code: /*
   * 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.lang;
  
  import java.math.BigDecimal;
  import java.math.BigInteger;
  
  /**
   * <p>Provides extra functionality for Java Number classes.</p>
   *
   * @author <a href="mailto:rand_mcneely@yahoo.com">Rand McNeely</a>
   * @author Stephen Colebourne
   * @author <a href="mailto:steve.downey@netfolio.com">Steve Downey</a>
   * @author Eric Pugh
   * @author Phil Steitz
   * @since 1.0
   * @version $Id: NumberUtils.java 488819 2006-12-19 21:50:04Z bayard $
   * 
   * @deprecated Moved to org.apache.commons.lang.math.
   *             Class will be removed in Commons Lang 3.0.
   */
  public final class NumberUtils {
      // DEPRECATED CLASS !!!
      
      /**
       * <p><code>NumberUtils</code> instances should NOT be constructed in standard programming.
       * Instead, the class should be used as <code>NumberUtils.stringToInt("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>
       * 
       * @param str  the string to convert
       * @return the int represented by the string, or <code>zero</code> if
       *  conversion fails
       */
      public static int stringToInt(String str) {
          return stringToInt(str, 0);
      }
  
      /**
       * <p>Convert a <code>String</code> to an <code>int</code>, returning a
       * default value if the conversion fails.</p>
       * 
       * @param str  the string to convert
       * @param defaultValue  the default value
       * @return the int represented by the string, or the default if conversion fails
       */
      public static int stringToInt(String str, int defaultValue) {
          try {
              return Integer.parseInt(str);
          } catch (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)
      // new Float(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)
      // new Integer(String)
      // new Double(String)
      // new Byte(String)
      // new Long(String)
      // Long.getLong(String)
      // Long.getLong(String,int)
      // Long.getLong(String,Integer)
      // Long.valueOf(String,int)
      // Long.valueOf(String)
      // new Short(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>First, the value is examined for a type qualifier on the end
       * (<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 hold 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>If the string starts with <code>0x</code> or <code>-0x</code>, it
       * will be interpreted as a hexadecimal integer.  Values with leading
       * <code>0</code>'s will not be interpreted as octal.</p>
       *
       * @param val String containing a number
       * @return Number created from the string
       * @throws NumberFormatException if the value cannot be converted
       */
      public static Number createNumber(String val) throws NumberFormatException {
          if (val == null) {
              return null;
          }
          if (val.length() == 0) {
              throw new NumberFormatException("\"\" is not a valid number.");
          }
          if (val.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.
              return null;
          }
          if (val.startsWith("0x") || val.startsWith("-0x")) {
              return createInteger(val);
          }   
          char lastChar = val.charAt(val.length() - 1);
          String mant;
          String dec;
          String exp;
          int decPos = val.indexOf('.');
          int expPos = val.indexOf('e') + val.indexOf('E') + 1;
  
          if (decPos > -1) {
  
              if (expPos > -1) {
                  if (expPos < decPos) {
                      throw new NumberFormatException(val + " is not a valid number.");
                  }
                  dec = val.substring(decPos + 1, expPos);
              } else {
                  dec = val.substring(decPos + 1);
              }
              mant = val.substring(0, decPos);
          } else {
              if (expPos > -1) {
                  mant = val.substring(0, expPos);
              } else {
                  mant = val;
              }
              dec = null;
          }
          if (!Character.isDigit(lastChar)) {
              if (expPos > -1 && expPos < val.length() - 1) {
                  exp = val.substring(expPos + 1, val.length() - 1);
              } else {
                  exp = null;
              }
              //Requesting a specific type..
              String numeric = val.substring(0, val.length() - 1);
              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 (NumberFormatException nfe) {
                              //Too big for a long
                          }
                          return createBigInteger(numeric);
  
                      }
                      throw new NumberFormatException(val + " is not a valid number.");
                  case 'f' :
                  case 'F' :
                      try {
                          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 (NumberFormatException e) {
                          // ignore the bad number
                      }
                      //Fall through
                  case 'd' :
                  case 'D' :
                      try {
                          Double d = NumberUtils.createDouble(numeric);
                          if (!(d.isInfinite() || (d.floatValue() == 0.0D && !allZeros))) {
                              return d;
                          }
                      } catch (NumberFormatException nfe) {
                          // empty catch
                      }
                      try {
                          return createBigDecimal(numeric);
                      } catch (NumberFormatException e) {
                          // empty catch
                      }
                      //Fall through
                  default :
                      throw new NumberFormatException(val + " 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 < val.length() - 1) {
                  exp = val.substring(expPos + 1, val.length());
              } else {
                  exp = null;
              }
              if (dec == null && exp == null) {
                  //Must be an int,long,bigint
                  try {
                      return createInteger(val);
                  } catch (NumberFormatException nfe) {
                      // empty catch
                  }
                  try {
                      return createLong(val);
                  } catch (NumberFormatException nfe) {
                      // empty catch
                  }
                  return createBigInteger(val);
  
              } else {
                  //Must be a float,double,BigDec
                  boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
                  try {
                      Float f = createFloat(val);
                      if (!(f.isInfinite() || (f.floatValue() == 0.0F && !allZeros))) {
                          return f;
                      }
                  } catch (NumberFormatException nfe) {
                      // empty catch
                  }
                  try {
                      Double d = createDouble(val);
                      if (!(d.isInfinite() || (d.doubleValue() == 0.0D && !allZeros))) {
                          return d;
                      }
                  } catch (NumberFormatException nfe) {
                      // empty catch
                  }
  
                  return createBigDecimal(val);
  
              }
  
          }
      }
  
      /**
       * <p>Utility method for {@link #createNumber(java.lang.String)}.</p>
       *
       * <p>Returns <code>true</code> if s is <code>null</code>.</p>
       * 
       * @param s the String to check
       * @return if it is all zeros or <code>null</code>
       */
      private static boolean isAllZeros(String s) {
          if (s == null) {
              return true;
          }
          for (int i = s.length() - 1; i >= 0; i--) {
              if (s.charAt(i) != '0') {
                  return false;
              }
          }
          return s.length() > 0;
      }
  
      //--------------------------------------------------------------------
      
      /**
       * <p>Convert a <code>String</code> to a <code>Float</code>.</p>
       * 
       * @param val  a <code>String</code> to convert
       * @return converted <code>Float</code>
       * @throws NumberFormatException if the value cannot be converted
       */
      public static Float createFloat(String val) {
          return Float.valueOf(val);
      }
  
      /**
       * <p>Convert a <code>String</code> to a <code>Double</code>.</p>
       * 
       * @param val  a <code>String</code> to convert
       * @return converted <code>Double</code>
       * @throws NumberFormatException if the value cannot be converted
       */
      public static Double createDouble(String val) {
          return Double.valueOf(val);
      }
  
      /**
       * <p>Convert a <code>String</code> to a <code>Integer</code>, handling
       * hex and octal notations.</p>
       * 
       * @param val  a <code>String</code> to convert
       * @return converted <code>Integer</code>
       * @throws NumberFormatException if the value cannot be converted
       */
      public static Integer createInteger(String val) {
          // decode() handles 0xAABD and 0777 (hex and octal) as well.
          return Integer.decode(val);
      }
  
      /**
       * <p>Convert a <code>String</code> to a <code>Long</code>.</p>
       * 
       * @param val  a <code>String</code> to convert
       * @return converted <code>Long</code>
       * @throws NumberFormatException if the value cannot be converted
       */
      public static Long createLong(String val) {
          return Long.valueOf(val);
      }
  
      /**
       * <p>Convert a <code>String</code> to a <code>BigInteger</code>.</p>
       * 
       * @param val  a <code>String</code> to convert
       * @return converted <code>BigInteger</code>
       * @throws NumberFormatException if the value cannot be converted
       */
      public static BigInteger createBigInteger(String val) {
          BigInteger bi = new BigInteger(val);
          return bi;
      }
  
      /**
       * <p>Convert a <code>String</code> to a <code>BigDecimal</code>.</p>
       * 
       * @param val  a <code>String</code> to convert
       * @return converted <code>BigDecimal</code>
       * @throws NumberFormatException if the value cannot be converted
       */
      public static BigDecimal createBigDecimal(String val) {
          BigDecimal bd = new BigDecimal(val);
          return bd;
      }
  
      //--------------------------------------------------------------------
      
      /**
       * <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 minimum(long a, long b, 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 minimum(int a, int b, int c) {
          if (b < a) {
              a = b;
          }
          if (c < a) {
              a = c;
          }
          return a;
      }
  
      /**
       * <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 maximum(long a, long b, 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 maximum(int a, int b, int c) {
          if (b > a) {
              a = b;
          }
          if (c > a) {
              a = c;
          }
          return a;
      }
  
      //--------------------------------------------------------------------
      
      /**
       * <p>Compares two <code>doubles</code> for order.</p>
       *
       * <p>This method is more comprehensive than the standard Java greater
       * than, less than and equals operators.</p>
       * <ul>
       *  <li>It returns <code>-1</code> if the first value is less than the second.
       *  <li>It returns <code>+1</code> if the first value is greater than the second.
       *  <li>It returns <code>0</code> if the values are equal.
       * </ul>
       *
       * <p>
       * The ordering is as follows, largest to smallest:
       * <ul>
       *  <li>NaN
       *  <li>Positive infinity
       *  <li>Maximum double
       *  <li>Normal positive numbers
       *  <li>+0.0
       *  <li>-0.0
       *  <li>Normal negative numbers
       *  <li>Minimum double (-Double.MAX_VALUE)
       *  <li>Negative infinity
       * </ul>
       * </p>
       *
       * <p>Comparing <code>NaN</code> with <code>NaN</code> will
       * return <code>0</code>.</p>
       * 
       * @param lhs  the first <code>double</code>
       * @param rhs  the second <code>double</code>
       * @return <code>-1</code> if lhs is less, <code>+1</code> if greater,
       *  <code>0</code> if equal to rhs
       */
      public static int compare(double lhs, double rhs) {
          if (lhs < rhs) {
              return -1;
          }
          if (lhs > rhs) {
              return +1;
          }
          // Need to compare bits to handle 0.0 == -0.0 being true
          // compare should put -0.0 < +0.0
          // Two NaNs are also == for compare purposes
          // where NaN == NaN is false
          long lhsBits = Double.doubleToLongBits(lhs);
          long rhsBits = Double.doubleToLongBits(rhs);
          if (lhsBits == rhsBits) {
              return 0;
          }
          // Something exotic! A comparison to NaN or 0.0 vs -0.0
          // Fortunately NaN's long is > than everything else
          // Also negzeros bits < poszero
          // NAN: 9221120237041090560
          // MAX: 9218868437227405311
          // NEGZERO: -9223372036854775808
          if (lhsBits < rhsBits) {
              return -1;
          } else {
              return +1;
          }
      }
      
      /**
       * <p>Compares two floats for order.</p>
       *
       * <p>This method is more comprehensive than the standard Java greater than,
       * less than and equals operators.</p>
       * <ul>
       *  <li>It returns <code>-1</code> if the first value is less than the second.
       *  <li>It returns <code>+1</code> if the first value is greater than the second.
       *  <li>It returns <code>0</code> if the values are equal.
       * </ul>
       *
       * <p> The ordering is as follows, largest to smallest:
       * <ul>
       * <li>NaN
       * <li>Positive infinity
       * <li>Maximum float
       * <li>Normal positive numbers
       * <li>+0.0
       * <li>-0.0
       * <li>Normal negative numbers
       * <li>Minimum float (-Float.MAX_VALUE)
       * <li>Negative infinity
       * </ul>
       *
       * <p>Comparing <code>NaN</code> with <code>NaN</code> will return
       * <code>0</code>.</p>
       * 
       * @param lhs  the first <code>float</code>
       * @param rhs  the second <code>float</code>
       * @return <code>-1</code> if lhs is less, <code>+1</code> if greater,
       *  <code>0</code> if equal to rhs
       */
      public static int compare(float lhs, float rhs) {
          if (lhs < rhs) {
              return -1;
          }
          if (lhs > rhs) {
              return +1;
          }
          //Need to compare bits to handle 0.0 == -0.0 being true
          // compare should put -0.0 < +0.0
          // Two NaNs are also == for compare purposes
          // where NaN == NaN is false
          int lhsBits = Float.floatToIntBits(lhs);
          int rhsBits = Float.floatToIntBits(rhs);
          if (lhsBits == rhsBits) {
              return 0;
          }
          //Something exotic! A comparison to NaN or 0.0 vs -0.0
          //Fortunately NaN's int is > than everything else
          //Also negzeros bits < poszero
          //NAN: 2143289344
          //MAX: 2139095039
          //NEGZERO: -2147483648
          if (lhsBits < rhsBits) {
              return -1;
          } else {
              return +1;
          }
      }
      
      //--------------------------------------------------------------------
      
      /**
       * <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(String str) {
          if ((str == null) || (str.length() == 0)) {
              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(String str) {
          if (StringUtils.isEmpty(str)) {
              return false;
          }
          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
          int start = (chars[0] == '-') ? 1 : 0;
          if (sz > start + 1) {
              if (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 (!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
                  return foundDigit && !hasExp;
              }
              // 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;
      }
  }
  