Java FilterReader.mark(int readAheadLimit)

public void mark(int readAheadLimit)  throws IOException

/*from  w ww  .j  a v a 2 s.  co m*/
import java.io.FilterReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;

public class Main {
  public static void main(String[] args) throws Exception {

    Reader r = new StringReader("ABCDEF");

    // create new filter reader
    FilterReader fr = new FilterReader(r) {};

    // reads and prints FilterReader
    System.out.println((char) fr.read());
    System.out.println((char) fr.read());

    // mark invoked at this position
    fr.mark(0);
    System.out.println("mark() invoked");
    System.out.println((char) fr.read());
    System.out.println((char) fr.read());

    // reset() repositioned the stream to the mark
    fr.reset();
    System.out.println("reset() invoked");
    System.out.println((char) fr.read());
    System.out.println((char) fr.read());

  }
}