How to replace a Document feeder kit

Question

I need a user guide to do this above subject matter.

Answer 1

String strToReplace = "replace me !!";
String replaceWith = "i replace the old string";
BufferedReader reader = new BufferedReader(new FileReader("./doc.rtf"));
PrintWriter writer = new PrintWriter(new FileWriter("./doc2.rtf"));
String currentLine = ""; String newLine = "";
while ((currentLine = reader.readLine()) != null) {
    newLine = currentLine.replace(strToReplace, replaceWith);
    writer.println(newLine);
    writer.flush();
reader.close();
writer.close();
(new File("./doc.rtf")).delete();
(new File("./doc2.rtf")).renameTo(new File("./doc.rtf"));something like that
be extremely cautious with this since this method delete the doc.rtf ; be sure to backup your doc.rtf file before doing anything else :)