Class Regsub

java.lang.Object
sunlabs.brazil.util.regexp.Regsub

public class Regsub extends Object
The Regsub class provides an iterator-like object to extract the matched and unmatched portions of a string with respect to a given regular expression.

After each match is found, the portions of the string already checked are not searched again -- searching for the next match will begin at the character just after where the last match ended.

Here is an example of using Regsub to replace all "%XX" sequences in a string with the ASCII character represented by the hex digits "XX":

 public static void
 main(String[] args)
     throws Exception
 {
     Regexp re = new Regexp("%[a-fA-F0-9][a-fA-F0-9]");
     Regsub rs = new Regsub(re, args[0]);

     StringBuffer sb = new StringBuffer();

     while (rs.nextMatch()) {
         sb.append(rs.skipped());

         String match = rs.matched();

         int hi = Character.digit(match.charAt(1), 16);
         int lo = Character.digit(match.charAt(2), 16);
         sb.append((char) ((hi << 4) | lo));
     }
     sb.append(rs.rest());

     System.out.println(sb);
 }
 
Version:
2.3
Author:
Colin Stevens (colin.stevens@sun.com)
See Also:
  • Constructor Summary

    Constructors
    Constructor
    Description
    Regsub(Regexp r, String str)
    Construct a new Regsub that can be used to step through the given string, finding each substring that matches the given regular expression.
  • Method Summary

    Modifier and Type
    Method
    Description
    Return the regexp used by this regsub.
    Returns a substring consisting of the characters that matched the entire regular expression during the last call to nextMatch.
    boolean
    Searches for the next substring that matches the regular expression.
    Returns a substring consisting of all the characters that come after the last match.
    Returns a substring consisting of all the characters skipped between the end of the last match (or the start of the original search string) and the start of this match.
    submatch(int i)
    Returns a substring consisting of the characters that matched the given parenthesized subexpression during the last call to nextMatch.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

  • Method Details

    • nextMatch

      public boolean nextMatch()
      Searches for the next substring that matches the regular expression. After calling this method, the caller would call methods like skipped, matched, etc. to query attributes of the matched region.

      Calling this function again will search for the next match, beginning at the character just after where the last match ended.

      Returns:
      true if a match was found, false if there are no more matches.
    • skipped

      public String skipped()
      Returns a substring consisting of all the characters skipped between the end of the last match (or the start of the original search string) and the start of this match.

      This method can be used extract all the portions of string that didn't match the regular expression.

      Returns:
      The characters that didn't match.
    • matched

      public String matched()
      Returns a substring consisting of the characters that matched the entire regular expression during the last call to nextMatch.
      Returns:
      The characters that did match.
      See Also:
    • submatch

      public String submatch(int i)
      Returns a substring consisting of the characters that matched the given parenthesized subexpression during the last call to nextMatch.
      Parameters:
      i - The index of the parenthesized subexpression.
      Returns:
      The characters that matched the subexpression, or null if the given subexpression did not exist or did not match.
    • rest

      public String rest()
      Returns a substring consisting of all the characters that come after the last match. As the matches progress, the rest gets shorter. When nextMatch returns false, then this method will return the rest of the string that can't be matched.
      Returns:
      The rest of the characters after the last match.
    • getRegexp

      public Regexp getRegexp()
      Return the regexp used by this regsub.