CODEWITHSUNDEEP
javaregex
JDiPierro
JDiPierro

Reputation: 802

Can't get regex to match in Java

I'm trying to match just the file extension on a URL to an image.. I've got this regex:

(?<=\.)(jpe?g|png|gif|bmp|tga|tiff)$

I've tested this on several websites and it matches just fine.. but when I try to use it in Java I added an extra \ to escape the . and I don't think I should have to add more than that? but this isn't working:

Pattern extensionPat = Pattern.compile("(?<=\\.)(jpe?g|png|gif|bmp|tga|tiff)$", Pattern.CASE_INSENSITIVE);
    Matcher findExtension = extensionPat.matcher(imageURL);
    String extension = findExtension.group();

where imageURL is "https://www.google.com/images/srpr/logo4w.png"

At a coworker's recommendation I tried escaping the pipes as well into:

Pattern extensionPat = Pattern.compile("(?<=\\.)(jpe?g\\|png\\|gif\\|bmp\\|tga\\|tiff)$", Pattern.CASE_INSENSITIVE);

I've tried escaping the $, and the <, and nothing seems to work...

Upvotes: 0

Views: 81

Answers (1)

Keppil
Keppil

Reputation: 46239

You need to call findExtension.find() first, otherwise findExtension.group() returns nothing.

Upvotes: 3

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