regex - Java regexp for file filtering

Question

I would like to build a regexp in Java that would be passed in a FilenameFilter to filter the files in a dir.

The problem is that I can't get the hang of the regexp "mind model" :)

This is the regexp that I came up with to select the files that I would like to exclude

((ABC|XYZ))+w*Test.xml

What I would like to do is to select all the files that end with Test.xml but do not start with ABC or XYZ.

Could you please add any resources that could help me in my battle with regexps.

Thanks

The following resource explains a lot of things about regexp regular-expressions.info

Answer 1

This stuff is easier, faster and more readable without regexes.

if (str.endsWith("Test.xml") && !str.startsWith("ABC"))