Question

I have below content in text file

  some texting content <img  src="cid:part123" alt=""> <b> Test</b>

I read it from file and store it in String i.e inputString

   expectedString = inputString.replaceAll("\\<img.*?cid:part123.*?>",
    "NewContent");

I get expected output i.e

     some texting content NewContent <b> Test</b>

Basically if there is end of line character in between img and src like below, it does not work for example below

 <img  
          src="cid:part123" alt="">

Is there a way regex ignore end of line character in between while matching?

Answer 1

If you want your dot (.) to match newline also, you can use Pattern.DOTALL flag. Alternativey, in case of String.replaceAll(), you can add a (?s) at the start of the pattern, which is equivalent to this flag.

From the Pattern.DOTALL – JavaDoc : –

Dotall mode can also be enabled via the embedded flag expression (?s).
(The s is a mnemonic for “single-line” mode, which is what this is
called in Perl.)

So, you can modify your pattern like this: –

expectedStr = inputString.replaceAll("(?s)<img.*?cid:part123.*?>", "Content");

NOTE: – You don’t need to escape your angular bracket(<).