Help regarding regular expression

Question

HI All ,
Please see the following string
String s = "IF ((NOT NUM4 IS ALPHABETIC ) AND NUM3 IS ALPHABETIC-UPPER AND (NUM5 IS GREATER OR EQUAL TO 3) AND (NUM5 IS NOT GREATER THAN 3) AND (NUM3 GREATER THAN 46) AND (NUM5 GREATER THAN NUM3) OR NUM3 LESS THAN 78) .";
My problem is: i want to capture the part of this line which contains "ALPHABETIC ,ALPHABETIC-UPPER for ex :NOT NUM4 IS ALPHABETIC , NUM3 IS ALPHABETIC-UPPER.from that I have to capture the word num4 , num3 which are in these phrases only ;from the whole string whereever it exists along with the phrase,Can any one help me out by suggesting something.num4 and num3 are variable names

Answer 1

I suspect you're right, Sabre, but I can't resist...
import java.util.regex.*;
* A rewriter does a global substitution in the strings passed to its
* 'rewrite' method. It uses the pattern supplied to its constructor, and is
* like 'String.replaceAll' except for the fact that its replacement strings
* are generated by invoking a method you write, rather than from another
* string. This class is supposed to be equivalent to Ruby's 'gsub' when given
* a block. This is the nicest syntax I've managed to come up with in Java so
* far. It's not too bad, and might actually be preferable if you want to do
* the same rewriting to a number of strings in the same method or class. See
* the example 'main' for a sample of how to use this class.
* @author Elliott Hughes
public abstract class Rewriter
  private Pattern pattern;
  private Matcher matcher;
   * Constructs a rewriter using the given regular expression; the syntax is
   * the same as for 'Pattern.compile'.
  public Rewriter(String regularExpression)
    this.pattern = Pattern.compile(regularExpression);
   * Returns the input subsequence captured by the given group during the
   * previous match operation.
  public String group(int i)
    return matcher.group(i);
   * Overridden to compute a replacement for each match. Use the method
   * 'group' to access the captured groups.
  public abstract String replacement();
   * Returns the result of rewriting 'original' by invoking the method
   * 'replacement' for each match of the regular expression supplied to the
   * constructor.
  public String rewrite(CharSequence original)
    this.matcher = pattern.matcher(original);
    StringBuffer result = new StringBuffer(original.length());
    while (matcher.find())
      matcher.appendReplacement(result, "");
      result.append(replacement());
    matcher.appendTail(result);
    return result.toString();
  public static void main(String[] args)
    String s = "IF ((NOT NUM4 IS ALPHABETIC ) " +
                "AND NUM3 IS ALPHABETIC-UPPER " +
                "AND (NUM5 IS GREATER  OR EQUAL TO 3) " +
                "AND (NUM5 IS NOT GREATER THAN 3) " +
                "AND (NUM3 GREATER THAN 46) " +
                "AND NUM645 IS ALPHABETIC " +
                "AND (NUM5 GREATER THAN NUM3) " +
                "OR NUM3 LESS THAN 78 " +
                "AND NUM34 IS ALPHABETIC-UPPER " +
                "AND NUM92 IS ALPHABETIC-LOWER " +
                "AND NUM0987 IS ALPHABETIC-LOWER) .";
    String result =
      new Rewriter("(NUM\\d+) +IS +(ALPHABETIC(?:-(?:UPPER|LOWER))?)")
        public String replacement()
          String type = group(2);
          if (type.endsWith("UPPER"))
            return "Character.isUpper(" + group(1) + ")";
          else if (type.endsWith("LOWER"))
            return "Character.isLower(" + group(1) + ")";
          else
            return "Character.isLetter(" + group(1) + ")";
      }.rewrite(s);
    System.out.println(result);
}