File.exists() returns false when file exists

user_37257 0
Viewed 110589

I've encountered a bug I can't seem to find any logic behind. I have this File object, which is created like this:

File file = new File("utilities/data/someTextFile.txt");

I then do file.exists(), and it returns false (!?). If the file is not found, I'm logging f.getAbsolutePath() to a file. When I look at the path, it seems OK. I can copy-paste the complete path into the "Run"-window in Windows and the file opens fine.

The file exists at all times and is not deleted nor changed during the running of my application. It is located at the local machine.

This only seems to occur in certain situations. I can reproduce the fault at any time, but I'm sure the path of the file object is not changed by the actions I make to reproduce the fault.

What can cause file.exists() to return false? Does this have something to do with permissions or file locks, etc.?

file-io java
17 Answers

If the process does not have permissions to tell whether a file exists it will return false. It may be possible to open a file, but not tell by normal methods if it exists.

Tom_Hawtin_-_tackline_47250

When ["Hide extensions for known file types."] is checked windows open "t.txt.txt" when type "t.txt" in [explorer]/[run windows] but programmatically not.

user_5702140

To generalize the issue the problem arises while converting URL/URI to local paths.

Example: URL url = file:/D:/code%20repo%20sample/sample.txt

// To remove url reference
String localPath = url.getPath();  
> /D:/code%20repo%20sample/sample.txt

// Decoding reserved characters in url from hexadecimal to character
URLDecoder.decode(localPath, StandardCharsets.UTF_8.toString()); 
> /D:/code repo sample/sample.txt

Hope this helps.

user_96108930

In my case

file save in

filepath = Environment.getExternalStorageDirectory().getAbsolutePath()+ "/VRSI/Audio/"+encrypted_filename+".mp3";

It is stored in in

/storage/emulated/0/VRSI/Audio/82B0999F16251F0DFE849F380D6AAEEA.mp3

it when when I get the file path is

/storage/emulated/0/Android/data/com.numerotec.vrsi/files/VRSI/Audio/AF7DC6C0C0B3EF3529EC70DAEF2324E0.mp3

So I replace the the string "Android/data/com.numerotec.vrsi/files/" as empty

after that

if (file.getAbsoluteFile().exists())
{
    // write your code
}

is working fine

user_118281640

If the situations where it fails involves running it as another user, and you're on Windows Vista/Windows 7, it could be caused by VirtualStore, the mechanism where Windows let an unprivileged user "write" places it normally cannot. The changes are however stored in "%USERPROFILE%\AppData\Local\VirtualStore\" which are private to each user account.

user_623710

When nothing from above worked for me, I tried 

filePath = filePath.trim();

This will clean your string from any unwanted charachter

user_99303370

FWIW, there is another place that this happens.

File("") is the name of the current directory. File("").exists() will usually return false. The File(("").getAbsoluteFile().exists() trick works and will return true (presuming the current directory exists...)

user_9452260

I lately came across this same issue. What l did was to uninstall Netbeans, deleted netbeans folder from C drive, program files, update, programData, virtually everywhere. Then reinstall. Is now working fine. Don't forget to backup up netbeans project folder before taken the actions above.

Hope it helps.

user_122049040

With some IDE(may be) and or with some OS(ex: window), by default they don't have write access on files. So if you try to do file.exists() it will show you false. in order to fix this, do like below

if your ref variable for File is f, example: File f = new File("path");

so in order to make it work , select f by mouse and then go to Search menu > Write access>Workspace. Hopefully it will work.

user_134866020
Related