CODEWITHSUNDEEP
javaandroidfilesimpledateformat
maskama
maskama

Reputation: 1

SimpleDateFormat doesn't work to createTempFile

I'm creating New TmepFile ,and want to make format "yyyyMMdd" but it's work until createTempFile .

private File createFile() throws IOException{
        String tempName = new SimpleDateFormat("yyyyMMdd").format(new Date());
        File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
        Log.d("e",tempName);

        File image = File.createTempFile(
                tempName,
                ".png",
                storageDir

        );
        Log.d("e",image.getName());
        mCurrentPhotoPath = image.getAbsolutePath();
        return image;

    }

Log

D/e: 20190402
D/e: 201904021419980777854538831.png

Upvotes: 0

Views: 171

Answers (3)

Michael Altenburger
Michael Altenburger

Reputation: 1336

File.createTempFile lets you specifiy a prefix and suffix for the file created but you don't specify the full name as it has a random part in its name. If you want to have a file in the temp-directory with exactly that name, you would need to use something like this:

File image = new File(
        System.getProperty("java.io.tmpdir") , 
        tempName + 
        ".png"
    );

Upvotes: 1

chris
chris

Reputation: 86

Seems to be part of the createTempFile method itself. I was looking at docs and it says "Once these adjustments have been made the name of the new file will be generated by concatenating the prefix, five or more internally-generated characters, and the suffix.". It seems it generates random characters at the end to guarantee uniqueness.

What you can do I guess is store the file object somewhere you where you can access it where you need to and just get the first 6 characters which should be the date or you can just create a normal file. Also possible that maybe you can just rename the temporary file after creating it to only use first 6 characters? Not entirely sure

Upvotes: 0

Amine
Amine

Reputation: 2434

Simple answer, you can't change the name of the file created using createTempFile. It has a default unique name for each file.

Long answer,according to the https://docs.oracle.com/javase/7/docs/api/java/io/File.html#createTempFile(java.lang.String,%20java.lang.String,%20java.io.File) :

  1. The file denoted by the returned abstract pathname did not exist before this method was invoked, and
  2. Neither this method nor any of its variants will return the same abstract pathname again in the current invocation of the virtual machine.

Upvotes: 0

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