Matching certain strings against patterns like:
[A-Z]{1,127}@[A-Z]{1,127}

hangs java.exe
eg match using string:
AAAAA

Tested as follows:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import org.apache.regexp.RE;

public class testIt
{
	public static void main(String[] args) throws Exception
	{
		BufferedReader console = new BufferedReader(
						new InputStreamReader
(System.in));     
		
		System.out.println("RE Pattern?: ");
		String input = console.readLine();
		
		RE r = new RE(input);
		while (true)
		{
			System.out.println("test against?: ");
			String test = console.readLine();
			System.out.println("Pattern is: " + test);
			
			boolean matched = r.match(test);
			System.out.println("MATCHED="+matched);
			
			String wholeExpr = r.getParen(0);
			System.out.println("wholeExpr IS: "+ wholeExpr);
		}
	}
}


RE Pattern:
([A-Z]{1,127}@[A-Z]{1,127})

Hangs java.exe when matched against:
AAAAA

Darrell.