How to use regex to match HTML tag contents in Java

Question

What I want to accomplish:

I want to match certain explicit content outside of comments.

An Example:

<div>
    <div>Hello $world$</div>
    <div>Another text <!-- $example$--></div>   
</div>
<div>
    How are $you$?
</div>
<!-- 
<div>
    Lorem ipsum $dolor$ sit
</div>
-->

Words I want to match: $world$ , $you$

Words I don't want to match: $example$ , $dolor$

So far I was only able to match either all or none.

What I can't do:

I can't delete all comments because because it's required to provide the source code I filtered.

can you specify the Regular expression you used, but didn't provide the results you hoped for? — blkpingu, May 04 '18 at 12:34
Finally I ended with this: `/(?:)($.*?$)/gsm` but it definitely not match what i want to match :) — Jan Nowak, May 04 '18 at 12:36
Add alternation (`/(?:)|($.*?$)/gsm`, notice the `|` in the middle) and check if there is anything in the first capturing group — Dmitry Egorov, May 04 '18 at 12:38
@DmitryEgorov It did the trick! Thank you. Can you please post your comment as an answer so thanks to that i'll be able to mark my question as resolved. — Jan Nowak, May 04 '18 at 12:42
@JanNowak feel free to read up on [what to do when someone answers my question](https://stackoverflow.com/help/someone-answers). — blkpingu, May 11 '18 at 17:50

score 0 · Answer 1 · answered May 04 '18 at 12:43

I can't tell where you come from with your code, but you need to read your page into a String oder String[] and then run a regular expression over it to extract the Strings you want to filter.

How to use a stream with regex in java:

How do I create a Stream of regex matches?

How to use regex in java:

https://www.tutorialspoint.com/java/java_regular_expressions.htm

Test your regular expression before deploying it:

https://regexr.com/

score 0 · Accepted Answer · answered May 04 '18 at 12:45

0

Add alternation

/(?:<!--.*?-->)|($.*?$)/gsm
               ^

and check if there is anything in the first capturing group.

answered May 04 '18 at 12:45

Dmitry Egorov

9,542
3
22
40

It’s probably a good idea to escape the `$`, especially the second one. – VGR May 04 '18 at 14:05

How to use regex to match HTML tag contents in Java

2 Answers2