Substitute sub-strings in side of a string : Substring « Data Type « Java Tutorial






import java.util.Map;


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  * published by the Free Software Foundation; either version 2.1 of
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  *
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  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * Lesser General Public License for more details.
  *
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  * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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  */



public class Main{
  /** An empty string constant */
  public static final String EMPTY = "";

  /////////////////////////////////////////////////////////////////////////
  //                         Substitution Methods                        //
  /////////////////////////////////////////////////////////////////////////

  /**
   * Substitute sub-strings in side of a string.
   *
   * @param buff    Stirng buffer to use for substitution (buffer is not reset)
   * @param from    String to substitute from
   * @param to      String to substitute to
   * @param string  String to look for from in
   * @return        Substituted string
   */
  public static String subst(final StringBuffer buff, final String from,
     final String to, final String string)
  {
     int begin = 0, end = 0;

     while ((end = string.indexOf(from, end)) != -1)
     {
        // append the first part of the string
        buff.append(string.substring(begin, end));

        // append the replaced string
        buff.append(to);

        // update positions
        begin = end + from.length();
        end = begin;
     }

     // append the rest of the string
     buff.append(string.substring(begin, string.length()));

     return buff.toString();
  }

  /**
   * Substitute sub-strings in side of a string.
   *
   * @param from    String to substitute from
   * @param to      String to substitute to
   * @param string  String to look for from in
   * @return        Substituted string
   */
  public static String subst(final String from, final String to,
     final String string)
  {
     return subst(new StringBuffer(), from, to, string);
  }

  /**
   * Substitute sub-strings in side of a string.
   *
   * @param buff       String buffer to use for substitution (buffer is not reset)
   * @param string     String to subst mappings in
   * @param map        Map of from->to strings
   * @param beginToken Beginning token
   * @param endToken   Ending token
   * @return           Substituted string
   */
  public static String subst(final StringBuffer buff, final String string,
     final Map map, final String beginToken,
     final String endToken)
  {
     int begin = 0, rangeEnd = 0;
     Range range;

     while ((range = rangeOf(beginToken, endToken, string, rangeEnd)) != null)
     {
        // append the first part of the string
        buff.append(string.substring(begin, range.begin));

        // Get the string to replace from the map
        String key = string.substring(range.begin + beginToken.length(),
           range.end);
        Object value = map.get(key);
        // if mapping does not exist then use empty;
        if (value == null) value = EMPTY;

        // append the replaced string
        buff.append(value);

        // update positions
        begin = range.end + endToken.length();
        rangeEnd = begin;
     }

     // append the rest of the string
     buff.append(string.substring(begin, string.length()));

     return buff.toString();
  }

  /**
   * Substitute sub-strings in side of a string.
   *
   * @param string     String to subst mappings in
   * @param map        Map of from->to strings
   * @param beginToken Beginning token
   * @param endToken   Ending token
   * @return           Substituted string
   */
  public static String subst(final String string, final Map map,
     final String beginToken, final String endToken)
  {
     return subst(new StringBuffer(), string, map, beginToken, endToken);
  }

  /**
   * Substitute index identifiers with the replacement value from the
   * given array for the corresponding index.
   *
   * @param buff       The string buffer used for the substitution
   *                   (buffer is not reset).
   * @param string     String substitution format.
   * @param replace    Array of strings whose values will be used as 
   *                   replacements in the given string when a token with
   *                   their index is found.
   * @param token      The character token to specify the start of an index
   *                   reference.
   * @return           Substituted string.
   */
  public static String subst(final StringBuffer buff, final String string,
     final String replace[], final char token)
  {
     int i = string.length();
     for (int j = 0; j >= 0 && j < i; j++)
     {
        char c = string.charAt(j);

        // if the char is the token, then get the index
        if (c == token)
        {

           // if we aren't at the end of the string, get the index
           if (j != i)
           {
              int k = Character.digit(string.charAt(j + 1), 10);

              if (k == -1)
              {
                 buff.append(string.charAt(j + 1));
              }
              else if (k < replace.length)
              {
                 buff.append(replace[k]);
              }

              j++;
           }
        }
        else
        {
           buff.append(c);
        }
     }

     return buff.toString();
  }

  /**
   * Substitute index identifiers with the replacement value from the
   * given array for the corresponding index.
   *
   * @param string     String substitution format.
   * @param replace    Array of strings whose values will be used as 
   *                   replacements in the given string when a token with
   *                   their index is found.
   * @param token      The character token to specify the start of an index
   *                   reference.
   * @return           Substituted string.
   */
  public static String subst(final String string, final String replace[],
     final char token)
  {
     return subst(new StringBuffer(), string, replace, token);
  }

  /**
   * Substitute index identifiers (with <code>%</code> for the index token)
   * with the replacement value from the given array for the corresponding
   * index.
   *
   * @param string     String substitution format.
   * @param replace    Array of strings whose values will be used as 
   *                   replacements in the given string when a token with
   *                   their index is found.
   * @return           Substituted string.
   */
  public static String subst(final String string, final String replace[])
  {
     return subst(new StringBuffer(), string, replace, '%');
  }

  /////////////////////////////////////////////////////////////////////////
  //                             Range Methods                           //
  /////////////////////////////////////////////////////////////////////////

  /**
   * Represents a range between two integers.
   */
  public static class Range
  {
     /** The beginning of the range. */
     public int begin;

     /** The end of the range. */
     public int end;

     /**
      * Construct a new range.
      *
      * @param begin   The beginning of the range.
      * @param end     The end of the range.
      */
     public Range(int begin, int end)
     {
        this.begin = begin;
        this.end = end;
     }

     /**
      * Default constructor.
      */
     public Range()
     {
     }
  }

  /**
   * Return the range from a begining token to an ending token.
   *
   * @param beginToken String to indicate begining of range.
   * @param endToken   String to indicate ending of range.
   * @param string     String to look for range in.
   * @param fromIndex  Beginning index.
   * @return           (begin index, end index) or <i>null</i>.
   */
  public static Range rangeOf(final String beginToken, final String endToken,
     final String string, final int fromIndex)
  {
     int begin = string.indexOf(beginToken, fromIndex);

     if (begin != -1)
     {
        int end = string.indexOf(endToken, begin + 1);
        if (end != -1)
        {
           return new Range(begin, end);
        }
     }

     return null;
  }

  /**
   * Return the range from a begining token to an ending token.
   *
   * @param beginToken String to indicate begining of range.
   * @param endToken   String to indicate ending of range.
   * @param string     String to look for range in.
   * @return           (begin index, end index) or <i>null</i>.
   */
  public static Range rangeOf(final String beginToken, final String endToken,
     final String string)
  {
     return rangeOf(beginToken, endToken, string, 0);
  }

}








2.34.Substring
2.34.1.Get the difference between two strings
2.34.2.Gets a substring from the specified String avoiding exceptions.
2.34.3.Gets len characters from the middle of a String.
2.34.4.Gets the String that is nested in between two Strings. Only the first match is returned.
2.34.5.Gets the String that is nested in between two instances of the same String.
2.34.6.Gets the leftmost len characters of a String
2.34.7.Gets the rightmost len characters of a String.
2.34.8.Gets the substring after the first occurrence of a separator. The separator is not returned.
2.34.9.Gets the substring before the last occurrence of a separator. The separator is not returned.
2.34.10.Removes a substring only if it is at the begining of a source string, otherwise returns the source string.
2.34.11.Removes a substring only if it is at the end of a source string, otherwise returns the source string.
2.34.12.Substitute sub-strings in side of a string
2.34.13.Searches a String for substrings delimited by a start and end tag, returning all matching substrings in an array.
2.34.14.Counts how many times the substring appears in the larger String.
2.34.15.Count the number of instances of substring within a string