Regex to validate file path with leading double backslash in Java

Question

I have a file path as below: \\ppk-ccr-02-llp\MOP_CIP\CO_PROJECT\alpha\stage\GOOGLE.COM_PROJECTS\bolt_cyclic_84\mango_test\8267

i want a regex to validate this in such a way that it checks

1. the string always starts with double backslash
2. followed by alpha numeric
3. rest of the single backslash is always surrounded with alpha numeric
4. it only allows _. \ - as special characters

Answer 1

The following expression \\\\([-.\w]+\\)*[-.\w]+ should work as shown in the demo:

• \\\\([-.\w]+\\)*[-.\w]+ - starting with \\
• ([-.\w]+\\)* - followed by 0 or else non-empty "words" consisting of alphanumerics, . , - and ending with \
• [-.\w]+ - entire string ending with non-empty "word"

In Java code, the backslashes are additionally escaped, so the path is validated as:

String fullPath = "\\\\ppk-ccr-02-llp\\MOP_CIP\\CO_PROJECT\\alpha\\stage\\GOOGLE.COM_PROJECTS\\bolt_cyclic_84\\mango_test\\8267";

if (fullPath.matches("\\\\\\\\([-.\\w]+\\\\)*[-.\\w]+")) {
}