import java.io.*;

 

public class FileCopierBuffered {

  public static void main(String[] args) throws IOException {

    FileInputStream fin = new FileInputStream("myFile.txt");

    BufferedInputStream bin = new BufferedInputStream(fin);

    System.out.println("Is markable? " + bin.markSupported());

    FileOutputStream fout = new FileOutputStream("myFileOut.txt", true);

    BufferedOutputStream bout = new BufferedOutputStream(fout);

    int b = bin.read();

    boolean markDone = false;

    boolean resetDone = false;

    while (b != -1) {

      char ch = (char) b;

      System.out.println(ch);

      if ((ch == 'c') && !markDone) {

        bin.mark(512);

        markDone = true;

      }

      if ((ch == 'd') && !resetDone) {

        bin.reset();

        resetDone = true;

      }

      bout.write(ch);

      b = bin.read();

    }

    bout.close();

    bin.close();

  }

}

If input file contains:

aaaa

bbbb

cccc

dddd

Output file will contain:

aaaa

bbbb

cccc

dccc

dddd

We marked after the first c and then reset after the first d.

To avoid marking and resetting again and again we have used two Boolean variables markDone and resetDone and will set them on first marking and first resetting respectively.