Extract Drive Letter, java regex

Question

I cannot get this simple regex to work. I need to check to see if the file path includes the drive letter, if it doesn't throw an exception. ``` if (!arcvalFileFormBean.getTxtFileReview().matches("^([A-Z]):")) { status = "MAPPING ERROR: Please submit a file from a mapped drive (i.e. K:\)."; request.setAttribute(FairValConstants.status, status); throw new InvalidFileMoveException(FairValConstants.MAKE_VALID_SELECTION); } ``` When I test the code with this `W:	estFolder	estfile_v1234_12_23_2014_1245.pfd` it fails, when it should pass. When I test it without the drive letter, but the full path it fails. There is something wrong with my regex. I have tried a few different regexs but nothing has worked. Thanks for your time.

Accepted Answer

Problem is `matches("^([A-Z]):"))` since `String#matches` matched full input not just a part of it.

Try this instead to make it match full line:

```
if (!arcvalFileFormBean.getTxtFileReview().matches("((?i)(?s)[A-Z]):.*")) {
```

PS: `^` and `$` anchors are also not required in `String#matches` since that is implicit.

- `(?i)` => Ignore case

- `(?s)` => DOTALL (mase DOT match new lines as well)

Extract Drive Letter, java regex

Solution

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