How can I write consecutive named files in Java?

Question

I have a method for saving a File, but I don't know how to save files with consecutive names such as file001.txt, file002.txt, file003.txt, filennn.text

How can I achieve this?

Answer 1

You can use the following line of code to create the filenames.

String filename = String.format("file%03d.txt", fileNumber);

Then you will just use that string to create new files:

File file = new File(filename);

The following code will create files numbered 1 - 100:

for (int fileNumber = 1; fileNumber <= 100; fileNumber++) {
    String filename = String.format("file%03d.txt", fileNumber);
    File file = new File(filename);
}

Or, you will need to have a static variable that you increment every time you create a new file.

private static int fileNumber = 0;
public void createNewFile(){
    String filename = String.format("file%03d.txt", fileNumber++);
    File file = new File(filename);
}

Answer 2

It may be desirable for you to skip over writing to a file if it already exists.

This could be done easily by placing the following at the beginning of the for loop proposed by Justin 'jjnguy' Nelson, for example:

if(new File(fileName).exists())
{
    continue;
}