Question

I have a String that looks like this

String = "Förpackning Flaska (375 ml) Förslutning Skruvkapsyl Kr/lit (104,00) Pris 39,00 kr Antal i butik 30 st Hyllplats 04-11-01 Förpackning Flaska (750 ml) Förslutning Plastkork/syntetkork Kr/lit (100,00) Pris 75,00 kr Antal i butik 16 st Hyllplats 02-03-01";

I want to extract some of the text inside this string.
The end result I want is this:

“Förpackning Flaska (375 ml) Antal i butik 30 st Förpackning Flaska (750 ml) Antal i butik 16 st”.

I can use the following code:

    name = name.replace(name.substring(name.indexOf(") ") + 2, name.indexOf("Antal")), "");
    name = name.replace(name.substring(name.indexOf("st ") + 2, name.lastIndexOf("")), "");

That will give me this result:

“Förpackning Flaska (375 ml) Antal i butik 30 st”

It basically does what I want it to do, but it stops after the first occurance of the pattern.

I have tried to use a regex pattern but I can’t get it to work. From observing the string, I have concluded that I need a regex pattern that matches everything between “) ” and “Antal”. I will also need to remove the other clutter, but that is easy. My problem is that I can’t seem to get my regex to work, and that would probably be the best way to do something like this. I know that I have to escape the paranthesis to make it a literal character in my regex, but I just can’t get it to work.

This is the regex I’ve come up with and tried:

    Pattern p = Pattern.compile("\b\\) (.+?)\bAntal");
    Matcher m = p.matcher(name);
    m.find();
    System.out.println(m.group(1));

Any help and ideas are welcome!

Answer 1

This can be done in one line!

It looks like you want to remove:

• the next two words after the word "st", and
• everything between ")" and "Antal"

Here’s the code that will do that:

input.replaceAll("((?<= st)( [^ ]+){2}|(?<=\\)).*?(?= Antal))", "");

Notes regarding the regex:

• I noticed you coded a word boundary as "\b". This is a mistake – you cded a literal backspace. Instead, you code it as "\\b"
• I’ve used a regex OR expression (A|B) to match both in one regex
• Both regexes use a look-behind to make the replacement text a blank, which is cleaner than matching part of the input you want to keep, then putting it back, and it meant I coudl combine both regexes into one OR expression
• the ? in ".*?" is important – it means a non-greedy match. Without it, it will match the first bracket and the last Antal, skipping over any Antal between

Here’s some test code:

public static void main(String[] args) {
    String input = "Förpackning Flaska (375 ml) Förslutning Skruvkapsyl Kr/lit (104,00) Pris 39,00 kr Antal i butik 30 st Hyllplats 04-11-01 Förpackning Flaska (750 ml) Förslutning Plastkork/syntetkork Kr/lit (100,00) Pris 75,00 kr Antal i butik 16 st Hyllplats 02-03-01";
    String clean = input.replaceAll("((?<= st)( [^ ]+){2}|(?<=\\)).*?(?= Antal))", "");
    System.out.println(clean);
}

Output:

Förpackning Flaska (375 ml) Antal i butik 30 st Förpackning Flaska (750 ml) Antal i butik 16 st