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Check if a path represents a file or a folder

java
file-system
path-api
file-operations
Anton ShumikhinbyAnton ShumikhinΒ·Sep 15, 2024
⚑TLDR

Determine the type of a Path (file or directory) with **Files.isDirectory(Path)** and Files.isRegularFile(Path):

import java.nio.file.*; Path path = Paths.get("your/path/here"); // Replace with your actual path if (Files.isDirectory(path)) { System.out.println("Congratulations! You've found a directory πŸ“"); } else if (Files.isRegularFile(path)) { System.out.println("Voila! It's a file πŸ“„"); } else { System.out.println("Oops! Neither a file nor a directory πŸ˜•"); }

To prevent any NullPointerException, ensure path is not null before running these checks.

Detecting non-existent paths

When a path is non-existent, Files.isDirectory(Path) and Files.isRegularFile(Path) return false. Here's how you handle this:

if (!Files.exists(path)) { System.out.println("I'm Sherlock, and even I can't find this path πŸ”"); } else { // Insert the checks from the fast answer here }

Also, a path might be a symbolic link or other collateral entities. Configure how symbolic links should be treated:

import java.nio.file.*; if (Files.isDirectory(path, LinkOption.NOFOLLOW_LINKS)) { // Look Ma, no symbolic link! We found a real directory 😎 } else if (Files.isRegularFile(path, LinkOption.NOFOLLOW_LINKS)) { // Eureka! It's a tangible file, not a symbolic link πŸ₯³ }

Deciding between the File and Path APIs

While java.io.File was the OG, it has shortcomings with handling symbolic links and file attributes. The new kid on the block, java.nio.file.Files, offers better compatibility across various platforms. So, prefer the shiny new Path and Files classes for efficient filesystem manipulation.

Tips and common pitfalls

Jedi code warriors handle their exceptions. Wrap your checks within a try-catch block to manage potential IOExceptions:

try { // Insert file/directory check logic here } catch (IOException ex) { System.out.println("IOException occurred. Did you try turning it off and on again? πŸ€“"); // Handle error gracefully }

And when you think you're smart enough to identify directories by the lack of an extension, remember:

  • Directories can be sly foxes and contain periods ('.') in their names.
  • Make your methods return a boolean to write a piece of script Bill Gates would be proud of!
  • Use clear application logic while determining what constitutes a 'file' or 'directory' - or you'll be forever stuck in the rabbit hole.