Question

I wrote a regular expression that will replace odd number of slashes by an even number of slashes while leaves the even number of slashes intact. But for some reason I am getting an error:

int matchFlags   = StringUtil.MATCH_SINGLELINE;
int replaceFlags = StringUtil.REPLACE_ALL +  StringUtil.REPLACE_BACKREFERENCES;
String pattern = "(?<!/)/(//)*(?!/)"; //replace odd # of slashes only.
String replace = "$0$0";
RE re = new RE(pattern, matchFlags);
result= re.subst(result, replace, replaceFlags);

This is the exception:

Exception in thread "main" org.apache.regexp.RESyntaxException: Syntax error: Missing operand to closure

Answer 1

this works fine:

public class Test {
    public static void main(String[] args) {
        System.out.println(args[0].matches("(?<!/)/(//)*(?!/)"));
    }
}

maybe your RE expects something different