    /**
    175     * Creates a {@link BigInteger} from a {@link String}.
    176     *
    177     * Handles hexadecimal (0x or #) and octal (0) notations.
    178     *
    179     * <p>Returns {@code null} if the string is {@code null}.</p>
    180     *
    181     * @param str  a {@link String} to convert, may be null
    182     * @return converted {@link BigInteger} (or null if the input is null)
    183     * @throws NumberFormatException if the value cannot be converted
    184     * @since 3.2
    185     */
    186    public static BigInteger createBigInteger(final String str) {
    187        if (str == null) {
    188            return null;
    189        }
    190        if (str.isEmpty()) {
    191            throw new NumberFormatException("An empty string is not a valid number");
    192        }
    193        int pos = 0; // offset within string
    194        int radix = 10;
    195        boolean negate = false; // need to negate later?
    196        final char char0 = str.charAt(0);
    197        if (char0 == '-') {
    198            negate = true;
    199            pos = 1;
    200        } else if (char0 == '+') {
    201            pos = 1;
    202        }
    203        if (str.startsWith("0x", pos) || str.startsWith("0X", pos)) { // hex
    204            radix = 16;
    205            pos += 2;
    206        } else if (str.startsWith("#", pos)) { // alternative hex (allowed by Long/Integer)
    207            radix = 16;
    208            pos++;
    209        } else if (str.startsWith("0", pos) && str.length() > pos + 1) { // octal; so long as there are additional digits
    210            radix = 8;
    211            pos++;
    212        } // default is to treat as decimal
    213
    214        final BigInteger value = new BigInteger(str.substring(pos), radix);
    215        return negate ? value.negate() : value;
    216    }
    217
    218    /**
    219     * Creates a {@link Double} from a {@link String}.
    220     *
    221     * <p>Returns {@code null} if the string is {@code null}.</p>
    222     *
    223     * @param str  a {@link String} to convert, may be null
    224     * @return converted {@link Double} (or null if the input is null)
    225     * @throws NumberFormatException if the value cannot be converted
    226     */
    227    public static Double createDouble(final String str) {
    228        if (str == null) {
    229            return null;
    230        }
    231        return Double.valueOf(str);
    232    }
    233
    234    /**
    235     * Creates a {@link Float} from a {@link String}.
    236     *
    237     * <p>Returns {@code null} if the string is {@code null}.</p>
    238     *
    239     * @param str  a {@link String} to convert, may be null
    240     * @return converted {@link Float} (or null if the input is null)
    241     * @throws NumberFormatException if the value cannot be converted
    242     */
    243    public static Float createFloat(final String str) {
    244        if (str == null) {
    245            return null;
    246        }
    247        return Float.valueOf(str);
    248    }
    249
    250    /**
    251     * Creates an {@link Integer} from a {@link String}.
    252     *
    253     * Handles hexadecimal (0xhhhh) and octal (0dddd) notations.
    254     * A leading zero means octal; spaces are not trimmed.
    255     *
    256     * <p>Returns {@code null} if the string is {@code null}.</p>
    257     *
    258     * @param str  a {@link String} to convert, may be null
    259     * @return converted {@link Integer} (or null if the input is null)
    260     * @throws NumberFormatException if the value cannot be converted
    261     */
    262    public static Integer createInteger(final String str) {
    263        if (str == null) {
    264            return null;
    265        }
    266        // decode() handles 0xAABD and 0777 (hex and octal) as well.
    267        return Integer.decode(str);
    268    }
    269
    270    /**
    271     * Creates a {@link Long} from a {@link String}.
    272     *
    273     * Handles hexadecimal (0Xhhhh) and octal (0ddd) notations.
    274     * A leading zero means octal; spaces are not trimmed.
    275     *
    276     * <p>Returns {@code null} if the string is {@code null}.</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>If the string starts with {@code 0x} or {@code -0x} (lower or upper case) or {@code #} or {@code -#}, it
    294     * will be interpreted as a hexadecimal Integer - or Long, if the number of digits after the
    295     * prefix is more than 8 - or BigInteger if there are more than 16 digits.
    296     * </p>
    297     * <p>Then, the value is examined for a type qualifier on the end, i.e. one of
    298     * {@code 'f', 'F', 'd', 'D', 'l', 'L'}.  If it is found, it starts
    299     * trying to create successively larger types from the type specified
    300     * until one is found that can represent the value.</p>
    301     *
    302     * <p>If a type specifier is not found, it will check for a decimal point
    303     * and then try successively larger types from {@link Integer} to
    304     * {@link BigInteger} and from {@link Float} to
    305     * {@link BigDecimal}.</p>
    306     *
    307     * <p>
    308     * Integral values with a leading {@code 0} will be interpreted as octal; the returned number will
    309     * be Integer, Long or BigDecimal as appropriate.
    310     * </p>
    311     *
    312     * <p>Returns {@code null} if the string is {@code null}.</p>
    313     *
    314     * <p>This method does not trim the input string, i.e., strings with leading
    315     * or trailing spaces will generate NumberFormatExceptions.</p>
    316     *
    317     * @param str  String containing a number, may be null
    318     * @return Number created from the string (or null if the input is null)
    319     * @throws NumberFormatException if the value cannot be converted
    320     */
    321    public static Number createNumber(final String str) {
    322        if (str == null) {
    323            return null;
    324        }
    325        if (StringUtils.isBlank(str)) {
    326            throw new NumberFormatException("A blank string is not a valid number");
    327        }
    328        // Need to deal with all possible hex prefixes here
    329        final String[] hexPrefixes = {"0x", "0X", "#"};
    330        final int length = str.length();
    331        final int offset = isSign(str.charAt(0)) ? 1 : 0;
    332        int pfxLen = 0;
    333        for (final String pfx : hexPrefixes) {
    334            if (str.startsWith(pfx, offset)) {
    335                pfxLen += pfx.length() + offset;
    336                break;
    337            }
    338        }
    339        if (pfxLen > 0) { // we have a hex number
    340            char firstSigDigit = 0; // strip leading zeroes
    341            for (int i = pfxLen; i < length; i++) {
    342                firstSigDigit = str.charAt(i);
    343                if (firstSigDigit != '0') {
    344                    break;
    345                }
    346                pfxLen++;
    347            }
    348            final int hexDigits = length - pfxLen;
    349            if (hexDigits > 16 || hexDigits == 16 && firstSigDigit > '7') { // too many for Long
    350                return createBigInteger(str);
    351            }
    352            if (hexDigits > 8 || hexDigits == 8 && firstSigDigit > '7') { // too many for an int
    353                return createLong(str);
    354            }
    355            return createInteger(str);
    356        }
    357        final char lastChar = str.charAt(length - 1);
    358        final String mant;
    359        final String dec;
    360        final String exp;
    361        final int decPos = str.indexOf('.');
    362        final int expPos = str.indexOf('e') + str.indexOf('E') + 1; // assumes both not present
    363        // if both e and E are present, this is caught by the checks on expPos (which prevent IOOBE)
    364        // and the parsing which will detect if e or E appear in a number due to using the wrong offset
    365
    366        // Detect if the return type has been requested
    367        final boolean requestType = !Character.isDigit(lastChar) && lastChar != '.';
    368        if (decPos > -1) { // there is a decimal point
    369            if (expPos > -1) { // there is an exponent
    370                if (expPos <= decPos || expPos > length) { // prevents double exponent causing IOOBE
    371                    throw new NumberFormatException(str + " is not a valid number.");
    372                }
    373                dec = str.substring(decPos + 1, expPos);
    374            } else {
    375                // No exponent, but there may be a type character to remove
    376                dec = str.substring(decPos + 1, requestType ? length - 1 : length);
    377            }
    378            mant = getMantissa(str, decPos);
    379        } else {
    380            if (expPos > -1) {
    381                if (expPos > length) { // prevents double exponent causing IOOBE
    382                    throw new NumberFormatException(str + " is not a valid number.");
    383                }
    384                mant = getMantissa(str, expPos);
    385            } else {
    386                // No decimal, no exponent, but there may be a type character to remove
    387                mant = getMantissa(str, requestType ? length - 1 : length);
    388            }
    389            dec = null;
    390        }
    391        if (requestType) {
    392            if (expPos > -1 && expPos < length - 1) {
    393                exp = str.substring(expPos + 1, length - 1);
    394            } else {
    395                exp = null;
    396            }
    397            //Requesting a specific type.
    398            final String numeric = str.substring(0, length - 1);
    399            switch (lastChar) {
    400                case 'l' :
    401                case 'L' :
    402                    if (dec == null
    403                        && exp == null
    404                        && (!numeric.isEmpty() && numeric.charAt(0) == '-' && isDigits(numeric.substring(1)) || isDigits(numeric))) {
    405                        try {
    406                            return createLong(numeric);
    407                        } catch (final NumberFormatException ignored) {
    408                            // Too big for a long
    409                        }
    410                        return createBigInteger(numeric);
    411
    412                    }
    413                    throw new NumberFormatException(str + " is not a valid number.");
    414                case 'f' :
    415                case 'F' :
    416                    try {
    417                        final Float f = createFloat(str);
    418                        if (!(f.isInfinite() || f.floatValue() == 0.0F && !isZero(mant, dec))) {
    419                            //If it's too big for a float or the float value = 0 and the string
    420                            //has non-zeros in it, then float does not have the precision we want
    421                            return f;
    422                        }
    423
    424                    } catch (final NumberFormatException ignored) {
    425                        // ignore the bad number
    426                    }
    427                    // falls-through
    428                case 'd' :
    429                case 'D' :
    430                    try {
    431                        final Double d = createDouble(str);
    432                        if (!(d.isInfinite() || d.doubleValue() == 0.0D && !isZero(mant, dec))) {
    433                            return d;
    434                        }
    435                    } catch (final NumberFormatException ignored) {
    436                        // ignore the bad number
    437                    }
    438                    try {
    439                        return createBigDecimal(numeric);
    440                    } catch (final NumberFormatException ignored) {
    441                        // ignore the bad number
    442                    }
    443                    // falls-through
    444                default :
    445                    throw new NumberFormatException(str + " is not a valid number.");
    446
    447            }
    448        }
    449        //User doesn't have a preference on the return type, so let's start
    450        //small and go from there...
    451        if (expPos > -1 && expPos < length - 1) {
    452            exp = str.substring(expPos + 1);
    453        } else {
    454            exp = null;
    455        }
    456        if (dec == null && exp == null) { // no decimal point and no exponent
    457            //Must be an Integer, Long, Biginteger
    458            try {
    459                return createInteger(str);
    460            } catch (final NumberFormatException ignored) {
    461                // ignore the bad number
    462            }
    463            try {
    464                return createLong(str);
    465            } catch (final NumberFormatException ignored) {
    466                // ignore the bad number
    467            }
    468            return createBigInteger(str);
    469        }
    470
    471        //Must be a Float, Double, BigDecimal
    472        try {
    473            final Float f = createFloat(str);
    474            final Double d = createDouble(str);
    475            if (!f.isInfinite()
    476                    && !(f.floatValue() == 0.0F && !isZero(mant, dec))
    477                    && f.toString().equals(d.toString())) {
    478                return f;
    479            }
    480            if (!d.isInfinite() && !(d.doubleValue() == 0.0D && !isZero(mant, dec))) {
    481                final BigDecimal b = createBigDecimal(str);
    482                if (b.compareTo(BigDecimal.valueOf(d.doubleValue())) == 0) {
    483                    return d;
    484                }
    485                return b;
    486            }
    487        } catch (final NumberFormatException ignored) {
    488            // ignore the bad number
    489        }
    490        return createBigDecimal(str);
    491    }
    492
    493     /**
    494     * Utility method for {@link #createNumber(String)}.
    495     *
    496     * <p>Returns mantissa of the given number.</p>
    497     *
    498     * @param str the string representation of the number
    499     * @param stopPos the position of the exponent or decimal point
    500     * @return mantissa of the given number
    501     * @throws NumberFormatException if no mantissa can be retrieved
    502     */
    503    private static String getMantissa(final String str, final int stopPos) {
    504         final char firstChar = str.charAt(0);
    505         final boolean hasSign = isSign(firstChar);
    506         final int length = str.length();
    507         if (length <= (hasSign ? 1 : 0) || length < stopPos) {
    508             throw new NumberFormatException(str + " is not a valid number.");
    509         }
    510         return hasSign ? str.substring(1, stopPos) : str.substring(0, stopPos);
    511    }
    512
    513     /**
    514     * Utility method for {@link #createNumber(java.lang.String)}.
    515     *
    516     * <p>Returns {@code true} if s is {@code null} or empty.</p>
    517     *
    518     * @param str the String to check
    519     * @return if it is all zeros or {@code null}
    520     */
    521    private static boolean isAllZeros(final String str) {
    522        if (str == null) {
    523            return true;
    524        }
    525        for (int i = str.length() - 1; i >= 0; i--) {
    526            if (str.charAt(i) != '0') {
    527                return false;
    528            }
    529        }
    530        return true;
    531    }
    532
    533    /**
    534     * Checks whether the String is a valid Java number.
    535     *
    536     * <p>Valid numbers include hexadecimal marked with the {@code 0x} or
    537     * {@code 0X} qualifier, octal numbers, scientific notation and
    538     * numbers marked with a type qualifier (e.g. 123L).</p>
    539     *
    540     * <p>Non-hexadecimal strings beginning with a leading zero are
    541     * treated as octal values. Thus the string {@code 09} will return
    542     * {@code false}, since {@code 9} is not a valid octal value.
    543     * However, numbers beginning with {@code 0.} are treated as decimal.</p>
    544     *
    545     * <p>{@code null} and empty/blank {@link String} will return
    546     * {@code false}.</p>
    547     *
    548     * <p>Note, {@link #createNumber(String)} should return a number for every
    549     * input resulting in {@code true}.</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
    602            } else if (chars[i] == '.') {
    603                if (hasDecPoint || hasExp) {
    604                    // two decimal points or dec in exponent
    605                    return false;
    606                }
    607                hasDecPoint = true;
    608            } else if (chars[i] == 'e' || chars[i] == 'E') {
    609                // we've already taken care of hex.
    610                if (hasExp) {
    611                    // two E's
    612                    return false;
    613                }
    614                if (!foundDigit) {
    615                    return false;
    616                }
    617                hasExp = true;
    618                allowSigns = true;
    619            } else if (isSign(chars[i])) {
    620                if (!allowSigns) {
    621                    return false;
    622                }
    623                allowSigns = false;
    624                foundDigit = false; // we need a digit after the E
    625            } else {
    626                return false;
    627            }
    628            i++;
    629        }
    630        if (i < chars.length) {
    631            if (CharUtils.isAsciiNumeric(chars[i])) {
    632                // no type qualifier, OK
    633                return true;
    634            }
    635            if (chars[i] == 'e' || chars[i] == 'E') {
    636                // can't have an E at the last byte
    637                return false;
    638            }
    639            if (chars[i] == '.') {
    640                if (hasDecPoint || hasExp) {
    641                    // two decimal points or dec in exponent
    642                    return false;
    643                }
    644                // single trailing decimal point after non-exponent is ok
    645                return foundDigit;
    646            }
    647            if (!allowSigns
    648                && (chars[i] == 'd'
    649                    || chars[i] == 'D'
    650                    || chars[i] == 'f'
    651                    || chars[i] == 'F')) {
    652                return foundDigit;
    653            }
    654            if (chars[i] == 'l'
    655                || chars[i] == 'L') {
    656                // not allowing L with an exponent or decimal point
    657                return foundDigit && !hasExp && !hasDecPoint;
    658            }
    659            // last character is illegal
    660            return false;
    661        }
    662        // allowSigns is true iff the val ends in 'E'
    663        // found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
    664        return !allowSigns && foundDigit;
    665    }
    666
    667    /**
    668     * Checks whether the {@link String} contains only
    669     * digit characters.
    670     *
    671     * <p>{@code null} and empty String will return
    672     * {@code false}.</p>
    673     *
    674     * @param str  the {@link String} to check
    675     * @return {@code true} if str contains only Unicode numeric
    676     */
    677    public static boolean isDigits(final String str) {
    678        return StringUtils.isNumeric(str);
    679    }
    680
    681    /**
    682     * Checks whether the String is a valid Java number.
    683     *
    684     * <p>Valid numbers include hexadecimal marked with the {@code 0x} or
    685     * {@code 0X} qualifier, octal numbers, scientific notation and
    686     * numbers marked with a type qualifier (e.g. 123L).</p>
    687     *
    688     * <p>Non-hexadecimal strings beginning with a leading zero are
    689     * treated as octal values. Thus the string {@code 09} will return
    690     * {@code false}, since {@code 9} is not a valid octal value.
    691     * However, numbers beginning with {@code 0.} are treated as decimal.</p>
    692     *
    693     * <p>{@code null} and empty/blank {@link String} will return
    694     * {@code false}.</p>
    695     *
    696     * <p>Note, {@link #createNumber(String)} should return a number for every
    697     * input resulting in {@code true}.</p>
    698     *
    699     * @param str  the {@link String} to check
    700     * @return {@code true} if the string is a correctly formatted number
    701     * @since 3.3 the code supports hexadecimal {@code 0Xhhh} an
    702     *        octal {@code 0ddd} validation
    703     * @deprecated This feature will be removed in Lang 4,
    704     *             use {@link NumberUtils#isCreatable(String)} instead
    705     */
    706    @Deprecated
    707    public static boolean isNumber(final String str) {
    708        return isCreatable(str);
    709    }
    710
    711    /**
    712     * Checks whether the given String is a parsable number.
    713     *
    714     * <p>Parsable numbers include those Strings understood by {@link Integer#parseInt(String)},
    715     * {@link Long#parseLong(String)}, {@link Float#parseFloat(String)} or
    716     * {@link Double#parseDouble(String)}. This method can be used instead of catching {@link java.text.ParseException}
    717     * when calling one of those methods.</p>
    718     *
    719     * <p>Hexadecimal and scientific notations are <strong>not</strong> considered parsable.
    720     * See {@link #isCreatable(String)} on those cases.</p>
    721     *
    722     * <p>{@code null} and empty String will return {@code false}.</p>
    723     *
    724     * @param str the String to check.
    725     * @return {@code true} if the string is a parsable number.
    726     * @since 3.4
    727     */
    728    public static boolean isParsable(final String str) {
    729        if (StringUtils.isEmpty(str)) {
    730            return false;
    731        }
    732        if (str.charAt(str.length() - 1) == '.') {
    733            return false;
    734        }
    735        if (str.charAt(0) == '-') {
    736            if (str.length() == 1) {
    737                return false;
    738            }
    739            return withDecimalsParsing(str, 1);
    740        }
    741        return withDecimalsParsing(str, 0);
    742    }
    743
    744    private static boolean isSign(final char ch) {
    745        return ch == '-' || ch == '+';
    746     }
    747
    748    /**
    749     * Utility method for {@link #createNumber(java.lang.String)}.
    750     *
    751     * <p>This will check if the magnitude of the number is zero by checking if there
    752     * are only zeros before and after the decimal place.</p>
    753     *
    754     * <p>Note: It is <strong>assumed</strong> that the input string has been converted
    755     * to either a Float or Double with a value of zero when this method is called.
    756     * This eliminates invalid input for example {@code ".", ".D", ".e0"}.</p>
    757     *
    758     * <p>Thus the method only requires checking if both arguments are null, empty or
    759     * contain only zeros.</p>
    760     *
    761     * <p>Given {@code s = mant + "." + dec}:</p>
    762     * <ul>
    763     * <li>{@code true} if s is {@code "0.0"}
    764     * <li>{@code true} if s is {@code "0."}
    765     * <li>{@code true} if s is {@code ".0"}
    766     * <li>{@code false} otherwise (this assumes {@code "."} is not possible)
    767     * </ul>
    768     *
    769     * @param mant the mantissa decimal digits before the decimal point (sign must be removed; never null)
    770     * @param dec the decimal digits after the decimal point (exponent and type specifier removed;
    771     *            can be null)
    772     * @return true if the magnitude is zero
    773     */
    774    private static boolean isZero(final String mant, final String dec) {
    775        return isAllZeros(mant) && isAllZeros(dec);
    776    }
    777
    778    /**
    779     * Returns the maximum value in an array.
    780     *
    781     * @param array  an array, must not be null or empty
    782     * @return the maximum value in the array
    783     * @throws NullPointerException if {@code array} is {@code null}
    784     * @throws IllegalArgumentException if {@code array} is empty
    785     * @since 3.4 Changed signature from max(byte[]) to max(byte...)
    786     */
    787    public static byte max(final byte... array) {
    788        // Validates input
    789        validateArray(array);
    790        // Finds and returns max
    791        byte max = array[0];
    792        for (int i = 1; i < array.length; i++) {
    793            if (array[i] > max) {
    794                max = array[i];
    795            }
    796        }
    797        return max;
    798    }
    799
    800    /**
    801     * Gets the maximum of three {@code byte} values.
    802     *
    803     * @param a  value 1
    804     * @param b  value 2
    805     * @param c  value 3
    806     * @return  the largest of the values
    807     */
    808    public static byte max(byte a, final byte b, final byte c) {
    809        if (b > a) {
    810            a = b;
    811        }
    812        if (c > a) {
    813            a = c;
    814        }
    815        return a;
    816    }
    817
    818    /**
    819     * Returns the maximum value in an array.
    820     *
    821     * @param array  an array, must not be null or empty
    822     * @return the maximum value in the array
    823     * @throws NullPointerException if {@code array} is {@code null}
    824     * @throws IllegalArgumentException if {@code array} is empty
    825     * @see IEEE754rUtils#max(double[]) IEEE754rUtils for a version of this method that handles NaN differently
    826     * @since 3.4 Changed signature from max(double[]) to max(double...)
    827     */
    828    public static double max(final double... array) {
    829        // Validates input
    830        validateArray(array);
    831        // Finds and returns max
    832        double max = array[0];
    833        for (int j = 1; j < array.length; j++) {
    834            if (Double.isNaN(array[j])) {
    835                return Double.NaN;
    836            }
    837            if (array[j] > max) {
    838                max = array[j];
    839            }
    840        }
    841        return max;
    842    }
    843
    844    /**
    845     * Gets the maximum of three {@code double} values.
    846     *
    847     * <p>If any value is {@code NaN}, {@code NaN} is
    848     * returned. Infinity is handled.</p>
    849     *
    850     * @param a  value 1
    851     * @param b  value 2
    852     * @param c  value 3
    853     * @return  the largest of the values
    854     * @see IEEE754rUtils#max(double, double, double) for a version of this method that handles NaN differently
    855     */
    856    public static double max(final double a, final double b, final double c) {
    857        return Math.max(Math.max(a, b), c);
    858    }
    859
    860    /**
    861     * Returns the maximum value in an array.
    862     *
    863     * @param array  an array, must not be null or empty
    864     * @return the maximum value in the array
    865     * @throws NullPointerException if {@code array} is {@code null}
    866     * @throws IllegalArgumentException if {@code array} is empty
    867     * @see IEEE754rUtils#max(float[]) IEEE754rUtils for a version of this method that handles NaN differently
    868     * @since 3.4 Changed signature from max(float[]) to max(float...)
    869     */
    870    public static float max(final float... array) {
    871        // Validates input
    872        validateArray(array);
    873        // Finds and returns max
    874        float max = array[0];
    875        for (int j = 1; j < array.length; j++) {
    876            if (Float.isNaN(array[j])) {
    877                return Float.NaN;
    878            }
    879            if (array[j] > max) {
    880                max = array[j];
    881            }
    882        }
    883        return max;
    884    }
    885
    886    // must handle Long, Float, Integer, Float, Short,
    887    //                  BigDecimal, BigInteger and Byte
    888    // useful methods:
    889    // Byte.decode(String)
    890    // Byte.valueOf(String, int radix)
    891    // Byte.valueOf(String)
    892    // Double.valueOf(String)
    893    // Float.valueOf(String)
    894    // Float.valueOf(String)
    895    // Integer.valueOf(String, int radix)
    896    // Integer.valueOf(String)
    897    // Integer.decode(String)
    898    // Integer.getInteger(String)
    899    // Integer.getInteger(String, int val)
    900    // Integer.getInteger(String, Integer val)
    901    // Integer.valueOf(String)
    902    // Double.valueOf(String)
    903    // new Byte(String)
    904    // Long.valueOf(String)
    905    // Long.getLong(String)
    906    // Long.getLong(String, int)
    907    // Long.getLong(String, Integer)
    908    // Long.valueOf(String, int)
    909    // Long.valueOf(String)
    910    // Short.valueOf(String)
    911    // Short.decode(String)
    912    // Short.valueOf(String, int)
    913    // Short.valueOf(String)
    914    // new BigDecimal(String)
    915    // new BigInteger(String)
    916    // new BigInteger(String, int radix)
    917    // Possible inputs:
    918    // 45 45.5 45E7 4.5E7 Hex Oct Binary xxxF xxxD xxxf xxxd
    919    // plus minus everything. Prolly more. A lot are not separable.
    920
    921    /**
    922     * Gets the maximum of three {@code float} values.
    923     *
    924     * <p>If any value is {@code NaN}, {@code NaN} is
    925     * returned. Infinity is handled.</p>
    926     *
    927     * @param a  value 1
    928     * @param b  value 2
    929     * @param c  value 3
    930     * @return  the largest of the values
    931     * @see IEEE754rUtils#max(float, float, float) for a version of this method that handles NaN differently
    932     */
    933    public static float max(final float a, final float b, final float c) {
    934        return Math.max(Math.max(a, b), c);
    935    }
    936
    937    /**
    938     * Returns the maximum value in an array.
    939     *
    940     * @param array  an array, must not be null or empty
    941     * @return the maximum value in the array
    942     * @throws NullPointerException if {@code array} is {@code null}
    943     * @throws IllegalArgumentException if {@code array} is empty
    944     * @since 3.4 Changed signature from max(int[]) to max(int...)
    945     */
    946    public static int max(final int... array) {
    947        // Validates input
    948        validateArray(array);
    949        // Finds and returns max
    950        int max = array[0];
    951        for (int j = 1; j < array.length; j++) {
    952            if (array[j] > max) {
    953                max = array[j];
    954            }
    955        }
    956        return max;
    957    }
    958
    959    /**
    960     * Gets the maximum of three {@code int} values.
    961     *
    962     * @param a  value 1
    963     * @param b  value 2
    964     * @param c  value 3
    965     * @return  the largest of the values
    966     */
    967    public static int max(int a, final int b, final int c) {
    968        if (b > a) {
    969            a = b;
    970        }
    971        if (c > a) {
    972            a = c;
    973        }
    974        return a;
    975    }
    976
    977    /**
    978     * Returns the maximum value in an array.
    979     *
    980     * @param array  an array, must not be null or empty
    981     * @return the maximum value in the array
    982     * @throws NullPointerException if {@code array} is {@code null}
    983     * @throws IllegalArgumentException if {@code array} is empty
    984     * @since 3.4 Changed signature from max(long[]) to max(long...)
    985     */
    986    public static long max(final long... array) {
    987        // Validates input
    988        validateArray(array);
    989        // Finds and returns max
    990        long max = array[0];
    991        for (int j = 1; j < array.length; j++) {
    992            if (array[j] > max) {
    993                max = array[j];
    994            }
    995        }
    996        return max;
    997    }
    998
    999    // 3 param max
    1000    /**
    1001     * Gets the maximum of three {@code long} values.
    1002     *
    1003     * @param a  value 1
    1004     * @param b  value 2
    1005     * @param c  value 3
    1006     * @return  the largest of the values
    1007     */
    1008    public static long max(long a, final long b, final long c) {
    1009        if (b > a) {
    1010            a = b;
    1011        }
    1012        if (c > a) {
    1013            a = c;
    1014        }
    1015        return a;
    1016    }
    1017
    1018    /**
    1019     * Returns the maximum value in an array.
    1020     *
    1021     * @param array  an array, must not be null or empty
    1022     * @return the maximum value in the array
    1023     * @throws NullPointerException if {@code array} is {@code null}
    1024     * @throws IllegalArgumentException if {@code array} is empty
    1025     * @since 3.4 Changed signature from max(short[]) to max(short...)
    1026     */
    1027    public static short max(final short... array) {
    1028        // Validates input
    1029        validateArray(array);
    1030
    1031        // Finds and returns max
    1032        short max = array[0];
    1033        for (int i = 1; i < array.length; i++) {
    1034            if (array[i] > max) {
    1035                max = array[i];
    1036            }
    1037        }
    1038        return max;
    1039    }
    1040
    1041    /**
    1042     * Gets the maximum of three {@code short} values.
    1043     *
    1044     * @param a  value 1
    1045     * @param b  value 2
    1046     * @param c  value 3
    1047     * @return  the largest of the values
    1048     */
    1049    public static short max(short a, final short b, final short c) {
    1050        if (b > a) {
    1051            a = b;
    1052        }
    1053        if (c > a) {
    1054            a = c;
    1055        }
    1056        return a;
    1057    }
    1058
    1059    /**
    1060     * Returns the minimum value in an array.
    1061     *
    1062     * @param array  an array, must not be null or empty
    1063     * @return the minimum value in the array
    1064     * @throws NullPointerException if {@code array} is {@code null}
    1065     * @throws IllegalArgumentException if {@code array} is empty
    1066     * @since 3.4 Changed signature from min(byte[]) to min(byte...)
    1067     */
    1068    public static byte min(final byte... array) {
    1069        // Validates input
    1070        validateArray(array);
    1071        // Finds and returns min
    1072        byte min = array[0];
    1073        for (int i = 1; i < array.length; i++) {
    1074            if (array[i] < min) {
    1075                min = array[i];
    1076            }
    1077        }
    1078        return min;
    1079    }
    1080
    1081    /**
    1082     * Gets the minimum of three {@code byte} values.
    1083     *
    1084     * @param a  value 1
    1085     * @param b  value 2
    1086     * @param c  value 3
    1087     * @return  the smallest of the values
    1088     */
    1089    public static byte min(byte a, final byte b, final byte c) {
    1090        if (b < a) {
    1091            a = b;
    1092        }
    1093        if (c < a) {
    1094            a = c;
    1095        }
    1096        return a;
    1097    }
    1098
    1099    /**
    1100     * Returns the minimum value in an array.
    1101     *
    1102     * @param array  an array, must not be null or empty
    1103     * @return the minimum value in the array
    1104     * @throws NullPointerException if {@code array} is {@code null}
    1105     * @throws IllegalArgumentException if {@code array} is empty
    1106     * @see IEEE754rUtils#min(double[]) IEEE754rUtils for a version of this method that handles NaN differently
    1107     * @since 3.4 Changed signature from min(double[]) to min(double...)
    1108     */
    1109    public static double min(final double... array) {
    1110        // Validates input
    1111        validateArray(array);
    1112
    1113        // Finds and returns min
    1114        double min = array[0];
    1115        for (int i = 1; i < array.length; i++) {
    1116            if (Double.isNaN(array[i])) {
    1117                return Double.NaN;
    1118            }
    1119            if (array[i] < min) {
    1120                min = array[i];
    1121            }
    1122        }
    1123        return min;
    1124    }
    1125
    1126    /**
    1127     * Gets the minimum of three {@code double} values.
    1128     *
    1129     * <p>If any value is {@code NaN}, {@code NaN} is
    1130     * returned. Infinity is handled.</p>
    1131     *
    1132     * @param a  value 1
    1133     * @param b  value 2
    1134     * @param c  value 3
    1135     * @return  the smallest of the values
    1136     * @see IEEE754rUtils#min(double, double, double) for a version of this method that handles NaN differently
    1137     */
    1138    public static double min(final double a, final double b, final double c) {
    1139        return Math.min(Math.min(a, b), c);
    1140    }
    1141
    1142    /**
    1143     * Returns the minimum value in an array.
    1144     *
    1145     * @param array  an array, must not be null or empty
    1146     * @return the minimum value in the array
    1147     * @throws NullPointerException if {@code array} is {@code null}
    1148     * @throws IllegalArgumentException if {@code array} is empty
    1149     * @see IEEE754rUtils#min(float[]) IEEE754rUtils for a version of this method that handles NaN differently
    1150     * @since 3.4 Changed signature from min(float[]) to min(float...)
    1151     */
    1152    public static float min(final float... array) {
    1153        // Validates input
    1154        validateArray(array);
    1155
    1156        // Finds and returns min
    1157        float min = array[0];
    1158        for (int i = 1; i < array.length; i++) {
    1159            if (Float.isNaN(array[i])) {
    1160                return Float.NaN;
    1161            }
    1162            if (array[i] < min) {
    1163                min = array[i];
    1164            }
    1165        }
    1166        return min;
    1167    }
    1168
    1169    /**
    1170     * Gets the minimum of three {@code float} values.
    1171     *
    1172     * <p>If any value is {@code NaN}, {@code NaN} is
    1173     * returned. Infinity is handled.</p>
    1174     *
    1175     * @param a  value 1
    1176     * @param b  value 2
    1177     * @param c  value 3
    1178     * @return  the smallest of the values
    1179     * @see IEEE754rUtils#min(float, float, float) for a version of this method that handles NaN differently
    1180     */
    1181    public static float min(final float a, final float b, final float c) {
    1182        return Math.min(Math.min(a, b), c);
    1183    }
    1184
    1185    /**
    1186     * Returns the minimum value in an array.
    1187     *
    1188     * @param array  an array, must not be null or empty
    1189     * @return the minimum value in the array
    1190     * @throws NullPointerException if {@code array} is {@code null}
    1191     * @throws IllegalArgumentException if {@code array} is empty
    1192     * @since 3.4 Changed signature from min(int[]) to min(int...)
    1193     */
    1194    public static int min(final int... array) {
    1195        // Validates input
    1196        validateArray(array);
    1197        // Finds and returns min
    1198        int min = array[0];
    1199        for (int j = 1; j < array.length; j++) {
    1200            if (array[j] < min) {
    1201                min = array[j];
    1202            }
    1203        }
    1204        return min;
    1205    }
    1206
    1207     /**
    1208     * Gets the minimum of three {@code int} values.
    1209     *
    1210     * @param a  value 1
    1211     * @param b  value 2
    1212     * @param c  value 3
    1213     * @return  the smallest of the values
    1214     */
    1215    public static int min(int a, final int b, final int c) {
    1216        if (b < a) {
    1217            a = b;
    1218        }
    1219        if (c < a) {
    1220            a = c;
    1221        }
    1222        return a;
    1223    }
    1224
    1225    /**
    1226     * Returns the minimum value in an array.
    1227     *
    1228     * @param array  an array, must not be null or empty
    1229     * @return the minimum value in the array
    1230     * @throws NullPointerException if {@code array} is {@code null}
    1231     * @throws IllegalArgumentException if {@code array} is empty
    1232     * @since 3.4 Changed signature from min(long[]) to min(long...)
    1233     */
    1234    public static long min(final long... array) {
    1235        // Validates input
    1236        validateArray(array);
    1237        // Finds and returns min
    1238        long min = array[0];
    1239        for (int i = 1; i < array.length; i++) {
    1240            if (array[i] < min) {
    1241                min = array[i];
    1242            }
    1243        }
    1244        return min;
    1245    }
    1246
    1247    // 3 param min
    1248    /**
    1249     * Gets the minimum of three {@code long} values.
    1250     *
    1251     * @param a  value 1
    1252     * @param b  value 2
    1253     * @param c  value 3
    1254     * @return  the smallest of the values
    1255     */
    1256    public static long min(long a, final long b, final long c) {
    1257        if (b < a) {
    1258            a = b;
    1259        }
    1260        if (c < a) {
    1261            a = c;
    1262        }
    1263        return a;
    1264    }
    1265
    1266    /**
    1267     * Returns the minimum value in an array.
    1268     *
    1269     * @param array  an array, must not be null or empty
    1270     * @return the minimum value in the array
    1271     * @throws NullPointerException if {@code array} is {@code null}
    1272     * @throws IllegalArgumentException if {@code array} is empty
    1273     * @since 3.4 Changed signature from min(short[]) to min(short...)
    1274     */
    1275    public static short min(final short... array) {
    1276        // Validates input
    1277        validateArray(array);
    1278        // Finds and returns min
    1279        short min = array[0];
    1280        for (int i = 1; i < array.length; i++) {
    1281            if (array[i] < min) {
    1282                min = array[i];
    1283            }
    1284        }
    1285
    1286        return min;
    1287    }
    1288
    1289    /**
    1290     * Gets the minimum of three {@code short} values.
    1291     *
    1292     * @param a  value 1
    1293     * @param b  value 2
    1294     * @param c  value 3
    1295     * @return  the smallest of the values
    1296     */
    1297    public static short min(short a, final short b, final short c) {
    1298        if (b < a) {
    1299            a = b;
    1300        }
    1301        if (c < a) {
    1302            a = c;
    1303        }
    1304        return a;
    1305    }
    1306
    1307    /**
    1308     * Converts a {@link String} to a {@code byte}, returning
    1309     * {@code zero} if the conversion fails.
    1310     *
    1311     * <p>If the string is {@code null}, {@code zero} is returned.</p>
    1312     *
    1313     * <pre>
    1314     *   NumberUtils.toByte(null) = 0
    1315     *   NumberUtils.toByte("")   = 0
    1316     *   NumberUtils.toByte("1")  = 1
    1317     * </pre>
    1318     *
    1319     * @param str  the string to convert, may be null
    1320     * @return the byte represented by the string, or {@code zero} if
    1321     *  conversion fails
    1322     * @since 2.5
    1323     */
    1324    public static byte toByte(final String str) {
    1325        return toByte(str, (byte) 0);
    1326    }
    1327
    1328    /**
    1329     * Converts a {@link String} to a {@code byte}, returning a
    1330     * default value if the conversion fails.
    1331     *
    1332     * <p>If the string is {@code null}, the default value is returned.</p>
    1333     *
    1334     * <pre>
    1335     *   NumberUtils.toByte(null, 1) = 1
    1336     *   NumberUtils.toByte("", 1)   = 1
    1337     *   NumberUtils.toByte("1", 0)  = 1
    1338     * </pre>
    1339     *
    1340     * @param str  the string to convert, may be null
    1341     * @param defaultValue  the default value
    1342     * @return the byte represented by the string, or the default if conversion fails
    1343     * @since 2.5
    1344     */
    1345    public static byte toByte(final String str, final byte defaultValue) {
    1346        try {
    1347            return Byte.parseByte(str);
    1348        } catch (final RuntimeException e) {
    1349            return defaultValue;
    1350        }
    1351    }
    1352
    1353    /**
    1354     * Converts a {@link BigDecimal} to a {@code double}.
    1355     *
    1356     * <p>If the {@link BigDecimal} {@code value} is
    1357     * {@code null}, then the specified default value is returned.</p>
    1358     *
    1359     * <pre>
    1360     *   NumberUtils.toDouble(null)                     = 0.0d
    1361     *   NumberUtils.toDouble(BigDecimal.valueOf(8.5d)) = 8.5d
    1362     * </pre>
    1363     *
    1364     * @param value the {@link BigDecimal} to convert, may be {@code null}.
    1365     * @return the double represented by the {@link BigDecimal} or
    1366     *  {@code 0.0d} if the {@link BigDecimal} is {@code null}.
    1367     * @since 3.8
    1368     */
    1369    public static double toDouble(final BigDecimal value) {
    1370        return toDouble(value, 0.0d);
    1371    }
    1372
    1373    /**
    1374     * Converts a {@link BigDecimal} to a {@code double}.
    1375     *
    1376     * <p>If the {@link BigDecimal} {@code value} is
    1377     * {@code null}, then the specified default value is returned.</p>
    1378     *
    1379     * <pre>
    1380     *   NumberUtils.toDouble(null, 1.1d)                     = 1.1d
    1381     *   NumberUtils.toDouble(BigDecimal.valueOf(8.5d), 1.1d) = 8.5d
    1382     * </pre>
    1383     *
    1384     * @param value the {@link BigDecimal} to convert, may be {@code null}.
    1385     * @param defaultValue the default value
    1386     * @return the double represented by the {@link BigDecimal} or the
    1387     *  defaultValue if the {@link BigDecimal} is {@code null}.
    1388     * @since 3.8
    1389     */
    1390    public static double toDouble(final BigDecimal value, final double defaultValue) {
    1391        return value == null ? defaultValue : value.doubleValue();
    1392    }
    1393
    1394    /**
    1395     * Converts a {@link String} to a {@code double}, returning
    1396     * {@code 0.0d} if the conversion fails.
    1397     *
    1398     * <p>If the string {@code str} is {@code null},
    1399     * {@code 0.0d} is returned.</p>
    1400     *
    1401     * <pre>
    1402     *   NumberUtils.toDouble(null)   = 0.0d
    1403     *   NumberUtils.toDouble("")     = 0.0d
    1404     *   NumberUtils.toDouble("1.5")  = 1.5d
    1405     * </pre>
    1406     *
    1407     * @param str the string to convert, may be {@code null}
    1408     * @return the double represented by the string, or {@code 0.0d}
    1409     *  if conversion fails
    1410     * @since 2.1
    1411     */
    1412    public static double toDouble(final String str) {
    1413        return toDouble(str, 0.0d);
    1414    }
    1415
    1416    /**
    1417     * Converts a {@link String} to a {@code double}, returning a
    1418     * default value if the conversion fails.
    1419     *
    1420     * <p>If the string {@code str} is {@code null}, the default
    1421     * value is returned.</p>
    1422     *
    1423     * <pre>
    1424     *   NumberUtils.toDouble(null, 1.1d)   = 1.1d
    1425     *   NumberUtils.toDouble("", 1.1d)     = 1.1d
    1426     *   NumberUtils.toDouble("1.5", 0.0d)  = 1.5d
    1427     * </pre>
    1428     *
    1429     * @param str the string to convert, may be {@code null}
    1430     * @param defaultValue the default value
    1431     * @return the double represented by the string, or defaultValue
    1432     *  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
    1445     * {@code 0.0f} if the conversion fails.
    1446     *
    1447     * <p>If the string {@code str} is {@code null},
    1448     * {@code 0.0f} is returned.</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}
    1458     *  if conversion fails
    1459     * @since 2.1
    1460     */
    1461    public static float toFloat(final String str) {
    1462        return toFloat(str, 0.0f);
    1463    }
    1464
    1465    /**
    1466     * Converts a {@link String} to a {@code float}, returning a
    1467     * default value if the conversion fails.
    1468     *
    1469     * <p>If the string {@code str} is {@code null}, the default
    1470     * value is returned.</p>
    1471     *
    1472     * <pre>
    1473     *   NumberUtils.toFloat(null, 1.1f)   = 1.1f
    1474     *   NumberUtils.toFloat("", 1.1f)     = 1.1f
    1475     *   NumberUtils.toFloat("1.5", 0.0f)  = 1.5f
    1476     * </pre>
    1477     *
    1478     * @param str the string to convert, may be {@code null}
    1479     * @param defaultValue the default value
    1480     * @return the float represented by the string, or defaultValue
    1481     *  if conversion fails
    1482     * @since 2.1
    1483     */
    1484    public static float toFloat(final String str, final float defaultValue) {
    1485      try {
    1486          return Float.parseFloat(str);
    1487      } catch (final RuntimeException e) {
    1488          return defaultValue;
    1489      }
    1490    }
    1491
    1492    /**
    1493     * Converts a {@link String} to an {@code int}, returning
    1494     * {@code zero} if the conversion fails.
    1495     *
    1496     * <p>If the string is {@code null}, {@code zero} is returned.</p>
    1497     *
    1498     * <pre>
    1499     *   NumberUtils.toInt(null) = 0
    1500     *   NumberUtils.toInt("")   = 0
    1501     *   NumberUtils.toInt("1")  = 1
    1502     * </pre>
    1503     *
    1504     * @param str  the string to convert, may be null
    1505     * @return the int represented by the string, or {@code zero} if
    1506     *  conversion fails
    1507     * @since 2.1
    1508     */
    1509    public static int toInt(final String str) {
    1510        return toInt(str, 0);
    1511    }
    1512
    1513    /**
    1514     * Converts a {@link String} to an {@code int}, returning a
    1515     * default value if the conversion fails.
    1516     *
    1517     * <p>If the string is {@code null}, the default value is returned.</p>
    1518     *
    1519     * <pre>
    1520     *   NumberUtils.toInt(null, 1) = 1
    1521     *   NumberUtils.toInt("", 1)   = 1
    1522     *   NumberUtils.toInt("1", 0)  = 1
    1523     * </pre>
    1524     *
    1525     * @param str  the string to convert, may be null
    1526     * @param defaultValue  the default value
    1527     * @return the int represented by the string, or the default if conversion fails
    1528     * @since 2.1
    1529     */
    1530    public static int toInt(final String str, final int defaultValue) {
    1531        try {
    1532            return Integer.parseInt(str);
    1533        } catch (final RuntimeException e) {
    1534            return defaultValue;
    1535        }
    1536    }
    1537
    1538    /**
    1539     * Converts a {@link String} to a {@code long}, returning
    1540     * {@code zero} if the conversion fails.
    1541     *
    1542     * <p>If the string is {@code null}, {@code zero} is returned.</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
    1552     *  conversion fails
    1553     * @since 2.1
    1554     */
    1555    public static long toLong(final String str) {
    1556        return toLong(str, 0L);
    1557    }
    1558
    1559    /**
    1560     * Converts a {@link String} to a {@code long}, returning a
    1561     * default value if the conversion fails.
    1562     *
    1563     * <p>If the string is {@code null}, the default value is returned.</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 conversion 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
    1586     * two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
    1587     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
    1588     *
    1589     * <p>Note, the scale of a {@link BigDecimal} is the number of digits to the right of the
    1590     * decimal point.</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
    1602     * specified value with a {@link RoundingMode} applied. If the input {@code value}
    1603     * is {@code null}, we simply return {@code BigDecimal.ZERO}.
    1604     *
    1605     * @param value the {@link BigDecimal} to convert, may be null.
    1606     * @param scale the number of digits to the right of the decimal point.
    1607     * @param roundingMode a rounding behavior for numerical operations capable of
    1608     *  discarding precision.
    1609     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1610     * @since 3.8
    1611     */
    1612    public static BigDecimal toScaledBigDecimal(final BigDecimal value, final int scale, final RoundingMode roundingMode) {
    1613        if (value == null) {
    1614            return BigDecimal.ZERO;
    1615        }
    1616        return value.setScale(
    1617            scale,
    1618            roundingMode == null ? RoundingMode.HALF_EVEN : roundingMode
    1619        );
    1620    }
    1621
    1622    /**
    1623     * Converts a {@link Double} to a {@link BigDecimal} with a scale of
    1624     * two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
    1625     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
    1626     *
    1627     * <p>Note, the scale of a {@link BigDecimal} is the number of digits to the right of the
    1628     * decimal point.</p>
    1629     *
    1630     * @param value the {@link Double} to convert, may be null.
    1631     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1632     * @since 3.8
    1633     */
    1634    public static BigDecimal toScaledBigDecimal(final Double value) {
    1635        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
    1636    }
    1637
    1638    /**
    1639     * Converts a {@link Double} to a {@link BigDecimal} whose scale is the
    1640     * specified value with a {@link RoundingMode} applied. If the input {@code value}
    1641     * is {@code null}, we simply return {@code BigDecimal.ZERO}.
    1642     *
    1643     * @param value the {@link Double} to convert, may be null.
    1644     * @param scale the number of digits to the right of the decimal point.
    1645     * @param roundingMode a rounding behavior for numerical operations capable of
    1646     *  discarding precision.
    1647     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1648     * @since 3.8
    1649     */
    1650    public static BigDecimal toScaledBigDecimal(final Double value, final int scale, final RoundingMode roundingMode) {
    1651        if (value == null) {
    1652            return BigDecimal.ZERO;
    1653        }
    1654        return toScaledBigDecimal(
    1655            BigDecimal.valueOf(value),
    1656            scale,
    1657            roundingMode
    1658        );
    1659    }
    1660
    1661    /**
    1662     * Converts a {@link Float} to a {@link BigDecimal} with a scale of
    1663     * two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
    1664     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
    1665     *
    1666     * <p>Note, the scale of a {@link BigDecimal} is the number of digits to the right of the
    1667     * decimal point.</p>
    1668     *
    1669     * @param value the {@link Float} to convert, may be null.
    1670     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1671     * @since 3.8
    1672     */
    1673    public static BigDecimal toScaledBigDecimal(final Float value) {
    1674        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
    1675    }
    1676
    1677    /**
    1678     * Converts a {@link Float} to a {@link BigDecimal} whose scale is the
    1679     * specified value with a {@link RoundingMode} applied. If the input {@code value}
    1680     * is {@code null}, we simply return {@code BigDecimal.ZERO}.
    1681     *
    1682     * @param value the {@link Float} to convert, may be null.
    1683     * @param scale the number of digits to the right of the decimal point.
    1684     * @param roundingMode a rounding behavior for numerical operations capable of
    1685     *  discarding precision.
    1686     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1687     * @since 3.8
    1688     */
    1689    public static BigDecimal toScaledBigDecimal(final Float value, final int scale, final RoundingMode roundingMode) {
    1690        if (value == null) {
    1691            return BigDecimal.ZERO;
    1692        }
    1693        return toScaledBigDecimal(
    1694            BigDecimal.valueOf(value),
    1695            scale,
    1696            roundingMode
    1697        );
    1698    }
    1699
    1700    /**
    1701     * Converts a {@link String} to a {@link BigDecimal} with a scale of
    1702     * two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
    1703     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
    1704     *
    1705     * <p>Note, the scale of a {@link BigDecimal} is the number of digits to the right of the
    1706     * decimal point.</p>
    1707     *
    1708     * @param value the {@link String} to convert, may be null.
    1709     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1710     * @since 3.8
    1711     */
    1712    public static BigDecimal toScaledBigDecimal(final String value) {
    1713        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
    1714    }
    1715
    1716    /**
    1717     * Converts a {@link String} to a {@link BigDecimal} whose scale is the
    1718     * specified value with a {@link RoundingMode} applied. If the input {@code value}
    1719     * is {@code null}, we simply return {@code BigDecimal.ZERO}.
    1720     *
    1721     * @param value the {@link String} to convert, may be null.
    1722     * @param scale the number of digits to the right of the decimal point.
    1723     * @param roundingMode a rounding behavior for numerical operations capable of
    1724     *  discarding precision.
    1725     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
    1726     * @since 3.8
    1727     */
    1728    public static BigDecimal toScaledBigDecimal(final String value, final int scale, final RoundingMode roundingMode) {
    1729        if (value == null) {
    1730            return BigDecimal.ZERO;
    1731        }
    1732        return toScaledBigDecimal(
    1733            createBigDecimal(value),
    1734            scale,
    1735            roundingMode
    1736        );
    1737    }
    1738
    1739    /**
    1740     * Converts a {@link String} to a {@code short}, returning
    1741     * {@code zero} if the conversion fails.
    1742     *
    1743     * <p>If the string is {@code null}, {@code zero} is returned.</p>
    1744     *
    1745     * <pre>
    1746     *   NumberUtils.toShort(null) = 0
    1747     *   NumberUtils.toShort("")   = 0
    1748     *   NumberUtils.toShort("1")  = 1
    1749     * </pre>
    1750     *
    1751     * @param str  the string to convert, may be null
    1752     * @return the short represented by the string, or {@code zero} if
    1753     *  conversion fails
    1754     * @since 2.5
    1755     */
    1756    public static short toShort(final String str) {
    1757        return toShort(str, (short) 0);
    1758    }
    1759
    1760    /**
    1761     * Converts a {@link String} to an {@code short}, returning a
    1762     * default value if the conversion fails.
    1763     *
    1764     * <p>If the string is {@code null}, the default value is returned.</p>
    1765     *
    1766     * <pre>
    1767     *   NumberUtils.toShort(null, 1) = 1
    1768     *   NumberUtils.toShort("", 1)   = 1
    1769     *   NumberUtils.toShort("1", 0)  = 1
    1770     * </pre>
    1771     *
    1772     * @param str  the string to convert, may be null
    1773     * @param defaultValue  the default value
    1774     * @return the short represented by the string, or the default if conversion fails
    1775     * @since 2.5
    1776     */
    1777    public static short toShort(final String str, final short defaultValue) {
    1778        try {
    1779            return Short.parseShort(str);
    1780        } catch (final RuntimeException e) {
    1781            return defaultValue;
    1782        }
    1783    }
    1784
    1785    /**
    1786     * Checks if the specified array is neither null nor empty.
    1787     *
    1788     * @param array  the array to check
    1789     * @throws IllegalArgumentException if {@code array} is empty
    1790     * @throws NullPointerException if {@code array} is {@code null}
    1791     */
    1792    private static void validateArray(final Object array) {
    1793        Objects.requireNonNull(array, "array");
    1794        Validate.isTrue(Array.getLength(array) != 0, "Array cannot be empty.");
    1795    }
    1796
    1797    private static boolean withDecimalsParsing(final String str, final int beginIdx) {
    1798        int decimalPoints = 0;
    1799        for (int i = beginIdx; i < str.length(); i++) {
    1800            final char ch = str.charAt(i);
    1801            final boolean isDecimalPoint = ch == '.';
    1802            if (isDecimalPoint) {
    1803                decimalPoints++;
    1804            }
    1805            if (decimalPoints > 1) {
    1806                return false;
    1807            }
    1808            if (!isDecimalPoint && !Character.isDigit(ch)) {
    1809                return false;
    1810            }
    1811        }
    1812        return true;
    1813    }
    1814
    1815    /**
    1816     * {@link NumberUtils} instances should NOT be constructed in standard programming.
    1817     * Instead, the class should be used as {@code NumberUtils.toInt("6");}.
    1818     *
    1819     * <p>This constructor is public to permit tools that require a JavaBean instance
    1820     * to operate.</p>
    1821     *
    1822     * @deprecated TODO Make private in 4.0.
    1823     */
    1824    @Deprecated
    1825    public NumberUtils() {
    1826        // empty
    1827    }
    1828}