How to delete this file

Question

I would like to delete an existing file so I can create a new version of it (I want to delete it to prevent update problems).
Tried lots but it never actually deletes it. Any suggestions on how to solve the problem?
Thanks.
public void writeToFile(String message, String userName){
      (userName+".wri").delete();  //delete the file
     try{    File diaryFile = new File (userName+".wri");
     diaryFile = new File (userName+".wri");
     RandomAccessFile raf = new RandomAccessFile(diaryFile,"rw");
    raf.writeBytes(message);
    catch (Exception e)
    {     System.out.println(e);}

Answer 1

You're not trying to delete a File, you're trying to call delete() on a String:
(userName+".wri").delete();To delete a File, do this:
File file = new File(filename);
file.delete();