/* ====================================================================
    * The Apache Software License, Version 1.1
    *
    * Copyright (c) 2002 The Apache Software Foundation.  All rights
    * reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowlegement:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.codehaus.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "The Jakarta Project", "Commons", and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written
   *    permission, please contact codehaus@codehaus.org.
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.codehaus.org/>.
   */
  package org.codehaus.plexus.util;
  
  import java.util.Arrays;
  import java.util.Iterator;
  import java.util.Locale;
  import java.util.Map;
  import java.util.StringTokenizer;
  
  /**
   * <p>Common <code>String</code> manipulation routines.</p>
   *
   * <p>Originally from
   * <a href="http://jakarta.apache.org/turbine/">Turbine</a> and the
   * GenerationJavaCore library.</p>
   *
   * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
   * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
   * @author <a href="mailto:gcoladonato@yahoo.com">Greg Coladonato</a>
   * @author <a href="mailto:bayard@generationjava.com">Henri Yandell</a>
   * @author <a href="mailto:ed@codehaus.org">Ed Korthof</a>
   * @author <a href="mailto:rand_mcneely@yahoo.com">Rand McNeely</a>
   * @author Stephen Colebourne
   * @author <a href="mailto:fredrik@westermarck.com">Fredrik Westermarck</a>
   * @author Holger Krauth
   * @author <a href="mailto:alex@purpletech.com">Alexander Day Chaffee</a>
   * @author <a href="mailto:vincent.siveton@gmail.com">Vincent Siveton</a>
   * @since 1.0
   * @version $Id$
   */
  public class StringUtils
  {
      /**
       * <p><code>StringUtils</code> instances should NOT be constructed in
       * standard programming. Instead, the class should be used as
       * <code>StringUtils.trim(" foo ");</code>.</p>
       *
       * <p>This constructor is public to permit tools that require a JavaBean
       * manager to operate.</p>
       */
      public StringUtils()
      {
      }
  
      // Empty
      //--------------------------------------------------------------------------
  
     /**
      * <p>Removes control characters, including whitespace, from both
      * ends of this String, handling <code>null</code> by returning
      * an empty String.</p>
      *
      * @see java.lang.String#trim()
      * @param str the String to check
      * @return the trimmed text (never <code>null</code>)
      */
     public static String clean( String str )
     {
         return ( str == null ? "" : str.trim() );
     }
 
     /**
      * <p>Removes control characters, including whitespace, from both
      * ends of this String, handling <code>null</code> by returning
      * <code>null</code>.</p>
      *
      * @see java.lang.String#trim()
      * @param str the String to check
      * @return the trimmed text (or <code>null</code>)
      */
     public static String trim( String str )
     {
         return ( str == null ? null : str.trim() );
     }
 
     /**
      * <p>Deletes all whitespaces from a String.</p>
      *
      * <p>Whitespace is defined by
      * {@link Character#isWhitespace(char)}.</p>
      *
      * @param str String target to delete whitespace from
      * @return the String without whitespaces
      * @throws NullPointerException
      */
     public static String deleteWhitespace( String str )
     {
         StringBuilder buffer = new StringBuilder();
         int sz = str.length();
         for ( int i = 0; i < sz; i++ )
         {
             if ( !Character.isWhitespace( str.charAt( i ) ) )
             {
                 buffer.append( str.charAt( i ) );
             }
         }
         return buffer.toString();
     }
 
     /**
      * <p>Checks if a String is non <code>null</code> and is
      * not empty (<code>length &lt; 0</code>).</p>
      *
      * @param str the String to check
      * @return true if the String is non-null, and not length zero
      */
     public static boolean isNotEmpty( String str )
     {
         return ( ( str != null ) && ( str.length() > 0 ) );
     }
 
     /**
      * <p>Checks if a (trimmed) String is <code>null</code> or empty.</p>
      *
      * <p><strong>Note:</strong> In future releases, this method will no longer trim the input string such that it works
      * complementary to {@link #isNotEmpty(String)}. Code that wants to test for whitespace-only strings should be
      * migrated to use {@link #isBlank(String)} instead.</p>
      *
      * @param str the String to check
      * @return <code>true</code> if the String is <code>null</code>, or
      *  length zero once trimmed
      */
     public static boolean isEmpty( String str )
     {
         return ( ( str == null ) || ( str.trim().length() == 0 ) );
     }
 
     /**
      * <p>
      * Checks if a String is whitespace, empty ("") or null.
      * </p>
      *
      * <pre>
      * StringUtils.isBlank(null)      = true
      * StringUtils.isBlank("")        = true
      * StringUtils.isBlank(" ")       = true
      * StringUtils.isBlank("bob")     = false
      * StringUtils.isBlank("  bob  ") = false
      * </pre>
      *
      * @param str the String to check, may be null
      * @return <code>true</code> if the String is null, empty or whitespace
      * @since 1.5.2
      */
     public static boolean isBlank( String str )
     {
         int strLen;
         if ( str == null || ( strLen = str.length() ) == 0 )
         {
             return true;
         }
         for ( int i = 0; i < strLen; i++ )
         {
             if ( !Character.isWhitespace( str.charAt( i ) ) )
             {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * <p>
      * Checks if a String is not empty (""), not null and not whitespace only.
      * </p>
      *
      * <pre>
      * StringUtils.isNotBlank(null)      = false
      * StringUtils.isNotBlank("")        = false
      * StringUtils.isNotBlank(" ")       = false
      * StringUtils.isNotBlank("bob")     = true
      * StringUtils.isNotBlank("  bob  ") = true
      * </pre>
      *
      * @param str the String to check, may be null
      * @return <code>true</code> if the String is not empty and not null and not whitespace
      * @since 1.5.2
      */
     public static boolean isNotBlank( String str )
     {
         return !StringUtils.isBlank( str );
     }
 
     // Equals and IndexOf
     //--------------------------------------------------------------------------
 
     /**
      * <p>Compares two Strings, returning <code>true</code> if they are equal.</p>
      *
      * <p><code>null</code>s are handled without exceptions. Two <code>null</code>
      * references are considered to be equal. The comparison is case sensitive.</p>
      *
      * @see java.lang.String#equals(Object)
      * @param str1 the first string
      * @param str2 the second string
      * @return <code>true</code> if the Strings are equal, case sensitive, or
      *  both <code>null</code>
      */
     public static boolean equals( String str1, String str2 )
     {
         return ( str1 == null ? str2 == null : str1.equals( str2 ) );
     }
 
     /**
      * <p>Compares two Strings, returning <code>true</code> if they are equal ignoring
      * the case.</p>
      *
      * <p><code>Nulls</code> are handled without exceptions. Two <code>null</code>
      * references are considered equal. Comparison is case insensitive.</p>
      *
      * @see java.lang.String#equalsIgnoreCase(String)
      * @param str1  the first string
      * @param str2  the second string
      * @return <code>true</code> if the Strings are equal, case insensitive, or
      *  both <code>null</code>
      */
     public static boolean equalsIgnoreCase( String str1, String str2 )
     {
         return ( str1 == null ? str2 == null : str1.equalsIgnoreCase( str2 ) );
     }
 
     /**
      * <p>Find the first index of any of a set of potential substrings.</p>
      *
      * <p><code>null</code> String will return <code>-1</code>.</p>
      *
      * @param str the String to check
      * @param searchStrs the Strings to search for
      * @return the first index of any of the searchStrs in str
      * @throws NullPointerException if any of searchStrs[i] is <code>null</code>
      */
     public static int indexOfAny( String str, String[] searchStrs )
     {
         if ( ( str == null ) || ( searchStrs == null ) )
         {
             return -1;
         }
         int sz = searchStrs.length;
 
         // String's can't have a MAX_VALUEth index.
         int ret = Integer.MAX_VALUE;
 
         int tmp;
         for ( String searchStr : searchStrs )
         {
             tmp = str.indexOf( searchStr );
             if ( tmp == -1 )
             {
                 continue;
             }
 
             if ( tmp < ret )
             {
                 ret = tmp;
             }
         }
 
         return ( ret == Integer.MAX_VALUE ) ? -1 : ret;
     }
 
     /**
      * <p>Find the latest index of any of a set of potential substrings.</p>
      *
      * <p><code>null</code> string will return <code>-1</code>.</p>
      *
      * @param str  the String to check
      * @param searchStrs  the Strings to search for
      * @return the last index of any of the Strings
      * @throws NullPointerException if any of searchStrs[i] is <code>null</code>
      */
     public static int lastIndexOfAny( String str, String[] searchStrs )
     {
         if ( ( str == null ) || ( searchStrs == null ) )
         {
             return -1;
         }
         int ret = -1;
         int tmp;
         for ( String searchStr : searchStrs )
         {
             tmp = str.lastIndexOf( searchStr );
             if ( tmp > ret )
             {
                 ret = tmp;
             }
         }
         return ret;
     }
 
     // Substring
     //--------------------------------------------------------------------------
 
     /**
      * <p>Gets a substring from the specified string avoiding exceptions.</p>
      *
      * <p>A negative start position can be used to start <code>n</code>
      * characters from the end of the String.</p>
      *
      * @param str the String to get the substring from
      * @param start the position to start from, negative means
      *  count back from the end of the String by this many characters
      * @return substring from start position
      */
     public static String substring( String str, int start )
     {
         if ( str == null )
         {
             return null;
         }
 
         // handle negatives, which means last n characters
         if ( start < 0 )
         {
             start = str.length() + start; // remember start is negative
         }
 
         if ( start < 0 )
         {
             start = 0;
         }
         if ( start > str.length() )
         {
             return "";
         }
 
         return str.substring( start );
     }
 
     /**
      * <p>Gets a substring from the specified String avoiding exceptions.</p>
      *
      * <p>A negative start position can be used to start/end <code>n</code>
      * characters from the end of the String.</p>
      *
      * @param str the String to get the substring from
      * @param start the position to start from, negative means
      *  count back from the end of the string by this many characters
      * @param end the position to end at (exclusive), negative means
      *  count back from the end of the String by this many characters
      * @return substring from start position to end positon
      */
     public static String substring( String str, int start, int end )
     {
         if ( str == null )
         {
             return null;
         }
 
         // handle negatives
         if ( end < 0 )
         {
             end = str.length() + end; // remember end is negative
         }
         if ( start < 0 )
         {
             start = str.length() + start; // remember start is negative
         }
 
         // check length next
         if ( end > str.length() )
         {
             // check this works.
             end = str.length();
         }
 
         // if start is greater than end, return ""
         if ( start > end )
         {
             return "";
         }
 
         if ( start < 0 )
         {
             start = 0;
         }
         if ( end < 0 )
         {
             end = 0;
         }
 
         return str.substring( start, end );
     }
 
     /**
      * <p>Gets the leftmost <code>n</code> characters of a String.</p>
      *
      * <p>If <code>n</code> characters are not available, or the
      * String is <code>null</code>, the String will be returned without
      * an exception.</p>
      *
      * @param str the String to get the leftmost characters from
      * @param len the length of the required String
      * @return the leftmost characters
      * @throws IllegalArgumentException if len is less than zero
      */
     public static String left( String str, int len )
     {
         if ( len < 0 )
         {
             throw new IllegalArgumentException( "Requested String length " + len + " is less than zero" );
         }
         if ( ( str == null ) || ( str.length() <= len ) )
         {
             return str;
         }
         else
         {
             return str.substring( 0, len );
         }
     }
 
     /**
      * <p>Gets the rightmost <code>n</code> characters of a String.</p>
      *
      * <p>If <code>n</code> characters are not available, or the String
      * is <code>null</code>, the String will be returned without an
      * exception.</p>
      *
      * @param str the String to get the rightmost characters from
      * @param len the length of the required String
      * @return the leftmost characters
      * @throws IllegalArgumentException if len is less than zero
      */
     public static String right( String str, int len )
     {
         if ( len < 0 )
         {
             throw new IllegalArgumentException( "Requested String length " + len + " is less than zero" );
         }
         if ( ( str == null ) || ( str.length() <= len ) )
         {
             return str;
         }
         else
         {
             return str.substring( str.length() - len );
         }
     }
 
     /**
      * <p>Gets <code>n</code> characters from the middle of a String.</p>
      *
      * <p>If <code>n</code> characters are not available, the remainder
      * of the String will be returned without an exception. If the
      * String is <code>null</code>, <code>null</code> will be returned.</p>
      *
      * @param str the String to get the characters from
      * @param pos the position to start from
      * @param len the length of the required String
      * @return the leftmost characters
      * @throws IndexOutOfBoundsException if pos is out of bounds
      * @throws IllegalArgumentException if len is less than zero
      */
     public static String mid( String str, int pos, int len )
     {
         if ( ( pos < 0 ) ||
             ( ( str != null ) && ( pos > str.length() ) ) )
         {
             throw new StringIndexOutOfBoundsException( "String index " + pos + " is out of bounds" );
         }
         if ( len < 0 )
         {
             throw new IllegalArgumentException( "Requested String length " + len + " is less than zero" );
         }
         if ( str == null )
         {
             return null;
         }
         if ( str.length() <= ( pos + len ) )
         {
             return str.substring( pos );
         }
         else
         {
             return str.substring( pos, pos + len );
         }
     }
 
     // Splitting
     //--------------------------------------------------------------------------
 
     /**
      * <p>Splits the provided text into a array, using whitespace as the
      * separator.</p>
      *
      * <p>The separator is not included in the returned String array.</p>
      *
      * @param str the String to parse
      * @return an array of parsed Strings
      */
     public static String[] split( String str )
     {
         return split( str, null, -1 );
     }
 
     /**
      * @see #split(String, String, int)
      */
     public static String[] split( String text, String separator )
     {
         return split( text, separator, -1 );
     }
 
     /**
      * <p>Splits the provided text into a array, based on a given separator.</p>
      *
      * <p>The separator is not included in the returned String array. The
      * maximum number of splits to perfom can be controlled. A <code>null</code>
      * separator will cause parsing to be on whitespace.</p>
      *
      * <p>This is useful for quickly splitting a String directly into
      * an array of tokens, instead of an enumeration of tokens (as
      * <code>StringTokenizer</code> does).</p>
      *
      * @param str The string to parse.
      * @param separator Characters used as the delimiters. If
      *  <code>null</code>, splits on whitespace.
      * @param max The maximum number of elements to include in the
      *  array.  A zero or negative value implies no limit.
      * @return an array of parsed Strings
      */
     public static String[] split( String str, String separator, int max )
     {
         StringTokenizer tok;
         if ( separator == null )
         {
             // Null separator means we're using StringTokenizer's default
             // delimiter, which comprises all whitespace characters.
             tok = new StringTokenizer( str );
         }
         else
         {
             tok = new StringTokenizer( str, separator );
         }
 
         int listSize = tok.countTokens();
         if ( ( max > 0 ) && ( listSize > max ) )
         {
             listSize = max;
         }
 
         String[] list = new String[listSize];
         int i = 0;
         int lastTokenBegin;
         int lastTokenEnd = 0;
         while ( tok.hasMoreTokens() )
         {
             if ( ( max > 0 ) && ( i == listSize - 1 ) )
             {
                 // In the situation where we hit the max yet have
                 // tokens left over in our input, the last list
                 // element gets all remaining text.
                 String endToken = tok.nextToken();
                 lastTokenBegin = str.indexOf( endToken, lastTokenEnd );
                 list[i] = str.substring( lastTokenBegin );
                 break;
             }
             else
             {
                 list[i] = tok.nextToken();
                 lastTokenBegin = str.indexOf( list[i], lastTokenEnd );
                 lastTokenEnd = lastTokenBegin + list[i].length();
             }
             i++;
         }
         return list;
     }
 
     // Joining
     //--------------------------------------------------------------------------
     /**
      * <p>Concatenates elements of an array into a single String.</p>
      *
      * <p>The difference from join is that concatenate has no delimiter.</p>
      *
      * @param array the array of values to concatenate.
      * @return the concatenated string.
      */
     public static String concatenate( Object[] array )
     {
         return join( array, "" );
     }
 
     /**
      * <p>Joins the elements of the provided array into a single String
      * containing the provided list of elements.</p>
      *
      * <p>No delimiter is added before or after the list. A
      * <code>null</code> separator is the same as a blank String.</p>
      *
      * @param array the array of values to join together
      * @param separator the separator character to use
      * @return the joined String
      */
     public static String join( Object[] array, String separator )
     {
         if ( separator == null )
         {
             separator = "";
         }
         int arraySize = array.length;
         int bufSize = ( arraySize == 0 ? 0 : ( array[0].toString().length() +
             separator.length() ) * arraySize );
         StringBuilder buf = new StringBuilder( bufSize );
 
         for ( int i = 0; i < arraySize; i++ )
         {
             if ( i > 0 )
             {
                 buf.append( separator );
             }
             buf.append( array[i] );
         }
         return buf.toString();
     }
 
     /**
      * <p>Joins the elements of the provided <code>Iterator</code> into
      * a single String containing the provided elements.</p>
      *
      * <p>No delimiter is added before or after the list. A
      * <code>null</code> separator is the same as a blank String.</p>
      *
      * @param iterator the <code>Iterator</code> of values to join together
      * @param separator  the separator character to use
      * @return the joined String
      */
     public static String join( Iterator<?> iterator, String separator )
     {
         if ( separator == null )
         {
             separator = "";
         }
         StringBuilder buf = new StringBuilder( 256 );  // Java default is 16, probably too small
         while ( iterator.hasNext() )
         {
             buf.append( iterator.next() );
             if ( iterator.hasNext() )
             {
                 buf.append( separator );
             }
         }
         return buf.toString();
     }
 
 
 
     // Replacing
     //--------------------------------------------------------------------------
 
     /**
      * <p>Replace a char with another char inside a larger String, once.</p>
      *
      * <p>A <code>null</code> reference passed to this method is a no-op.</p>
      *
      * @see #replace(String text, char repl, char with, int max)
      * @param text text to search and replace in
      * @param repl char to search for
      * @param with char to replace with
      * @return the text with any replacements processed
      */
     public static String replaceOnce( String text, char repl, char with )
     {
         return replace( text, repl, with, 1 );
     }
 
     /**
      * <p>Replace all occurances of a char within another char.</p>
      *
      * <p>A <code>null</code> reference passed to this method is a no-op.</p>
      *
      * @see #replace(String text, char repl, char with, int max)
      * @param text text to search and replace in
      * @param repl char to search for
      * @param with char to replace with
      * @return the text with any replacements processed
      */
     public static String replace( String text, char repl, char with )
     {
         return replace( text, repl, with, -1 );
     }
 
     /**
      * <p>Replace a char with another char inside a larger String,
      * for the first <code>max</code> values of the search char.</p>
      *
      * <p>A <code>null</code> reference passed to this method is a no-op.</p>
      *
      * @param text text to search and replace in
      * @param repl char to search for
      * @param with char to replace with
      * @param max maximum number of values to replace, or <code>-1</code> if no maximum
      * @return the text with any replacements processed
      */
     public static String replace( String text, char repl, char with, int max )
     {
         return replace( text, String.valueOf( repl ), String.valueOf( with ), max );
     }
 
     /**
      * <p>Replace a String with another String inside a larger String, once.</p>
      *
      * <p>A <code>null</code> reference passed to this method is a no-op.</p>
      *
      * @see #replace(String text, String repl, String with, int max)
      * @param text text to search and replace in
      * @param repl String to search for
      * @param with String to replace with
      * @return the text with any replacements processed
      */
     public static String replaceOnce( String text, String repl, String with )
     {
         return replace( text, repl, with, 1 );
     }
 
     /**
      * <p>Replace all occurances of a String within another String.</p>
      *
      * <p>A <code>null</code> reference passed to this method is a no-op.</p>
      *
      * @see #replace(String text, String repl, String with, int max)
      * @param text text to search and replace in
      * @param repl String to search for
      * @param with String to replace with
      * @return the text with any replacements processed
      */
     public static String replace( String text, String repl, String with )
     {
         return replace( text, repl, with, -1 );
     }
 
     /**
      * <p>Replace a String with another String inside a larger String,
      * for the first <code>max</code> values of the search String.</p>
      *
      * <p>A <code>null</code> reference passed to this method is a no-op.</p>
      *
      * @param text text to search and replace in
      * @param repl String to search for
      * @param with String to replace with
      * @param max maximum number of values to replace, or <code>-1</code> if no maximum
      * @return the text with any replacements processed
      */
     public static String replace( String text, String repl, String with, int max )
     {
         if ( ( text == null ) || ( repl == null ) || ( with == null ) || ( repl.length() == 0 ) )
         {
             return text;
         }
 
         StringBuilder buf = new StringBuilder( text.length() );
         int start = 0, end;
         while ( ( end = text.indexOf( repl, start ) ) != -1 )
         {
             buf.append( text, start, end ).append( with );
             start = end + repl.length();
 
             if ( --max == 0 )
             {
                 break;
             }
         }
         buf.append( text, start, text.length());
         return buf.toString();
     }
 
     /**
      * <p>Overlay a part of a String with another String.</p>
      *
      * @param text String to do overlaying in
      * @param overlay String to overlay
      * @param start int to start overlaying at
      * @param end int to stop overlaying before
      * @return String with overlayed text
      * @throws NullPointerException if text or overlay is <code>null</code>
      */
     public static String overlayString( String text, String overlay, int start, int end )
     {
         return new StringBuffer( start + overlay.length() + text.length() - end + 1 )
             .append( text, 0, start  )
             .append( overlay )
             .append( text, end, text.length() )
             .toString();
     }
 
     // Centering
     //--------------------------------------------------------------------------
 
     /**
      * <p>Center a String in a larger String of size <code>n</code>.<p>
      *
      * <p>Uses spaces as the value to buffer the String with.
      * Equivalent to <code>center(str, size, " ")</code>.</p>
      *
      * @param str String to center
      * @param size int size of new String
      * @return String containing centered String
      * @throws NullPointerException if str is <code>null</code>
      */
     public static String center( String str, int size )
     {
         return center( str, size, " " );
     }
 
     /**
      * <p>Center a String in a larger String of size <code>n</code>.</p>
      *
      * <p>Uses a supplied String as the value to buffer the String with.</p>
      *
      * @param str String to center
      * @param size int size of new String
      * @param delim String to buffer the new String with
      * @return String containing centered String
      * @throws NullPointerException if str or delim is <code>null</code>
      * @throws ArithmeticException if delim is the empty String
      */
     public static String center( String str, int size, String delim )
     {
         int sz = str.length();
         int p = size - sz;
         if ( p < 1 )
         {
             return str;
         }
         str = leftPad( str, sz + p / 2, delim );
         str = rightPad( str, size, delim );
         return str;
     }
 
     // Chomping
     //--------------------------------------------------------------------------
 
     /**
      * <p>Remove the last newline, and everything after it from a String.</p>
      *
      * @param str String to chomp the newline from
      * @return String without chomped newline
      * @throws NullPointerException if str is <code>null</code>
      */
     public static String chomp( String str )
     {
         return chomp( str, "\n" );
     }
 
     /**
      * <p>Remove the last value of a supplied String, and everything after
      * it from a String.</p>
      *
      * @param str String to chomp from
      * @param sep String to chomp
      * @return String without chomped ending
      * @throws NullPointerException if str or sep is <code>null</code>
      */
     public static String chomp( String str, String sep )
     {
         int idx = str.lastIndexOf( sep );
         if ( idx != -1 )
         {
             return str.substring( 0, idx );
         }
         else
         {
             return str;
         }
     }
 
     /**
      * <p>Remove a newline if and only if it is at the end
      * of the supplied String.</p>
      *
      * @param str String to chomp from
      * @return String without chomped ending
      * @throws NullPointerException if str is <code>null</code>
      */
     public static String chompLast( String str )
     {
         return chompLast( str, "\n" );
     }
 
     /**
      * <p>Remove a value if and only if the String ends with that value.</p>
      *
      * @param str String to chomp from
      * @param sep String to chomp
      * @return String without chomped ending
      * @throws NullPointerException if str or sep is <code>null</code>
      */
     public static String chompLast( String str, String sep )
     {
         if ( str.length() == 0 )
         {
             return str;
         }
         String sub = str.substring( str.length() - sep.length() );
         if ( sep.equals( sub ) )
         {
             return str.substring( 0, str.length() - sep.length() );
         }
         else
         {
             return str;
         }
     }
 
     /**
      * <p>Remove everything and return the last value of a supplied String, and
      * everything after it from a String.</p>
      *
      * @param str String to chomp from
      * @param sep String to chomp
      * @return String chomped
      * @throws NullPointerException if str or sep is <code>null</code>
      */
     public static String getChomp( String str, String sep )
     {
         int idx = str.lastIndexOf( sep );
         if ( idx == str.length() - sep.length() )
         {
             return sep;
         }
         else if ( idx != -1 )
         {
             return str.substring( idx );
         }
         else
         {
             return "";
         }
     }
 
     /**
      * <p>Remove the first value of a supplied String, and everything before it
      * from a String.</p>
      *
      * @param str String to chomp from
      * @param sep String to chomp
      * @return String without chomped beginning
      * @throws NullPointerException if str or sep is <code>null</code>
      */
     public static String prechomp( String str, String sep )
     {
         int idx = str.indexOf( sep );
         if ( idx != -1 )
         {
             return str.substring( idx + sep.length() );
         }
         else
         {
             return str;
         }
     }
 
     /**
      * <p>Remove and return everything before the first value of a
      * supplied String from another String.</p>
      *
      * @param str String to chomp from
      * @param sep String to chomp
      * @return String prechomped
      * @throws NullPointerException if str or sep is <code>null</code>
      */
     public static String getPrechomp( String str, String sep )
     {
         int idx = str.indexOf( sep );
         if ( idx != -1 )
         {
             return str.substring( 0, idx + sep.length() );
         }
         else
         {
             return "";
         }
     }
 
     // Chopping
     //--------------------------------------------------------------------------
 
     /**
      * <p>Remove the last character from a String.</p>
      *
      * <p>If the String ends in <code>\r\n</code>, then remove both
      * of them.</p>
      *
      * @param str String to chop last character from
      * @return String without last character
      * @throws NullPointerException if str is <code>null</code>
      */
     public static String chop( String str )
     {
         if ( "".equals( str ) )
         {
             return "";
         }
         if ( str.length() == 1 )
         {
             return "";
         }
         int lastIdx = str.length() - 1;
         String ret = str.substring( 0, lastIdx );
         char last = str.charAt( lastIdx );
         if ( last == '\n' )
         {
             if ( ret.charAt( lastIdx - 1 ) == '\r' )
             {
                 return ret.substring( 0, lastIdx - 1 );
             }
         }
         return ret;
     }
 
     /**
      * <p>Remove <code>\n</code> from end of a String if it's there.
      * If a <code>\r</code> precedes it, then remove that too.</p>
      *
      * @param str String to chop a newline from
      * @return String without newline
      * @throws NullPointerException if str is <code>null</code>
      */
     public static String chopNewline( String str )
     {
         int lastIdx = str.length() - 1;
         char last = str.charAt( lastIdx );
         if ( last == '\n' )
         {
             if ( str.charAt( lastIdx - 1 ) == '\r' )
             {
                 lastIdx--;
             }
         }
         else
         {
             lastIdx++;
         }
         return str.substring( 0, lastIdx );
     }
 
 
     // Conversion
     //--------------------------------------------------------------------------
 
     // spec 3.10.6
     /**
      * <p>Escapes any values it finds into their String form.</p>
      *
      * <p>So a tab becomes the characters <code>'\\'</code> and
      * <code>'t'</code>.</p>
      *
      * @param str String to escape values in
      * @return String with escaped values
      * @throws NullPointerException if str is <code>null</code>
      */
     public static String escape( String str )
     {
         // improved with code from  cybertiger@cyberiantiger.org
         // unicode from him, and defaul for < 32's.
         int sz = str.length();
         StringBuilder buffer = new StringBuilder( 2 * sz );
         for ( int i = 0; i < sz; i++ )
         {
             char ch = str.charAt( i );
 
             // handle unicode
             if ( ch > 0xfff )
             {
                 buffer.append( "\\u" + Integer.toHexString( ch ) );
             }
             else if ( ch > 0xff )
             {
                 buffer.append( "\\u0" + Integer.toHexString( ch ) );
             }
             else if ( ch > 0x7f )
             {
                 buffer.append( "\\u00" + Integer.toHexString( ch ) );
             }
             else if ( ch < 32 )
             {
                 switch ( ch )
                 {
                     case '\b':
                         buffer.append( '\\' );
                         buffer.append( 'b' );
                         break;
                     case '\n':
                         buffer.append( '\\' );
                         buffer.append( 'n' );
                         break;
                     case '\t':
                         buffer.append( '\\' );
                         buffer.append( 't' );
                         break;
                     case '\f':
                         buffer.append( '\\' );
                         buffer.append( 'f' );
                         break;
                     case '\r':
                         buffer.append( '\\' );
                         buffer.append( 'r' );
                         break;
                     default :
                         if ( ch > 0xf )
                         {
                             buffer.append( "\\u00" + Integer.toHexString( ch ) );
                         }
                         else
                         {
                             buffer.append( "\\u000" + Integer.toHexString( ch ) );
                         }
                         break;
                 }
             }
             else
             {
                 switch ( ch )
                 {
                     case '\'':
                         buffer.append( '\\' );
                         buffer.append( '\'' );
                         break;
                     case '"':
                         buffer.append( '\\' );
                         buffer.append( '"' );
                         break;
                     case '\\':
                         buffer.append( '\\' );
                         buffer.append( '\\' );
                         break;
                     default :
                         buffer.append( ch );
                         break;
                 }
             }
         }
         return buffer.toString();
     }
 
     // Padding
     //--------------------------------------------------------------------------
 
     /**
      * <p>Repeat a String <code>n</code> times to form a
      * new string.</p>
      *
      * @param str String to repeat
      * @param repeat number of times to repeat str
      * @return String with repeated String
      * @throws NegativeArraySizeException if <code>repeat &lt; 0</code>
      * @throws NullPointerException if str is <code>null</code>
      */
     public static String repeat( String str, int repeat )
     {
         StringBuilder buffer = new StringBuilder( repeat * str.length() );
         for ( int i = 0; i < repeat; i++ )
         {
             buffer.append( str );
         }
         return buffer.toString();
     }
 
     /**
      * <p>Right pad a String with spaces.</p>
      *
      * <p>The String is padded to the size of <code>n</code>.</p>
      *
      * @param str String to repeat
      * @param size number of times to repeat str
      * @return right padded String
      * @throws NullPointerException if str is <code>null</code>
      */
     public static String rightPad( String str, int size )
     {
         return rightPad( str, size, " " );
     }
 
     /**
      * <p>Right pad a String with a specified string.</p>
      *
      * <p>The String is padded to the size of <code>n</code>.</p>
      *
      * @param str String to pad out
      * @param size size to pad to
      * @param delim String to pad with
      * @return right padded String
      * @throws NullPointerException if str or delim is <code>null</code>
      * @throws ArithmeticException if delim is the empty String
      */
     public static String rightPad( String str, int size, String delim )
     {
         size = ( size - str.length() ) / delim.length();
         if ( size > 0 )
         {
             str += repeat( delim, size );
         }
         return str;
     }
 
     /**
      * <p>Left pad a String with spaces.</p>
      *
      * <p>The String is padded to the size of <code>n</code>.</p>
      *
      * @param str String to pad out
      * @param size size to pad to
      * @return left padded String
      * @throws NullPointerException if str or delim is <code>null</code>
      */
     public static String leftPad( String str, int size )
     {
         return leftPad( str, size, " " );
     }
 
     /**
      * Left pad a String with a specified string. Pad to a size of n.
      *
      * @param str String to pad out
      * @param size size to pad to
      * @param delim String to pad with
      * @return left padded String
      * @throws NullPointerException if str or delim is null
      * @throws ArithmeticException if delim is the empty string
      */
     public static String leftPad( String str, int size, String delim )
     {
         size = ( size - str.length() ) / delim.length();
         if ( size > 0 )
         {
             str = repeat( delim, size ) + str;
         }
         return str;
     }
 
     // Stripping
     //--------------------------------------------------------------------------
 
     /**
      * <p>Remove whitespace from the front and back of a String.</p>
      *
      * @param str the String to remove whitespace from
      * @return the stripped String
      */
     public static String strip( String str )
     {
         return strip( str, null );
     }
 
     /**
      * <p>Remove a specified String from the front and back of a
      * String.</p>
      *
      * <p>If whitespace is wanted to be removed, used the
      * {@link #strip(java.lang.String)} method.</p>
      *
      * @param str the String to remove a string from
      * @param delim the String to remove at start and end
      * @return the stripped String
      */
     public static String strip( String str, String delim )
     {
         str = stripStart( str, delim );
         return stripEnd( str, delim );
     }
 
     /**
      * <p>Strip whitespace from the front and back of every String
      * in the array.</p>
      *
      * @param strs the Strings to remove whitespace from
      * @return the stripped Strings
      */
     public static String[] stripAll( String[] strs )
     {
         return stripAll( strs, null );
     }
 
     /**
      * <p>Strip the specified delimiter from the front and back of
      * every String in the array.</p>
      *
      * @param strs the Strings to remove a String from
      * @param delimiter the String to remove at start and end
      * @return the stripped Strings
      */
     public static String[] stripAll( String[] strs, String delimiter )
     {
         if ( ( strs == null ) || ( strs.length == 0 ) )
         {
             return strs;
         }
         int sz = strs.length;
         String[] newArr = new String[sz];
         for ( int i = 0; i < sz; i++ )
         {
             newArr[i] = strip( strs[i], delimiter );
         }
         return newArr;
     }
 
     /**
      * <p>Strip any of a supplied String from the end of a String.</p>
      *
      * <p>If the strip String is <code>null</code>, whitespace is
      * stripped.</p>
      *
      * @param str the String to remove characters from
      * @param strip the String to remove
      * @return the stripped String
      */
     public static String stripEnd( String str, String strip )
     {
         if ( str == null )
         {
             return null;
         }
         int end = str.length();
 
         if ( strip == null )
         {
             while ( ( end != 0 ) && Character.isWhitespace( str.charAt( end - 1 ) ) )
             {
                 end--;
             }
         }
         else
         {
             while ( ( end != 0 ) && ( strip.indexOf( str.charAt( end - 1 ) ) != -1 ) )
             {
                 end--;
             }
         }
         return str.substring( 0, end );
     }
 
     /**
      * <p>Strip any of a supplied String from the start of a String.</p>
      *
      * <p>If the strip String is <code>null</code>, whitespace is
      * stripped.</p>
      *
      * @param str the String to remove characters from
      * @param strip the String to remove
      * @return the stripped String
      */
     public static String stripStart( String str, String strip )
     {
         if ( str == null )
         {
             return null;
         }
 
         int start = 0;
 
         int sz = str.length();
 
         if ( strip == null )
         {
             while ( ( start != sz ) && Character.isWhitespace( str.charAt( start ) ) )
             {
                 start++;
             }
         }
         else
         {
             while ( ( start != sz ) && ( strip.indexOf( str.charAt( start ) ) != -1 ) )
             {
                 start++;
             }
         }
         return str.substring( start );
     }
 
     // Case conversion
     //--------------------------------------------------------------------------
 
     /**
      * <p>Convert a String to upper case, <code>null</code> String
      * returns <code>null</code>.</p>
      *
      * @param str the String to uppercase
      * @return the upper cased String
      */
     public static String upperCase( String str )
     {
         if ( str == null )
         {
             return null;
         }
         return str.toUpperCase();
     }
 
     /**
      * <p>Convert a String to lower case, <code>null</code> String
      * returns <code>null</code>.</p>
      *
      * @param str the string to lowercase
      * @return the lower cased String
      */
     public static String lowerCase( String str )
     {
         if ( str == null )
         {
             return null;
         }
         return str.toLowerCase();
     }
 
     /**
      * <p>Uncapitalise a String.</p>
      *
      * <p>That is, convert the first character into lower-case.
      * <code>null</code> is returned as <code>null</code>.</p>
      *
      * @param str the String to uncapitalise
      * @return uncapitalised String
      */
     public static String uncapitalise( String str )
     {
         if ( str == null )
         {
             return null;
         }
         else if ( str.length() == 0 )
         {
             return "";
         }
         else
         {
             return new StringBuffer( str.length() )
                 .append( Character.toLowerCase( str.charAt( 0 ) ) )
                 .append( str, 1, str.length() )
                 .toString();
         }
     }
 
     /**
      * <p>Capitalise a String.</p>
      *
      * <p>That is, convert the first character into title-case.
      * <code>null</code> is returned as <code>null</code>.</p>
      *
      * @param str the String to capitalise
      * @return capitalised String
      */
     public static String capitalise( String str )
     {
         if ( str == null )
         {
             return null;
         }
         else if ( str.length() == 0 )
         {
             return "";
         }
         else
         {
             return new StringBuilder( str.length() )
                 .append( Character.toTitleCase( str.charAt( 0 ) ) )
                 .append( str, 1, str.length() )
                 .toString();
         }
     }
 
     /**
      * <p>Swaps the case of String.</p>
      *
      * <p>Properly looks after making sure the start of words
      * are Titlecase and not Uppercase.</p>
      *
      * <p><code>null</code> is returned as <code>null</code>.</p>
      *
      * @param str the String to swap the case of
      * @return the modified String
      */
     public static String swapCase( String str )
     {
         if ( str == null )
         {
             return null;
         }
         int sz = str.length();
         StringBuilder buffer = new StringBuilder( sz );
 
         boolean whitespace = false;
         char ch;
         char tmp;
 
         for ( int i = 0; i < sz; i++ )
         {
             ch = str.charAt( i );
             if ( Character.isUpperCase( ch ) )
             {
                 tmp = Character.toLowerCase( ch );
             }
             else if ( Character.isTitleCase( ch ) )
             {
                 tmp = Character.toLowerCase( ch );
             }
             else if ( Character.isLowerCase( ch ) )
             {
                 if ( whitespace )
                 {
                     tmp = Character.toTitleCase( ch );
                 }
                 else
                 {
                     tmp = Character.toUpperCase( ch );
                 }
             }
             else
             {
                 tmp = ch;
             }
             buffer.append( tmp );
             whitespace = Character.isWhitespace( ch );
         }
         return buffer.toString();
     }
 
 
     /**
      * <p>Capitalise all the words in a String.</p>
      *
      * <p>Uses {@link Character#isWhitespace(char)} as a
      * separator between words.</p>
      *
      * <p><code>null</code> will return <code>null</code>.</p>
      *
      * @param str the String to capitalise
      * @return capitalised String
      */
     public static String capitaliseAllWords( String str )
     {
         if ( str == null )
         {
             return null;
         }
         int sz = str.length();
         StringBuilder buffer = new StringBuilder( sz );
         boolean space = true;
         for ( int i = 0; i < sz; i++ )
         {
             char ch = str.charAt( i );
             if ( Character.isWhitespace( ch ) )
             {
                 buffer.append( ch );
                 space = true;
             }
             else if ( space )
             {
                 buffer.append( Character.toTitleCase( ch ) );
                 space = false;
             }
             else
             {
                 buffer.append( ch );
             }
         }
         return buffer.toString();
     }
 
     /**
      * <p>Uncapitalise all the words in a string.</p>
      *
      * <p>Uses {@link Character#isWhitespace(char)} as a
      * separator between words.</p>
      *
      * <p><code>null</code> will return <code>null</code>.</p>
      *
      * @param str  the string to uncapitalise
      * @return uncapitalised string
      */
     public static String uncapitaliseAllWords( String str )
     {
         if ( str == null )
         {
             return null;
         }
         int sz = str.length();
         StringBuilder buffer = new StringBuilder( sz );
         boolean space = true;
         for ( int i = 0; i < sz; i++ )
         {
             char ch = str.charAt( i );
             if ( Character.isWhitespace( ch ) )
             {
                 buffer.append( ch );
                 space = true;
             }
             else if ( space )
             {
                 buffer.append( Character.toLowerCase( ch ) );
                 space = false;
             }
             else
             {
                 buffer.append( ch );
             }
         }
         return buffer.toString();
     }
 
     // Nested extraction
     //--------------------------------------------------------------------------
 
     /**
      * <p>Get the String that is nested in between two instances of the
      * same String.</p>
      *
      * <p>If <code>str</code> is <code>null</code>, will
      * return <code>null</code>.</p>
      *
      * @param str the String containing nested-string
      * @param tag the String before and after nested-string
      * @return the String that was nested, or <code>null</code>
      * @throws NullPointerException if tag is <code>null</code>
      */
     public static String getNestedString( String str, String tag )
     {
         return getNestedString( str, tag, tag );
     }
 
     /**
      * <p>Get the String that is nested in between two Strings.</p>
      *
      * @param str the String containing nested-string
      * @param open the String before nested-string
      * @param close the String after nested-string
      * @return the String that was nested, or <code>null</code>
      * @throws NullPointerException if open or close is <code>null</code>
      */
     public static String getNestedString( String str, String open, String close )
     {
         if ( str == null )
         {
             return null;
         }
         int start = str.indexOf( open );
         if ( start != -1 )
         {
             int end = str.indexOf( close, start + open.length() );
             if ( end != -1 )
             {
                 return str.substring( start + open.length(), end );
             }
         }
         return null;
     }
 
     /**
      * <p>How many times is the substring in the larger String.</p>
      *
      * <p><code>null</code> returns <code>0</code>.</p>
      *
      * @param str the String to check
      * @param sub the substring to count
      * @return the number of occurances, 0 if the String is <code>null</code>
      * @throws NullPointerException if sub is <code>null</code>
      */
     public static int countMatches( String str, String sub )
     {
         if ( sub.equals( "" ) )
         {
             return 0;
         }
         if ( str == null )
         {
             return 0;
         }
         int count = 0;
         int idx = 0;
         while ( ( idx = str.indexOf( sub, idx ) ) != -1 )
         {
             count++;
             idx += sub.length();
         }
         return count;
     }
 
     // Character Tests
     //--------------------------------------------------------------------------
 
     /**
      * <p>Checks if the String contains only unicode letters.</p>
      *
      * <p><code>null</code> will return <code>false</code>.
      * An empty String will return <code>true</code>.</p>
      *
      * @param str the String to check
      * @return <code>true</code> if only contains letters, and is non-null
      */
     public static boolean isAlpha( String str )
     {
         if ( str == null )
         {
             return false;
         }
         int sz = str.length();
         for ( int i = 0; i < sz; i++ )
         {
             if ( Character.isLetter( str.charAt( i ) ) == false )
             {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * <p>Checks if the String contains only whitespace.</p>
      *
      * <p><code>null</code> will return <code>false</code>. An
      * empty String will return <code>true</code>.</p>
      *
      * @param str the String to check
      * @return <code>true</code> if only contains whitespace, and is non-null
      */
     public static boolean isWhitespace( String str )
     {
         if ( str == null )
         {
             return false;
         }
         int sz = str.length();
         for ( int i = 0; i < sz; i++ )
         {
             if ( ( Character.isWhitespace( str.charAt( i ) ) == false ) )
             {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * <p>Checks if the String contains only unicode letters and
      * space (<code>' '</code>).</p>
      *
      * <p><code>null</code> will return <code>false</code>. An
      * empty String will return <code>true</code>.</p>
      *
      * @param str the String to check
      * @return <code>true</code> if only contains letters and space,
      *  and is non-null
      */
     public static boolean isAlphaSpace( String str )
     {
         if ( str == null )
         {
             return false;
         }
         int sz = str.length();
         for ( int i = 0; i < sz; i++ )
         {
             if ( ( Character.isLetter( str.charAt( i ) ) == false ) &&
                 ( str.charAt( i ) != ' ' ) )
             {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * <p>Checks if the String contains only unicode letters or digits.</p>
      *
      * <p><code>null</code> will return <code>false</code>. An empty
      * String will return <code>true</code>.</p>
      *
      * @param str the String to check
      * @return <code>true</code> if only contains letters or digits,
      *  and is non-null
      */
     public static boolean isAlphanumeric( String str )
     {
         if ( str == null )
         {
             return false;
         }
         int sz = str.length();
         for ( int i = 0; i < sz; i++ )
         {
             if ( Character.isLetterOrDigit( str.charAt( i ) ) == false )
             {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * <p>Checks if the String contains only unicode letters, digits
      * or space (<code>' '</code>).</p>
      *
      * <p><code>null</code> will return <code>false</code>. An empty
      * String will return <code>true</code>.</p>
      *
      * @param str the String to check
      * @return <code>true</code> if only contains letters, digits or space,
      *  and is non-null
      */
     public static boolean isAlphanumericSpace( String str )
     {
         if ( str == null )
         {
             return false;
         }
         int sz = str.length();
         for ( int i = 0; i < sz; i++ )
         {
             if ( ( Character.isLetterOrDigit( str.charAt( i ) ) == false ) &&
                 ( str.charAt( i ) != ' ' ) )
             {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * <p>Checks if the String contains only unicode digits.</p>
      *
      * <p><code>null</code> will return <code>false</code>.
      * An empty String will return <code>true</code>.</p>
      *
      * @param str the String to check
      * @return <code>true</code> if only contains digits, and is non-null
      */
     public static boolean isNumeric( String str )
     {
         if ( str == null )
         {
             return false;
         }
         int sz = str.length();
         for ( int i = 0; i < sz; i++ )
         {
             if ( Character.isDigit( str.charAt( i ) ) == false )
             {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * <p>Checks if the String contains only unicode digits or space
      * (<code>' '</code>).</p>
      *
      * <p><code>null</code> will return <code>false</code>. An empty
      * String will return <code>true</code>.</p>
      *
      * @param str the String to check
      * @return <code>true</code> if only contains digits or space,
      *  and is non-null
      */
     public static boolean isNumericSpace( String str )
     {
         if ( str == null )
         {
             return false;
         }
         int sz = str.length();
         for ( int i = 0; i < sz; i++ )
         {
             if ( ( Character.isDigit( str.charAt( i ) ) == false ) &&
                 ( str.charAt( i ) != ' ' ) )
             {
                 return false;
             }
         }
         return true;
     }
 
     // Defaults
     //--------------------------------------------------------------------------
 
     /**
      * <p>Returns either the passed in <code>Object</code> as a String,
      * or, if the <code>Object</code> is <code>null</code>, an empty
      * String.</p>
      *
      * @param obj the Object to check
      * @return the passed in Object's toString, or blank if it was
      *  <code>null</code>
      */
     public static String defaultString( Object obj )
     {
         return defaultString( obj, "" );
     }
 
     /**
      * <p>Returns either the passed in <code>Object</code> as a String,
      * or, if the <code>Object</code> is <code>null</code>, a passed
      * in default String.</p>
      *
      * @param obj the Object to check
      * @param defaultString  the default String to return if str is
      *  <code>null</code>
      * @return the passed in string, or the default if it was
      *  <code>null</code>
      */
     public static String defaultString( Object obj, String defaultString )
     {
         return ( obj == null ) ? defaultString : obj.toString();
     }
 
     // Reversing
     //--------------------------------------------------------------------------
 
     /**
      * <p>Reverse a String.</p>
      *
      * <p><code>null</code> String returns <code>null</code>.</p>
      *
      * @param str the String to reverse
      * @return the reversed String
      */
     public static String reverse( String str )
     {
         if ( str == null )
         {
             return null;
         }
         return new StringBuffer( str ).reverse().toString();
     }
 
     /**
      * <p>Reverses a String that is delimited by a specific character.</p>
      *
      * <p>The Strings between the delimiters are not reversed.
      * Thus java.lang.String becomes String.lang.java (if the delimiter
      * is <code>'.'</code>).</p>
      *
      * @param str the String to reverse
      * @param delimiter the delimiter to use
      * @return the reversed String
      */
     public static String reverseDelimitedString( String str, String delimiter )
     {
         // could implement manually, but simple way is to reuse other,
         // probably slower, methods.
         String[] strs = split( str, delimiter );
         reverseArray( strs );
         return join( strs, delimiter );
     }
 
     /**
      * <p>Reverses an array.</p>
      *
      * <p>TAKEN FROM CollectionsUtils.</p>
      *
      * @param array  the array to reverse
      */
     private static void reverseArray( Object[] array )
     {
         int i = 0;
         int j = array.length - 1;
         Object tmp;
 
         while ( j > i )
         {
             tmp = array[j];
             array[j] = array[i];
             array[i] = tmp;
             j--;
             i++;
         }
     }
 
     // Abbreviating
     //--------------------------------------------------------------------------
 
     /**
      * Turn "Now is the time for all good men" into "Now is the time for..."
      * <p>
      * Specifically:
      * <p>
      * If str is less than max characters long, return it.
      * Else abbreviate it to (substring(str, 0, max-3) + "...").
      * If maxWidth is less than 3, throw an IllegalArgumentException.
      * In no case will it return a string of length greater than maxWidth.
      *
      * @param maxWidth maximum length of result string
      **/
     public static String abbreviate( String s, int maxWidth )
     {
         return abbreviate( s, 0, maxWidth );
     }
 
     /**
      * Turn "Now is the time for all good men" into "...is the time for..."
      * <p>
      * Works like abbreviate(String, int), but allows you to specify a "left edge"
      * offset.  Note that this left edge is not necessarily going to be the leftmost
      * character in the result, or the first
      * character following the ellipses, but it will appear somewhere in the result.
      * In no case will it return a string of length greater than maxWidth.
      *
      * @param offset left edge of source string
      * @param maxWidth maximum length of result string
      **/
     public static String abbreviate( String s, int offset, int maxWidth )
     {
         if ( maxWidth < 4 )
         {
             throw new IllegalArgumentException( "Minimum abbreviation width is 4" );
         }
         if ( s.length() <= maxWidth )
         {
             return s;
         }
         if ( offset > s.length() )
         {
             offset = s.length();
         }
         if ( ( s.length() - offset ) < ( maxWidth - 3 ) )
         {
             offset = s.length() - ( maxWidth - 3 );
         }
         if ( offset <= 4 )
         {
             return s.substring( 0, maxWidth - 3 ) + "...";
         }
         if ( maxWidth < 7 )
         {
             throw new IllegalArgumentException( "Minimum abbreviation width with offset is 7" );
         }
         if ( ( offset + ( maxWidth - 3 ) ) < s.length() )
         {
             return "..." + abbreviate( s.substring( offset ), maxWidth - 3 );
         }
         return "..." + s.substring( s.length() - ( maxWidth - 3 ) );
     }
 
     // Difference
     //--------------------------------------------------------------------------
 
     /**
      * Compare two strings, and return the portion where they differ.
      * (More precisely, return the remainder of the second string,
      * starting from where it's different from the first.)
      * <p>
      * E.g. strdiff("i am a machine", "i am a robot") -&gt; "robot"
      *
      * @return the portion of s2 where it differs from s1; returns the empty string ("") if they are equal
      **/
     public static String difference( String s1, String s2 )
     {
         int at = differenceAt( s1, s2 );
         if ( at == -1 )
         {
             return "";
         }
         return s2.substring( at );
     }
 
     /**
      * Compare two strings, and return the index at which the strings begin to differ.
      * <p>
      * E.g. strdiff("i am a machine", "i am a robot") -&gt; 7
      * </p>
      *
      * @return the index where s2 and s1 begin to differ; -1 if they are equal
      **/
     public static int differenceAt( String s1, String s2 )
     {
         int i;
         for ( i = 0; ( i < s1.length() ) && ( i < s2.length() ); ++i )
         {
             if ( s1.charAt( i ) != s2.charAt( i ) )
             {
                 break;
             }
         }
         if ( ( i < s2.length() ) || ( i < s1.length() ) )
         {
             return i;
         }
         return -1;
     }
 
     public static String interpolate( String text, Map<?, ?> namespace )
     {
         Iterator<?> keys = namespace.keySet().iterator();
 
         while ( keys.hasNext() )
         {
             String key = keys.next().toString();
 
             Object obj = namespace.get( key );
 
             if ( obj == null )
             {
                 throw new NullPointerException( "The value of the key '" + key + "' is null." );
             }
 
             String value = obj.toString();
 
             text = replace( text, "${" + key + "}", value );
 
             if ( !key.contains( " " ) )
             {
                 text = replace( text, "$" + key, value );
             }
         }
         return text;
     }
 
     public static String removeAndHump( String data, String replaceThis )
     {
         String temp;
 
         StringBuilder out = new StringBuilder();
 
         temp = data;
 
         StringTokenizer st = new StringTokenizer( temp, replaceThis );
 
         while ( st.hasMoreTokens() )
         {
             String element = (String) st.nextElement();
 
             out.append( capitalizeFirstLetter( element ) );
         }
 
         return out.toString();
     }
 
     public static String capitalizeFirstLetter( String data )
     {
         char firstLetter = Character.toTitleCase( data.substring( 0, 1 ).charAt( 0 ) );
 
         String restLetters = data.substring( 1 );
 
         return firstLetter + restLetters;
     }
 
     public static String lowercaseFirstLetter( String data )
     {
         char firstLetter = Character.toLowerCase( data.substring( 0, 1 ).charAt( 0 ) );
 
         String restLetters = data.substring( 1 );
 
         return firstLetter + restLetters;
     }
 
     public static String addAndDeHump( String view )
     {
         StringBuilder sb = new StringBuilder();
 
         for ( int i = 0; i < view.length(); i++ )
         {
             if ( ( i != 0 ) && Character.isUpperCase( view.charAt( i ) ) )
             {
                 sb.append( '-' );
             }
 
             sb.append( view.charAt( i ) );
         }
 
         return sb.toString().trim().toLowerCase( Locale.ENGLISH );
     }
 
     /**
      * <p>Quote and escape a String with the given character, handling <code>null</code>.</p>
      *
      * <pre>
      * StringUtils.quoteAndEscape(null, *)    = null
      * StringUtils.quoteAndEscape("", *)      = ""
      * StringUtils.quoteAndEscape("abc", '"') = abc
      * StringUtils.quoteAndEscape("a\"bc", '"') = "a\"bc"
      * StringUtils.quoteAndEscape("a\"bc", '\'') = 'a\"bc'
      * </pre>
      *
      * @param source
      * @param quoteChar
      * @return the String quoted and escaped
      * @since 1.5.1
      * @see #quoteAndEscape(String, char, char[], char[], char, boolean)
      */
     public static String quoteAndEscape( String source,
                                 char quoteChar )
     {
         return quoteAndEscape( source, quoteChar, new char[]{ quoteChar }, new char[]{ ' ' }, '\\', false );
     }
 
     /**
      * <p>Quote and escape a String with the given character, handling <code>null</code>.</p>
      *
      * @param source
      * @param quoteChar
      * @param quotingTriggers
      * @return the String quoted and escaped
      * @since 1.5.1
      * @see #quoteAndEscape(String, char, char[], char[], char, boolean)
      */
     public static String quoteAndEscape( String source,
                                          char quoteChar,
                                          char[] quotingTriggers )
     {
         return quoteAndEscape( source, quoteChar, new char[]{ quoteChar }, quotingTriggers, '\\', false );
     }
 
     /**
      * @param source
      * @param quoteChar
      * @param escapedChars
      * @param escapeChar
      * @param force
      * @return the String quoted and escaped
      * @since 1.5.1
      * @see #quoteAndEscape(String, char, char[], char[], char, boolean)
      */
     public static String quoteAndEscape( String source,
                                 char quoteChar,
                                 final char[] escapedChars,
                                 char escapeChar,
                                 boolean force )
     {
         return quoteAndEscape( source, quoteChar, escapedChars, new char[]{ ' ' }, escapeChar, force );
     }
 
     /**
      * @param source
      * @param quoteChar
      * @param escapedChars
      * @param quotingTriggers
      * @param escapeChar
      * @param force
      * @return the String quoted and escaped
      * @since 1.5.1
      */
     public static String quoteAndEscape( String source,
                                 char quoteChar,
                                 final char[] escapedChars,
                                 final char[] quotingTriggers,
                                 char escapeChar,
                                 boolean force )
     {
         return quoteAndEscape(source, quoteChar, escapedChars, quotingTriggers, escapeChar + "%s", force);
     }
 
     /**
      * @param source
      * @param quoteChar
      * @param escapedChars
      * @param quotingTriggers
      * @param escapePattern
      * @param force
      * @return the String quoted and escaped
      * @since 3.0.4
      */
     public static String quoteAndEscape(String source,
                                         char quoteChar,
                                         final char[] escapedChars,
                                         final char[] quotingTriggers,
                                         String escapePattern,
                                         boolean force) {
         if ( source == null )
         {
             return null;
         }
 
         if ( !force && source.startsWith( Character.toString( quoteChar ) )
                 && source.endsWith( Character.toString( quoteChar ) ) )
         {
             return source;
         }
 
         String escaped = escape( source, escapedChars, escapePattern );
 
         boolean quote = false;
         if ( force )
         {
             quote = true;
         }
         else if ( !escaped.equals( source ) )
         {
             quote = true;
         }
         else
         {
             for ( char quotingTrigger : quotingTriggers )
             {
                 if ( escaped.indexOf( quotingTrigger ) > -1 )
                 {
                     quote = true;
                     break;
                 }
             }
         }
 
         if ( quote )
         {
             return quoteChar + escaped + quoteChar;
         }
 
         return escaped;
     }
 
     /**
      * @param source
      * @param escapedChars
      * @param escapeChar
      * @return the String escaped
      * @since 1.5.1
      */
     public static String escape( String source, final char[] escapedChars, char escapeChar )
     {
         return escape(source, escapedChars, escapeChar + "%s");
     }
 
     /**
      * @param source
      * @param escapedChars
      * @param escapePattern
      * @return the String escaped
      * @since 3.0.4
      */
     public static String escape( String source, final char[] escapedChars, String escapePattern )
     {
         if ( source == null )
         {
             return null;
         }
 
         char[] eqc = new char[ escapedChars.length ];
         System.arraycopy( escapedChars, 0, eqc, 0, escapedChars.length );
         Arrays.sort( eqc );
 
         StringBuilder buffer = new StringBuilder( source.length() );
 
         for ( int i = 0; i < source.length(); i++ )
         {
             final char c = source.charAt( i );
             int result = Arrays.binarySearch( eqc, c );
 
             if ( result > -1 )
             {
                 buffer.append( String.format(escapePattern, c) );
             }
             else
             {
                 buffer.append( c );
             }
         }
 
         return buffer.toString();
     }
 
     /**
      * Remove all duplicate whitespace characters and line terminators are replaced with a single
      * space.
      *
      * @param s a not null String
      * @return a string with unique whitespace.
      * @since 1.5.7
      */
     public static String removeDuplicateWhitespace( String s )
     {
         StringBuilder result = new StringBuilder( );
         int length = s.length();
         boolean isPreviousWhiteSpace = false;
         for (int i = 0; i < length; i++){
             char c = s.charAt( i );
             boolean thisCharWhiteSpace = Character.isWhitespace( c );
             if (!(isPreviousWhiteSpace && thisCharWhiteSpace)){
                 result.append( c );
             }
             isPreviousWhiteSpace = thisCharWhiteSpace;
         }
         return result.toString();
     }
 
     /**
      * Parses the given String and replaces all occurrences of
      * '\n', '\r' and '\r\n' with the system line separator.
      *
      * @param s a not null String
      * @return a String that contains only System line separators.
      * @see #unifyLineSeparators(String, String)
      * @since 1.5.7
      */
      public static String unifyLineSeparators( String s )
      {
          return unifyLineSeparators( s, System.getProperty( "line.separator" ) );
      }
 
     /**
      * Parses the given String and replaces all occurrences of
      * '\n', '\r' and '\r\n' with the system line separator.
      *
      * @param s a not null String
      * @param ls the wanted line separator ("\n" on UNIX), if null using the System line separator.
      * @return a String that contains only System line separators.
      * @throws IllegalArgumentException if ls is not '\n', '\r' and '\r\n' characters.
      * @since 1.5.7
      */
      public static String unifyLineSeparators( String s, String ls )
      {
         if ( s == null )
         {
             return null;
         }
 
         if ( ls == null )
         {
             ls = System.getProperty( "line.separator" );
         }
 
         if ( !( ls.equals( "\n" ) || ls.equals( "\r" ) || ls.equals( "\r\n" ) ) )
         {
             throw new IllegalArgumentException( "Requested line separator is invalid." );
         }
 
         int length = s.length();
 
         StringBuilder buffer = new StringBuilder( length );
         for ( int i = 0; i < length; i++ )
         {
             if ( s.charAt( i ) == '\r' )
             {
                 if ( ( i + 1 ) < length && s.charAt( i + 1 ) == '\n' )
                 {
                     i++;
                 }
 
                 buffer.append( ls );
             }
             else if ( s.charAt( i ) == '\n' )
             {
                 buffer.append( ls );
             }
             else
             {
                 buffer.append( s.charAt( i ) );
             }
         }
 
         return buffer.toString();
     }
 
     /**
      * <p>Checks if String contains a search character, handling <code>null</code>.
      * This method uses {@link String#indexOf(int)}.</p>
      *
      * <p>A <code>null</code> or empty ("") String will return <code>false</code>.</p>
      *
      * <pre>
      * StringUtils.contains(null, *)    = false
      * StringUtils.contains("", *)      = false
      * StringUtils.contains("abc", 'a') = true
      * StringUtils.contains("abc", 'z') = false
      * </pre>
      *
      * @param str  the String to check, may be null
      * @param searchChar  the character to find
      * @return true if the String contains the search character,
      *  false if not or <code>null</code> string input
      * @since 1.5.7
      */
     public static boolean contains( String str, char searchChar )
     {
         if ( isEmpty( str ) )
         {
             return false;
         }
         return str.indexOf( searchChar ) >= 0;
     }
 
     /**
      * <p>Checks if String contains a search String, handling <code>null</code>.
      * This method uses {@link String#indexOf(int)}.</p>
      *
      * <p>A <code>null</code> String will return <code>false</code>.</p>
      *
      * <pre>
      * StringUtils.contains(null, *)     = false
      * StringUtils.contains(*, null)     = false
      * StringUtils.contains("", "")      = true
      * StringUtils.contains("abc", "")   = true
      * StringUtils.contains("abc", "a")  = true
      * StringUtils.contains("abc", "z")  = false
      * </pre>
      *
      * @param str  the String to check, may be null
      * @param searchStr  the String to find, may be null
      * @return true if the String contains the search String,
      *  false if not or <code>null</code> string input
      * @since 1.5.7
      */
     public static boolean contains( String str, String searchStr )
     {
         if ( str == null || searchStr == null )
         {
             return false;
         }
         return str.contains( searchStr );
     }
 }