CODEWITHSUNDEEP
java
Marcus Becker
Marcus Becker

Reputation: 352

File.createTempFile check if file exists?

If I use this method, and by chance there is a temporary file with the same name, the file is overwritten? I'm talking about an application that will generate many temporary files, for a long time.

Upvotes: 3

Views: 5758

Answers (2)

Keerthivasan
Keerthivasan

Reputation: 12880

I'd suggest you to use a counter to create a new file name, if one already exists like this

File file = new File(filename);
for (int i = 0; file.exists(); i++) {
    file = new File(filename + i);
}
// write the file now

Hope it gives an idea!

Upvotes: 0

Elliott Frisch
Elliott Frisch

Reputation: 201437

From the JavaDoc on createTempFile (here) on the line labeled 2,

Neither this method nor any of its variants will return the same abstract pathname again in the current invocation of the virtual machine.

Edit

And the Returns section says

An abstract pathname denoting a newly-created empty file

And, it further states

Creates a new empty file in the specified directory, using the given prefix and suffix strings to generate its name. If this method returns successfully then it is guaranteed that: The file denoted by the returned abstract pathname did not exist before this method was invoked

Upvotes: 8

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