Can java create unique filenames?

Question

DataOutputStream out = new DataOutputStream(new FileOutputStream(fileName));
String fileName = "c:/" + Integer.toString(stuff) + ".txt";
out.write(stuff);
The reason that this is important, is because I want to be able to create a unique filename each time I run the program (which records important data). I dont want the data overwritten within the same file over and over again.
currently my program looks like this:
DataOutputStream out = new DataOutputStream(new FileOutputStream("c:/data.txt"));
out.write(stuff);
each time I run the program however, the data.txt file will just get overwritten. How can I make my program resemble the one above without Java rejecting the codeing?

Answer 1

I defer to DrClap - it does seem to work. Usingthe following codeimport java.io.*;
public class Test {
    public static boolean createTempFile (String prefix, String suffix) {
        try {
            File.createTempFile(prefix, suffix);
        catch (IOException e) {
            return false;
        return true;
    public static void main( String [] args ) {
        System.out.println(Test.createTempFile("foo", "bar"));
        System.out.println(Test.createTempFile("bar", "foo"));
        System.out.println(Test.createTempFile("foo", "bar"));
}I get files of the form
fooNNNNNbar created. So my question is when would his EVER throw an IOException?