Coverage Report

Coverage Report - org.apache.commons.lang3.math.NumberUtils

Classes in this File
Line Coverage
Branch Coverage
Complexity
NumberUtils
98%
363/370
86%
290/337
6.104
 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  * 
  *      http://www.apache.org/licenses/LICENSE-2.0
  * 
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.apache.commons.lang3.math;
 
 import java.lang.reflect.Array;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 
 import org.apache.commons.lang3.StringUtils;
 
 /**
  * <p>Provides extra functionality for Java Number classes.</p>
  *
  * @since 2.0
  * @version $Id: NumberUtils.java 1448286 2013-02-20 16:47:18Z tn $
  */
 public class NumberUtils {
     
     /** Reusable Long constant for zero. */
     public static final Long LONG_ZERO = Long.valueOf(0L);
     /** Reusable Long constant for one. */
     public static final Long LONG_ONE = Long.valueOf(1L);
     /** Reusable Long constant for minus one. */
     public static final Long LONG_MINUS_ONE = Long.valueOf(-1L);
     /** Reusable Integer constant for zero. */
     public static final Integer INTEGER_ZERO = Integer.valueOf(0);
     /** Reusable Integer constant for one. */
     public static final Integer INTEGER_ONE = Integer.valueOf(1);
     /** Reusable Integer constant for minus one. */
     public static final Integer INTEGER_MINUS_ONE = Integer.valueOf(-1);
     /** Reusable Short constant for zero. */
     public static final Short SHORT_ZERO = Short.valueOf((short) 0);
     /** Reusable Short constant for one. */
     public static final Short SHORT_ONE = Short.valueOf((short) 1);
     /** Reusable Short constant for minus one. */
     public static final Short SHORT_MINUS_ONE = Short.valueOf((short) -1);
     /** Reusable Byte constant for zero. */
     public static final Byte BYTE_ZERO = Byte.valueOf((byte) 0);
     /** Reusable Byte constant for one. */
     public static final Byte BYTE_ONE = Byte.valueOf((byte) 1);
     /** Reusable Byte constant for minus one. */
     public static final Byte BYTE_MINUS_ONE = Byte.valueOf((byte) -1);
     /** Reusable Double constant for zero. */
     public static final Double DOUBLE_ZERO = Double.valueOf(0.0d);
     /** Reusable Double constant for one. */
     public static final Double DOUBLE_ONE = Double.valueOf(1.0d);
     /** Reusable Double constant for minus one. */
     public static final Double DOUBLE_MINUS_ONE = Double.valueOf(-1.0d);
     /** Reusable Float constant for zero. */
     public static final Float FLOAT_ZERO = Float.valueOf(0.0f);
     /** Reusable Float constant for one. */
     public static final Float FLOAT_ONE = Float.valueOf(1.0f);
     /** Reusable Float constant for minus one. */
     public static final Float FLOAT_MINUS_ONE = Float.valueOf(-1.0f);
 
     /**
      * <p><code>NumberUtils</code> instances should NOT be constructed in standard programming.
      * Instead, the class should be used as <code>NumberUtils.toInt("6");</code>.</p>
      *
      * <p>This constructor is public to permit tools that require a JavaBean instance
      * to operate.</p>
      */
     public NumberUtils() {
         super();
     }
 
     //-----------------------------------------------------------------------
     /**
      * <p>Convert a <code>String</code> to an <code>int</code>, returning
      * <code>zero</code> if the conversion fails.</p>
      *
      * <p>If the string is <code>null</code>, <code>zero</code> is returned.</p>
      *
      * <pre>
      *   NumberUtils.toInt(null) = 0
      *   NumberUtils.toInt("")   = 0
      *   NumberUtils.toInt("1")  = 1
      * </pre>
      *
      * @param str  the string to convert, may be null
      * @return the int represented by the string, or <code>zero</code> if
      *  conversion fails
      * @since 2.1
      */
     public static int toInt(final String str) {
         return toInt(str, 0);
     }
 
     /**
      * <p>Convert a <code>String</code> to an <code>int</code>, returning a
      * default value if the conversion fails.</p>
      *
      * <p>If the string is <code>null</code>, the default value is returned.</p>
      *
      * <pre>
      *   NumberUtils.toInt(null, 1) = 1
      *   NumberUtils.toInt("", 1)   = 1
      *   NumberUtils.toInt("1", 0)  = 1
      * </pre>
      *
      * @param str  the string to convert, may be null
      * @param defaultValue  the default value
      * @return the int represented by the string, or the default if conversion fails
      * @since 2.1
      */
     public static int toInt(final String str, final int defaultValue) {
         if(str == null) {
             return defaultValue;
         }
         try {
             return Integer.parseInt(str);
         } catch (final NumberFormatException nfe) {
             return defaultValue;
         }
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>long</code>, returning
      * <code>zero</code> if the conversion fails.</p>
      *
      * <p>If the string is <code>null</code>, <code>zero</code> is returned.</p>
      *
      * <pre>
      *   NumberUtils.toLong(null) = 0L
      *   NumberUtils.toLong("")   = 0L
      *   NumberUtils.toLong("1")  = 1L
      * </pre>
      *
      * @param str  the string to convert, may be null
      * @return the long represented by the string, or <code>0</code> if
      *  conversion fails
      * @since 2.1
      */
     public static long toLong(final String str) {
         return toLong(str, 0L);
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>long</code>, returning a
      * default value if the conversion fails.</p>
      *
      * <p>If the string is <code>null</code>, the default value is returned.</p>
      *
      * <pre>
      *   NumberUtils.toLong(null, 1L) = 1L
      *   NumberUtils.toLong("", 1L)   = 1L
      *   NumberUtils.toLong("1", 0L)  = 1L
      * </pre>
      *
      * @param str  the string to convert, may be null
      * @param defaultValue  the default value
      * @return the long represented by the string, or the default if conversion fails
      * @since 2.1
      */
     public static long toLong(final String str, final long defaultValue) {
         if (str == null) {
             return defaultValue;
         }
         try {
             return Long.parseLong(str);
         } catch (final NumberFormatException nfe) {
             return defaultValue;
         }
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>float</code>, returning
      * <code>0.0f</code> if the conversion fails.</p>
      *
      * <p>If the string <code>str</code> is <code>null</code>,
      * <code>0.0f</code> is returned.</p>
      *
      * <pre>
      *   NumberUtils.toFloat(null)   = 0.0f
      *   NumberUtils.toFloat("")     = 0.0f
      *   NumberUtils.toFloat("1.5")  = 1.5f
      * </pre>
      *
      * @param str the string to convert, may be <code>null</code>
      * @return the float represented by the string, or <code>0.0f</code>
      *  if conversion fails
      * @since 2.1
      */
     public static float toFloat(final String str) {
         return toFloat(str, 0.0f);
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>float</code>, returning a
      * default value if the conversion fails.</p>
      *
      * <p>If the string <code>str</code> is <code>null</code>, the default
      * value is returned.</p>
      *
      * <pre>
      *   NumberUtils.toFloat(null, 1.1f)   = 1.0f
      *   NumberUtils.toFloat("", 1.1f)     = 1.1f
      *   NumberUtils.toFloat("1.5", 0.0f)  = 1.5f
      * </pre>
      *
      * @param str the string to convert, may be <code>null</code>
      * @param defaultValue the default value
      * @return the float represented by the string, or defaultValue
      *  if conversion fails
      * @since 2.1
      */
     public static float toFloat(final String str, final float defaultValue) {
       if (str == null) {
           return defaultValue;
       }     
       try {
           return Float.parseFloat(str);
       } catch (final NumberFormatException nfe) {
           return defaultValue;
       }
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>double</code>, returning
      * <code>0.0d</code> if the conversion fails.</p>
      *
      * <p>If the string <code>str</code> is <code>null</code>,
      * <code>0.0d</code> is returned.</p>
      *
      * <pre>
      *   NumberUtils.toDouble(null)   = 0.0d
      *   NumberUtils.toDouble("")     = 0.0d
      *   NumberUtils.toDouble("1.5")  = 1.5d
      * </pre>
      *
      * @param str the string to convert, may be <code>null</code>
      * @return the double represented by the string, or <code>0.0d</code>
      *  if conversion fails
      * @since 2.1
      */
     public static double toDouble(final String str) {
         return toDouble(str, 0.0d);
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>double</code>, returning a
      * default value if the conversion fails.</p>
      *
      * <p>If the string <code>str</code> is <code>null</code>, the default
      * value is returned.</p>
      *
      * <pre>
      *   NumberUtils.toDouble(null, 1.1d)   = 1.1d
      *   NumberUtils.toDouble("", 1.1d)     = 1.1d
      *   NumberUtils.toDouble("1.5", 0.0d)  = 1.5d
      * </pre>
      *
      * @param str the string to convert, may be <code>null</code>
      * @param defaultValue the default value
      * @return the double represented by the string, or defaultValue
      *  if conversion fails
      * @since 2.1
      */
     public static double toDouble(final String str, final double defaultValue) {
       if (str == null) {
           return defaultValue;
       }
       try {
           return Double.parseDouble(str);
       } catch (final NumberFormatException nfe) {
           return defaultValue;
       }
     }
 
      //-----------------------------------------------------------------------
      /**
      * <p>Convert a <code>String</code> to a <code>byte</code>, returning
      * <code>zero</code> if the conversion fails.</p>
      *
      * <p>If the string is <code>null</code>, <code>zero</code> is returned.</p>
      *
      * <pre>
      *   NumberUtils.toByte(null) = 0
      *   NumberUtils.toByte("")   = 0
      *   NumberUtils.toByte("1")  = 1
      * </pre>
      *
      * @param str  the string to convert, may be null
      * @return the byte represented by the string, or <code>zero</code> if
      *  conversion fails
      * @since 2.5
      */
     public static byte toByte(final String str) {
         return toByte(str, (byte) 0);
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>byte</code>, returning a
      * default value if the conversion fails.</p>
      *
      * <p>If the string is <code>null</code>, the default value is returned.</p>
      *
      * <pre>
      *   NumberUtils.toByte(null, 1) = 1
      *   NumberUtils.toByte("", 1)   = 1
      *   NumberUtils.toByte("1", 0)  = 1
      * </pre>
      *
      * @param str  the string to convert, may be null
      * @param defaultValue  the default value
      * @return the byte represented by the string, or the default if conversion fails
      * @since 2.5
      */
     public static byte toByte(final String str, final byte defaultValue) {
         if(str == null) {
             return defaultValue;
         }
         try {
             return Byte.parseByte(str);
         } catch (final NumberFormatException nfe) {
             return defaultValue;
         }
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>short</code>, returning
      * <code>zero</code> if the conversion fails.</p>
      *
      * <p>If the string is <code>null</code>, <code>zero</code> is returned.</p>
      *
      * <pre>
      *   NumberUtils.toShort(null) = 0
      *   NumberUtils.toShort("")   = 0
      *   NumberUtils.toShort("1")  = 1
      * </pre>
      *
      * @param str  the string to convert, may be null
      * @return the short represented by the string, or <code>zero</code> if
      *  conversion fails
      * @since 2.5
      */
     public static short toShort(final String str) {
         return toShort(str, (short) 0);
     }
 
     /**
      * <p>Convert a <code>String</code> to an <code>short</code>, returning a
      * default value if the conversion fails.</p>
      *
      * <p>If the string is <code>null</code>, the default value is returned.</p>
      *
      * <pre>
      *   NumberUtils.toShort(null, 1) = 1
      *   NumberUtils.toShort("", 1)   = 1
      *   NumberUtils.toShort("1", 0)  = 1
      * </pre>
      *
      * @param str  the string to convert, may be null
      * @param defaultValue  the default value
      * @return the short represented by the string, or the default if conversion fails
      * @since 2.5
      */
     public static short toShort(final String str, final short defaultValue) {
         if(str == null) {
             return defaultValue;
         }
         try {
             return Short.parseShort(str);
         } catch (final NumberFormatException nfe) {
             return defaultValue;
         }
     }
 
     //-----------------------------------------------------------------------
     // must handle Long, Float, Integer, Float, Short,
     //                  BigDecimal, BigInteger and Byte
     // useful methods:
     // Byte.decode(String)
     // Byte.valueOf(String,int radix)
     // Byte.valueOf(String)
     // Double.valueOf(String)
     // Float.valueOf(String)
     // Float.valueOf(String)
     // Integer.valueOf(String,int radix)
     // Integer.valueOf(String)
     // Integer.decode(String)
     // Integer.getInteger(String)
     // Integer.getInteger(String,int val)
     // Integer.getInteger(String,Integer val)
     // Integer.valueOf(String)
     // Double.valueOf(String)
     // new Byte(String)
     // Long.valueOf(String)
     // Long.getLong(String)
     // Long.getLong(String,int)
     // Long.getLong(String,Integer)
     // Long.valueOf(String,int)
     // Long.valueOf(String)
     // Short.valueOf(String)
     // Short.decode(String)
     // Short.valueOf(String,int)
     // Short.valueOf(String)
     // new BigDecimal(String)
     // new BigInteger(String)
     // new BigInteger(String,int radix)
     // Possible inputs:
     // 45 45.5 45E7 4.5E7 Hex Oct Binary xxxF xxxD xxxf xxxd
     // plus minus everything. Prolly more. A lot are not separable.
 
     /**
      * <p>Turns a string value into a java.lang.Number.</p>
      *
      * <p>If the string starts with <code>0x</code> or <code>-0x</code> (lower or upper case), it
      * will be interpreted as a hexadecimal integer - or long, if the number of digits after the 0x
      * prefix is more than 8.
      * Values with leading <code>0</code>'s will not be interpreted as octal.</p>
      *
      * <p>Then, the value is examined for a type qualifier on the end, i.e. one of
      * <code>'f','F','d','D','l','L'</code>.  If it is found, it starts 
      * trying to create successively larger types from the type specified
      * until one is found that can represent the value.</p>
      *
      * <p>If a type specifier is not found, it will check for a decimal point
      * and then try successively larger types from <code>Integer</code> to
      * <code>BigInteger</code> and from <code>Float</code> to
      * <code>BigDecimal</code>.</p>
      *
      * <p>Returns <code>null</code> if the string is <code>null</code>.</p>
      *
      * <p>This method does not trim the input string, i.e., strings with leading
      * or trailing spaces will generate NumberFormatExceptions.</p>
      *
      * @param str  String containing a number, may be null
      * @return Number created from the string (or null if the input is null)
      * @throws NumberFormatException if the value cannot be converted
      */
     public static Number createNumber(final String str) throws NumberFormatException {
         if (str == null) {
             return null;
         }
         if (StringUtils.isBlank(str)) {
             throw new NumberFormatException("A blank string is not a valid number");
         }
         // Need to deal with all possible hex prefixes here
         final String[] hex_prefixes = {"0x", "0X", "-0x", "-0X", "#", "-#"};
         int pfxLen = 0;
         for(final String pfx : hex_prefixes) {
             if (str.startsWith(pfx)) {
                 pfxLen += pfx.length();
                 break;
             }
         }
         if (pfxLen > 0) {
             final int hexDigits = str.length() - pfxLen;
             if (hexDigits > 16) { // too many for Long
                 return createBigInteger(str);
             }
             if (hexDigits > 8) { // too many for an int
                 return createLong(str);
             }
             return createInteger(str);
         }
         final char lastChar = str.charAt(str.length() - 1);
         String mant;
         String dec;
         String exp;
         final int decPos = str.indexOf('.');
         final int expPos = str.indexOf('e') + str.indexOf('E') + 1;
 
         if (decPos > -1) {
 
             if (expPos > -1) {
                 if (expPos < decPos || expPos > str.length()) {
                     throw new NumberFormatException(str + " is not a valid number.");
                 }
                 dec = str.substring(decPos + 1, expPos);
             } else {
                 dec = str.substring(decPos + 1);
             }
             mant = str.substring(0, decPos);
         } else {
             if (expPos > -1) {
                 if (expPos > str.length()) {
                     throw new NumberFormatException(str + " is not a valid number.");
                 }
                 mant = str.substring(0, expPos);
             } else {
                 mant = str;
             }
             dec = null;
         }
         if (!Character.isDigit(lastChar) && lastChar != '.') {
             if (expPos > -1 && expPos < str.length() - 1) {
                 exp = str.substring(expPos + 1, str.length() - 1);
             } else {
                 exp = null;
             }
             //Requesting a specific type..
             final String numeric = str.substring(0, str.length() - 1);
             final boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
             switch (lastChar) {
                 case 'l' :
                 case 'L' :
                     if (dec == null
                         && exp == null
                         && (numeric.charAt(0) == '-' && isDigits(numeric.substring(1)) || isDigits(numeric))) {
                         try {
                             return createLong(numeric);
                         } catch (final NumberFormatException nfe) { // NOPMD
                             // Too big for a long
                         }
                         return createBigInteger(numeric);
 
                     }
                     throw new NumberFormatException(str + " is not a valid number.");
                 case 'f' :
                 case 'F' :
                     try {
                         final Float f = NumberUtils.createFloat(numeric);
                         if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) {
                             //If it's too big for a float or the float value = 0 and the string
                             //has non-zeros in it, then float does not have the precision we want
                             return f;
                         }
 
                     } catch (final NumberFormatException nfe) { // NOPMD
                         // ignore the bad number
                     }
                     //$FALL-THROUGH$
                 case 'd' :
                 case 'D' :
                     try {
                         final Double d = NumberUtils.createDouble(numeric);
                         if (!(d.isInfinite() || (d.floatValue() == 0.0D && !allZeros))) {
                             return d;
                         }
                     } catch (final NumberFormatException nfe) { // NOPMD
                         // ignore the bad number
                     }
                     try {
                         return createBigDecimal(numeric);
                     } catch (final NumberFormatException e) { // NOPMD
                         // ignore the bad number
                     }
                     //$FALL-THROUGH$
                 default :
                     throw new NumberFormatException(str + " is not a valid number.");
 
             }
         } else {
             //User doesn't have a preference on the return type, so let's start
             //small and go from there...
             if (expPos > -1 && expPos < str.length() - 1) {
                 exp = str.substring(expPos + 1, str.length());
             } else {
                 exp = null;
             }
             if (dec == null && exp == null) {
                 //Must be an int,long,bigint
                 try {
                     return createInteger(str);
                 } catch (final NumberFormatException nfe) { // NOPMD
                     // ignore the bad number
                 }
                 try {
                     return createLong(str);
                 } catch (final NumberFormatException nfe) { // NOPMD
                     // ignore the bad number
                 }
                 return createBigInteger(str);
 
             } else {
                 //Must be a float,double,BigDec
                 final boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
                 try {
                     final Float f = createFloat(str);
                     if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) {
                         return f;
                     }
                 } catch (final NumberFormatException nfe) { // NOPMD
                     // ignore the bad number
                 }
                 try {
                     final Double d = createDouble(str);
                     if (!(d.isInfinite() || (d.doubleValue() == 0.0D && !allZeros))) {
                         return d;
                     }
                 } catch (final NumberFormatException nfe) { // NOPMD
                     // ignore the bad number
                 }
 
                 return createBigDecimal(str);
 
             }
         }
     }
 
     /**
      * <p>Utility method for {@link #createNumber(java.lang.String)}.</p>
      *
      * <p>Returns <code>true</code> if s is <code>null</code>.</p>
      * 
      * @param str  the String to check
      * @return if it is all zeros or <code>null</code>
      */
     private static boolean isAllZeros(final String str) {
         if (str == null) {
             return true;
         }
         for (int i = str.length() - 1; i >= 0; i--) {
             if (str.charAt(i) != '0') {
                 return false;
             }
         }
         return str.length() > 0;
     }
 
     //-----------------------------------------------------------------------
     /**
      * <p>Convert a <code>String</code> to a <code>Float</code>.</p>
      *
      * <p>Returns <code>null</code> if the string is <code>null</code>.</p>
      * 
      * @param str  a <code>String</code> to convert, may be null
      * @return converted <code>Float</code> (or null if the input is null)
      * @throws NumberFormatException if the value cannot be converted
      */
     public static Float createFloat(final String str) {
         if (str == null) {
             return null;
         }
         return Float.valueOf(str);
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>Double</code>.</p>
      * 
      * <p>Returns <code>null</code> if the string is <code>null</code>.</p>
      *
      * @param str  a <code>String</code> to convert, may be null
      * @return converted <code>Double</code> (or null if the input is null)
      * @throws NumberFormatException if the value cannot be converted
      */
     public static Double createDouble(final String str) {
         if (str == null) {
             return null;
         }
         return Double.valueOf(str);
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>Integer</code>, handling
      * hex and octal notations.</p>
      *
      * <p>Returns <code>null</code> if the string is <code>null</code>.</p>
      * 
      * @param str  a <code>String</code> to convert, may be null
      * @return converted <code>Integer</code> (or null if the input is null)
      * @throws NumberFormatException if the value cannot be converted
      */
     public static Integer createInteger(final String str) {
         if (str == null) {
             return null;
         }
         // decode() handles 0xAABD and 0777 (hex and octal) as well.
         return Integer.decode(str);
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>Long</code>; 
      * since 3.1 it handles hex and octal notations.</p>
      * 
      * <p>Returns <code>null</code> if the string is <code>null</code>.</p>
      *
      * @param str  a <code>String</code> to convert, may be null
      * @return converted <code>Long</code> (or null if the input is null)
      * @throws NumberFormatException if the value cannot be converted
      */
     public static Long createLong(final String str) {
         if (str == null) {
             return null;
         }
         return Long.decode(str);
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>BigInteger</code>;
      * since 3.2 it handles hex (0x or #) and octal (0) notations.</p>
      *
      * <p>Returns <code>null</code> if the string is <code>null</code>.</p>
      * 
      * @param str  a <code>String</code> to convert, may be null
      * @return converted <code>BigInteger</code> (or null if the input is null)
      * @throws NumberFormatException if the value cannot be converted
      */
     public static BigInteger createBigInteger(final String str) {
         if (str == null) {
             return null;
         }
         int pos = 0; // offset within string
         int radix = 10;
         boolean negate = false; // need to negate later?
         if (str.startsWith("-")) {
             negate = true;
             pos = 1;
         }
         if (str.startsWith("0x", pos) || str.startsWith("0x", pos)) { // hex
             radix = 16;
             pos += 2;
         } else if (str.startsWith("#", pos)) { // alternative hex (allowed by Long/Integer)
             radix = 16;
             pos ++;
         } else if (str.startsWith("0", pos) && str.length() > pos + 1) { // octal; so long as there are additional digits
             radix = 8;
             pos ++;
         } // default is to treat as decimal
 
         final BigInteger value = new BigInteger(str.substring(pos), radix);
         return negate ? value.negate() : value;
     }
 
     /**
      * <p>Convert a <code>String</code> to a <code>BigDecimal</code>.</p>
      * 
      * <p>Returns <code>null</code> if the string is <code>null</code>.</p>
      *
      * @param str  a <code>String</code> to convert, may be null
      * @return converted <code>BigDecimal</code> (or null if the input is null)
      * @throws NumberFormatException if the value cannot be converted
      */
     public static BigDecimal createBigDecimal(final String str) {
         if (str == null) {
             return null;
         }
         // handle JDK1.3.1 bug where "" throws IndexOutOfBoundsException
         if (StringUtils.isBlank(str)) {
             throw new NumberFormatException("A blank string is not a valid number");
         }
         if (str.trim().startsWith("--")) {
             // this is protection for poorness in java.lang.BigDecimal.
             // it accepts this as a legal value, but it does not appear 
             // to be in specification of class. OS X Java parses it to 
             // a wrong value.
             throw new NumberFormatException(str + " is not a valid number.");
         }
         return new BigDecimal(str);
     }
 
     // Min in array
     //--------------------------------------------------------------------
     /**
      * <p>Returns the minimum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      */
     public static long min(final long[] array) {
         // Validates input
         validateArray(array);
     
         // Finds and returns min
         long min = array[0];
         for (int i = 1; i < array.length; i++) {
             if (array[i] < min) {
                 min = array[i];
             }
         }
     
         return min;
     }
 
     /**
      * <p>Returns the minimum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      */
     public static int min(final int[] array) {
         // Validates input
         validateArray(array);
     
         // Finds and returns min
         int min = array[0];
         for (int j = 1; j < array.length; j++) {
             if (array[j] < min) {
                 min = array[j];
             }
         }
     
         return min;
     }
 
     /**
      * <p>Returns the minimum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      */
     public static short min(final short[] array) {
         // Validates input
         validateArray(array);
     
         // Finds and returns min
         short min = array[0];
         for (int i = 1; i < array.length; i++) {
             if (array[i] < min) {
                 min = array[i];
             }
         }
     
         return min;
     }
 
     /**
      * <p>Returns the minimum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      */
     public static byte min(final byte[] array) {
         // Validates input
         validateArray(array);
     
         // Finds and returns min
         byte min = array[0];
         for (int i = 1; i < array.length; i++) {
             if (array[i] < min) {
                 min = array[i];
             }
         }
     
         return min;
     }
 
      /**
      * <p>Returns the minimum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      * @see IEEE754rUtils#min(double[]) IEEE754rUtils for a version of this method that handles NaN differently
      */
     public static double min(final double[] array) {
         // Validates input
         validateArray(array);
     
         // Finds and returns min
         double min = array[0];
         for (int i = 1; i < array.length; i++) {
             if (Double.isNaN(array[i])) {
                 return Double.NaN;
             }
             if (array[i] < min) {
                 min = array[i];
             }
         }
     
         return min;
     }
 
     /**
      * <p>Returns the minimum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      * @see IEEE754rUtils#min(float[]) IEEE754rUtils for a version of this method that handles NaN differently
      */
     public static float min(final float[] array) {
         // Validates input
         validateArray(array);
     
         // Finds and returns min
         float min = array[0];
         for (int i = 1; i < array.length; i++) {
             if (Float.isNaN(array[i])) {
                 return Float.NaN;
             }
             if (array[i] < min) {
                 min = array[i];
             }
         }
     
         return min;
     }
 
     // Max in array
     //--------------------------------------------------------------------
     /**
      * <p>Returns the maximum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      */
     public static long max(final long[] array) {
         // Validates input
         validateArray(array);
 
         // Finds and returns max
         long max = array[0];
         for (int j = 1; j < array.length; j++) {
             if (array[j] > max) {
                 max = array[j];
             }
         }
 
         return max;
     }
 
     /**
      * <p>Returns the maximum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      */
     public static int max(final int[] array) {
         // Validates input
         validateArray(array);
     
         // Finds and returns max
         int max = array[0];
         for (int j = 1; j < array.length; j++) {
             if (array[j] > max) {
                 max = array[j];
             }
         }
     
         return max;
     }
 
     /**
      * <p>Returns the maximum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      */
     public static short max(final short[] array) {
         // Validates input
         validateArray(array);
     
         // Finds and returns max
         short max = array[0];
         for (int i = 1; i < array.length; i++) {
             if (array[i] > max) {
                 max = array[i];
             }
         }
     
         return max;
     }
 
     /**
      * <p>Returns the maximum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      */
     public static byte max(final byte[] array) {
         // Validates input
         validateArray(array);
     
         // Finds and returns max
         byte max = array[0];
         for (int i = 1; i < array.length; i++) {
             if (array[i] > max) {
                 max = array[i];
             }
         }
     
         return max;
     }
 
     /**
      * <p>Returns the maximum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      * @see IEEE754rUtils#max(double[]) IEEE754rUtils for a version of this method that handles NaN differently
      */
     public static double max(final double[] array) {
         // Validates input
         validateArray(array);
 
         // Finds and returns max
         double max = array[0];
         for (int j = 1; j < array.length; j++) {
             if (Double.isNaN(array[j])) {
                 return Double.NaN;
             }
             if (array[j] > max) {
                 max = array[j];
             }
         }
     
         return max;
     }
 
     /**
      * <p>Returns the maximum value in an array.</p>
      * 
      * @param array  an array, must not be null or empty
      * @return the minimum value in the array
      * @throws IllegalArgumentException if <code>array</code> is <code>null</code>
      * @throws IllegalArgumentException if <code>array</code> is empty
      * @see IEEE754rUtils#max(float[]) IEEE754rUtils for a version of this method that handles NaN differently
      */
     public static float max(final float[] array) {
         // Validates input
         validateArray(array);
 
         // Finds and returns max
         float max = array[0];
         for (int j = 1; j < array.length; j++) {
             if (Float.isNaN(array[j])) {
                 return Float.NaN;
             }
             if (array[j] > max) {
                 max = array[j];
             }
         }
 
         return max;
     }
 
     /**
      * Checks if the specified array is neither null nor empty.
      *
      * @param array  the array to check
      * @throws IllegalArgumentException if {@code array} is either {@code null} or empty
      */
     private static void validateArray(final Object array) {
         if (array == null) {
             throw new IllegalArgumentException("The Array must not be null");
         } else if (Array.getLength(array) == 0) {
             throw new IllegalArgumentException("Array cannot be empty.");
         }
     }
      
     // 3 param min
     //-----------------------------------------------------------------------
     /**
      * <p>Gets the minimum of three <code>long</code> values.</p>
      * 
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the smallest of the values
      */
     public static long min(long a, final long b, final long c) {
         if (b < a) {
             a = b;
         }
         if (c < a) {
             a = c;
         }
         return a;
     }
 
     /**
      * <p>Gets the minimum of three <code>int</code> values.</p>
      * 
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the smallest of the values
      */
     public static int min(int a, final int b, final int c) {
         if (b < a) {
             a = b;
         }
         if (c < a) {
             a = c;
         }
         return a;
     }
 
     /**
      * <p>Gets the minimum of three <code>short</code> values.</p>
      * 
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the smallest of the values
      */
     public static short min(short a, final short b, final short c) {
         if (b < a) {
             a = b;
         }
         if (c < a) {
             a = c;
         }
         return a;
     }
 
     /**
      * <p>Gets the minimum of three <code>byte</code> values.</p>
      * 
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the smallest of the values
      */
     public static byte min(byte a, final byte b, final byte c) {
         if (b < a) {
             a = b;
         }
         if (c < a) {
             a = c;
         }
         return a;
     }
 
     /**
      * <p>Gets the minimum of three <code>double</code> values.</p>
      * 
      * <p>If any value is <code>NaN</code>, <code>NaN</code> is
      * returned. Infinity is handled.</p>
      * 
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the smallest of the values
      * @see IEEE754rUtils#min(double, double, double) for a version of this method that handles NaN differently
      */
     public static double min(final double a, final double b, final double c) {
         return Math.min(Math.min(a, b), c);
     }
 
     /**
      * <p>Gets the minimum of three <code>float</code> values.</p>
      * 
      * <p>If any value is <code>NaN</code>, <code>NaN</code> is
      * returned. Infinity is handled.</p>
      *
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the smallest of the values
      * @see IEEE754rUtils#min(float, float, float) for a version of this method that handles NaN differently
      */
     public static float min(final float a, final float b, final float c) {
         return Math.min(Math.min(a, b), c);
     }
 
     // 3 param max
     //-----------------------------------------------------------------------
     /**
      * <p>Gets the maximum of three <code>long</code> values.</p>
      * 
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the largest of the values
      */
     public static long max(long a, final long b, final long c) {
         if (b > a) {
             a = b;
         }
         if (c > a) {
             a = c;
         }
         return a;
     }
 
     /**
      * <p>Gets the maximum of three <code>int</code> values.</p>
      * 
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the largest of the values
      */
     public static int max(int a, final int b, final int c) {
         if (b > a) {
             a = b;
         }
         if (c > a) {
             a = c;
         }
         return a;
     }
 
     /**
      * <p>Gets the maximum of three <code>short</code> values.</p>
      * 
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the largest of the values
      */
     public static short max(short a, final short b, final short c) {
         if (b > a) {
             a = b;
         }
         if (c > a) {
             a = c;
         }
         return a;
     }
 
     /**
      * <p>Gets the maximum of three <code>byte</code> values.</p>
      * 
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the largest of the values
      */
     public static byte max(byte a, final byte b, final byte c) {
         if (b > a) {
             a = b;
         }
         if (c > a) {
             a = c;
         }
         return a;
     }
 
     /**
      * <p>Gets the maximum of three <code>double</code> values.</p>
      * 
      * <p>If any value is <code>NaN</code>, <code>NaN</code> is
      * returned. Infinity is handled.</p>
      *
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the largest of the values
      * @see IEEE754rUtils#max(double, double, double) for a version of this method that handles NaN differently
      */
     public static double max(final double a, final double b, final double c) {
         return Math.max(Math.max(a, b), c);
     }
 
     /**
      * <p>Gets the maximum of three <code>float</code> values.</p>
      * 
      * <p>If any value is <code>NaN</code>, <code>NaN</code> is
      * returned. Infinity is handled.</p>
      *
      * @param a  value 1
      * @param b  value 2
      * @param c  value 3
      * @return  the largest of the values
      * @see IEEE754rUtils#max(float, float, float) for a version of this method that handles NaN differently
      */
     public static float max(final float a, final float b, final float c) {
         return Math.max(Math.max(a, b), c);
     }
 
     //-----------------------------------------------------------------------
     /**
      * <p>Checks whether the <code>String</code> contains only
      * digit characters.</p>
      *
      * <p><code>Null</code> and empty String will return
      * <code>false</code>.</p>
      *
      * @param str  the <code>String</code> to check
      * @return <code>true</code> if str contains only Unicode numeric
      */
     public static boolean isDigits(final String str) {
         if (StringUtils.isEmpty(str)) {
             return false;
         }
         for (int i = 0; i < str.length(); i++) {
             if (!Character.isDigit(str.charAt(i))) {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * <p>Checks whether the String a valid Java number.</p>
      *
      * <p>Valid numbers include hexadecimal marked with the <code>0x</code>
      * qualifier, scientific notation and numbers marked with a type
      * qualifier (e.g. 123L).</p>
      *
      * <p><code>Null</code> and empty String will return
      * <code>false</code>.</p>
      *
      * @param str  the <code>String</code> to check
      * @return <code>true</code> if the string is a correctly formatted number
      */
     public static boolean isNumber(final String str) {
         if (StringUtils.isEmpty(str)) {
             return false;
         }
         final char[] chars = str.toCharArray();
         int sz = chars.length;
         boolean hasExp = false;
         boolean hasDecPoint = false;
         boolean allowSigns = false;
         boolean foundDigit = false;
         // deal with any possible sign up front
         final int start = (chars[0] == '-') ? 1 : 0;
         if (sz > start + 1 && chars[start] == '0' && chars[start + 1] == 'x') {
             int i = start + 2;
             if (i == sz) {
                 return false; // str == "0x"
             }
             // checking hex (it can't be anything else)
             for (; i < chars.length; i++) {
                 if ((chars[i] < '0' || chars[i] > '9')
                     && (chars[i] < 'a' || chars[i] > 'f')
                     && (chars[i] < 'A' || chars[i] > 'F')) {
                     return false;
                 }
             }
             return true;
         }
         sz--; // don't want to loop to the last char, check it afterwords
               // for type qualifiers
         int i = start;
         // loop to the next to last char or to the last char if we need another digit to
         // make a valid number (e.g. chars[0..5] = "1234E")
         while (i < sz || (i < sz + 1 && allowSigns && !foundDigit)) {
             if (chars[i] >= '0' && chars[i] <= '9') {
                 foundDigit = true;
                 allowSigns = false;
 
             } else if (chars[i] == '.') {
                 if (hasDecPoint || hasExp) {
                     // two decimal points or dec in exponent   
                     return false;
                 }
                 hasDecPoint = true;
             } else if (chars[i] == 'e' || chars[i] == 'E') {
                 // we've already taken care of hex.
                 if (hasExp) {
                     // two E's
                     return false;
                 }
                 if (!foundDigit) {
                     return false;
                 }
                 hasExp = true;
                 allowSigns = true;
             } else if (chars[i] == '+' || chars[i] == '-') {
                 if (!allowSigns) {
                     return false;
                 }
                 allowSigns = false;
                 foundDigit = false; // we need a digit after the E
             } else {
                 return false;
             }
             i++;
         }
         if (i < chars.length) {
             if (chars[i] >= '0' && chars[i] <= '9') {
                 // no type qualifier, OK
                 return true;
             }
             if (chars[i] == 'e' || chars[i] == 'E') {
                 // can't have an E at the last byte
                 return false;
             }
             if (chars[i] == '.') {
                 if (hasDecPoint || hasExp) {
                     // two decimal points or dec in exponent
                     return false;
                 }
                 // single trailing decimal point after non-exponent is ok
                 return foundDigit;
             }
             if (!allowSigns
                 && (chars[i] == 'd'
                     || chars[i] == 'D'
                     || chars[i] == 'f'
                     || chars[i] == 'F')) {
                 return foundDigit;
             }
             if (chars[i] == 'l'
                 || chars[i] == 'L') {
                 // not allowing L with an exponent or decimal point
                 return foundDigit && !hasExp && !hasDecPoint;
             }
             // last character is illegal
             return false;
         }
         // allowSigns is true iff the val ends in 'E'
         // found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
         return !allowSigns && foundDigit;
     }
 
 }