Question

I’ve got a problem finding empty HTML elements in a multiline HTML file. My regexp is this:

Pattern pattern = Pattern.compile("<([a-zA-Z][a-zA-Z0-9]*)[^>]*?>[\\s]*?</\\1>");
Matcher matcher = pattern.matcher(htmlOut);
while (matcher.find())
{
    htmlOut = matcher.replaceAll("");
    matcher = pattern.matcher(htmlOut);
}

The problem is it doesn’t match any of the empty tags.

FYI: The same regexp <([a-zA-Z][a-zA-Z0-9]*)[^>]*?>[\s]*?</\1> works in sublime text!

Any approach?

Answer 1

The pattern is OK, but you’re using it wrong. replaceAll() is called on the string, not on the matcher object.

Also, no need to iterate over the matches – one replaceAll is enough:

htmlOut = htmlOut.replaceAll("<([a-zA-Z][a-zA-Z0-9]*)[^>]*>\\s*</\\1>", "");

You don’t need lazy quantifiers, though – but that wouldn’t affect the match results.