Ghi file (dùng PrintStream)
try{
File f = new File(tenFile);
if(!f.exists()){
PrintStream out = new PrintStream(f);
// out.print(…) or out.println(….) viet vao file nhu System.out.print
out.close();
}else System.out.println(" file da ton tai ");
}catch(Exception e){
System.out.println(e.getMessage());
}