Question

I have data in the form:

<ol>
<li>example1</li>
<li>example2</li>
<li>example3</li>
</ol>

which needs to turn into

# example1
# example2
# example3

The pound sign has to be associated with the ol html tag. I’m using java regular expressions and this is what I have so far:

info = info.replaceAll("(?s).<ol>\n(<li>(.*?)</li>\n)*</ol>","# $2");

info is a string object containing the data. Also there may be line breaks in between the li tags.When I run it, it only prints the last item. i.e the result is

 # example3

example2 and example1 are missing

Any thoughts on what I’m doing wrong?

Answer 1

Your regex has a couple of problems:

• it contains a capturing group inside a capturing group
• overall, it will only match once (it includes for a start — there’s only one of these.

The solution I’d recommend: don’t tie yourself in knots. Write a loop with a Matcher.find(), pulling out the matches one by one and adding them to a string buffer. It would go something like this:

    Pattern p = Pattern.compile("<ol>(.*?)</ol>");
    Matcher m = p.matcher("...");
    StringBuffer sb = new StringBuffer();
    while (m.find()) {
        sb.append("#").append(m.group(1)).append("\n");
    }
    String result = sb.toString();