LineNumberReader.mark(int readAheadLimit) has the following syntax.
public void mark(int readAheadLimit) throws IOException
In the following code shows how to use LineNumberReader.mark(int readAheadLimit) method.
// w w w . j av a 2s. co m import java.io.FileReader; import java.io.IOException; import java.io.LineNumberReader; public class Main { public static void main(String[] args) throws IOException { // create new reader FileReader fr = new FileReader("C:/test.txt"); LineNumberReader lnr = new LineNumberReader(fr); // reads and prints data from reader System.out.println((char) lnr.read()); System.out.println((char) lnr.read()); // mark invoked at this position lnr.mark(0); System.out.println("mark() invoked"); System.out.println((char) lnr.read()); System.out.println((char) lnr.read()); // if this reader supports mark() an reset() if (lnr.markSupported()) { // reset() repositioned the reader to the mark lnr.reset(); System.out.println("reset() invoked"); System.out.println((char) lnr.read()); System.out.println((char) lnr.read()); } lnr.close(); } }