Java – regular expressions that begin with an underscore but do not contain any underscores

I try to get the name of the file from the last underscore until the end

For example, ABC_ AA. XML should be ABC and ABC_ AASD_ AD_ AA. XML should be ABC_ AASD_ AD

I'm considering using the non greedy exclusive ^ symbol I tried this:

String nameToSearch = testName.replaceAll("_(^(_).)+\\.xml$","");

Solution

How to use simple substrings instead of regular expressions

String nameToSearch = testName.substring(0,testName.lastIndexOf('_'));

Or if not_ You can use

String noSuffix = testName.substring(0,testName.lastIndexOf('.'));//remove ".xml" 
String nameToSearch  = noSuffix.substring(0,testName.lastIndexOf('_'));

But if you really want to use regular expressions, you can try them

testName.replaceAll("_[^_]*[.]xml$","");

It will match (and delete)_ Has zero or more non_ Character [^]* And with End of XML

If not_ You can use_ [^ _] * Optional

testName.replaceAll("(_[^_]*)?[.]xml$","");