Is there a way in Java to determine if a path is valid without attempting to create a file?

java validation filesystems
Raibaz picture Raibaz · Jan 22, 2009 · Viewed 95k times · Source

I need to determine if a user-supplied string is a valid file path (i.e., if createNewFile() will succeed or throw an Exception) but I don't want to bloat the file system with useless files, created just for validation purposes.

Is there a way to determine if the string I have is a valid file path without attempting to create the file?

I know the definition of "valid file path" varies depending on the OS, but I was wondering if there was any quick way of accepting C:/foo or /foo and rejecting banana.

A possible approach may be attempting to create the file and eventually deleting it if the creation succeeded, but I hope there is a more elegant way of achieving the same result.

Answer

krosenvold picture krosenvold · Jan 22, 2009

This would check for the existance of the directory as well.

File file = new File("c:\\cygwin\\cygwin.bat");
if (!file.isDirectory())
   file = file.getParentFile();
if (file.exists()){
    ...
}

It seems like file.canWrite() does not give you a clear indication if you have permissions to write to the directory.

Related questions

How can I check if a single character appears in a string?

In Java is there a way to check the condition: "Does this single character appear at all in string x" without using a loop?

Read More
What is the best Java email address validation method?

What are the good email address validation libraries for Java? Are there any alternatives to commons validator?

Read More
Validating input using java.util.Scanner

I'm taking user input from System.in using a java.util.Scanner. I need to validate the input for things like: It must be a non-negative number It must be an alphabetical letter ... etc What's the best way to do …

Read More