The specified document name is not a valid file name. File names should not contain the following characters:

  • Asterisk ( * )
  • Vertical bar ( | )
  • Colon ( :
  • Double quotes ( " ).
  • Less ( < )
  • More ( > )
  • Question mark ( ? )
  • Slash ( / )
  • I will check backslash ( \ ) as a directory existence.

Please help to create a regular expression to check the occurrence of the above characters in a string (the path from disk to folder), can anyone have a ready-made solution, such an example? I need to check the correctness of the path entered (Checking the existence of the directory does not fit because it throws an exception if you enter an invalid character).

It is necessary to catch all invalid characters when the user enters the path. For example, if I check the path to the existence of directories, I will get an exception because of an invalid character, so I need to catch all the invalid characters. And it is not clear if I will throw an exception if I enter this path C:\folder\fol:der , for the characters < , > and others I received exceptions. You need to be sure that no matter what path the user enters, the program will not shut down and will catch the error and continue entering the path.

I check the path like this:

 Path Path; if (Files.exists(Path)) out.println(" Путь введён\n"); else out.println(" Ошибка");

If the variable contains an invalid character, then an exception is thrown:

Exception in thread "main" java.nio.file.InvalidPathException: Illegal char <? > at index 0:? Exception in thread "main" java.nio.file.InvalidPathException: Illegal char <<> at index 0: <

  • Google to help: regex match windows filename . - GreyGoblin
  • @GreyGoblin Answer the question by clicking on the appropriate button;) - aaa
  • one
    It is not clear how you want to exclude backslash from valid characters if this is a win path delimiter. Give the question, examples of incorrect, according to your logic, the path and the right way. now the question is incomprehensible and, it seems to me, the minuses are put for this reason - while1pass
  • @ while1pass I corrected, you are right. I check backward as a directory existence. - aaa
  • and still not clear what you want, give examples. the colon also goes into the path of the win-systems. for example, C: \ multitran \ PUH \ history.txt - while1pass

3 answers 3

I can assume that something like this:

 [az]:([\\/]?([^*|\\/:"<>]*))*
  • Something? Will it work? Somehow unsure :) - aaa
  • @ELe should work, but I didn’t check it :) - Qwertiy ♦
  • Readme.txt , Test\Readme.txt , Test\Readme.txt , \\Server\Test\Readme.txt - Anton Shchyrov
  • @AntonShchyrov What is it? - aaa
  • @AntonShchyrov, asked to check the full path. UNC - yes, did not count on him. But for normal paths, the file should work. - Qwertiy ♦

If we are talking only about the file name , then so

 [^\*\|\\\:\"<>\?\/]

If you need to check the full path, then everything is not so simple

  • Thanks, but you need to check the full path. - aaa

Entering invalid characters and missing directory caught as follows:

 String WAY; public void WAY() { do { out.print(" Vvedite adres programm\n"); boolean WHILE = true; out.print(" "); Scanner in = new Scanner(System.in); WAY = in.next(); try { Path PATH = Paths.get(WAY); if(Files.exists(PATH)) { out.print(" Adres programm vvedon\n"); WHILE = false; } else out.print(" Oshibka\n"); } catch (InvalidPathException e) { out.print(" Oshibka\n"); } } while(WHILE); }
  • one
    Where are the regular expressions that you requested to solve this problem? ) - Kromster
  • @Kromster Where have you been before? ) - aaa