JFileChooser c= new JFileChooser();
c.showOpenDialog(c);
File write_file = c.getSelectedFile();
String Content = "put here the data to be wriiten";
try
{
FileWriter fw = new FileWriter(write_file);
BufferedWriter bw = new BufferedWriter(fw);
bw.append(Content);
bw.append("hiiiii");
bw.close();
fw.close();
}
catch(Exception e)
{
System.out.println(e);
`}