how would i add icon to my save file?

right now, i can save a file using JFileChooser, but how would i added an icon to the file that i saved?

Code:

---

                fileChooser.addChoosableFileFilter(new CLVFilter());
                int returnValue = fileChooser.showSaveDialog(frame);

                if(returnValue == JFileChooser.APPROVE_OPTION){
                        try{
                                //filename consists of path
                                String filename = fileChooser.getSelectedFile().toString();
                                FileWriter fstream = new FileWriter(filename);
                                BufferedWriter out = new BufferedWriter(fstream);

                                out.write(SingleIntersection.this.getContentsOfObject());
                                out.close();
                                               
                        }catch (Exception excep){//Catch exception if any
                                System.err.println("Error: " + excep.getMessage());
                        }
                }

---

Files don't directly have icons, but the operating system can have icons associated with a file type. You would need to do this association through your OS, and possibly not via Java.