screenshot saving as autogenerated file name

Question

I made a button to take the screenshot and save into Pictures folder. I set it as being saved under the name capture.jpeg but I wanted it to be saved as such as cafe001.jpeg

Answer 1

To save as another name just change the string "capture.jpeg"

If you want to have it as cafeXXX.jpeg (where XXX is a number) then you could do something like this (this method could potentially cause number overlaps however if files are deleted):

int count = 1;
File picturesDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File[] content = picturesDir.listFiles();
for (File f: content)
{
    if (f.getName().matches("cafe\\d+\\.jpeg"))
        count++;
}
//... your other code
// if leading zeros important then add formatting code to the count
fos = new FileOutputStream(picturesDir.toString() + "cafe"+count+".jpeg");

If you want a timeformat just use SimpleDateFormat changing the format String as required (as only going to day will mean you will only get time format per day)

String timeFileName = new SimpleDateFormat("yyyy-MM-dd").format(new Date())
//...other code
fos = new FileOutputStream(picturesDir.toString() + timeFileName+".jpeg");

Answer 2

You basically have a couple of choices...

You could...

List all the files in the directory and simple increment the file count by 1 and use that...

File[] files = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString()).
    listFiles(new FileFilter() {
        public boolean accept(File pathname) {
            String name = pathname.getName();
            return pathname.isFile() && name.toLowerCase().startsWith("capture") && name.toLowerCase().endsWith(".jpeg");
        }
});

int fileCount = files.length();

fos = new FileOutputStream(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString() + 
    "capture" + fileCount + ".jpeg");

This, of course, doesn't take into account if a file with the same index exists...

You could...

List all the files, sort them, grab the last one, find it's index value and increment that...

Something like...

File[] files = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).toString()).
    listFiles(new FileFilter() {
        public boolean accept(File pathname) {
            String name = pathname.getName();
            return pathname.isFile() && name.toLowerCase().startsWith("capture") && name.toLowerCase().endsWith(".jpeg");
        }
});

Arrays.sort(files);
File last = files[files.length - 1];

Pattern pattern = Pattern.compile("[0-9]+");
Matcher matcher = pattern.matcher(last.getName());

int index = 1;
if (matcher.find()) {
    String match = matcher.group();
    index = Integer.parseInt(match) + 1;
}

String fileName = "capture" + index + ".jpeg"

You could...

Simply create a loop and loop until you find an empty index position...for example see, Java autogenerate directories if exists