Java tutorial
import java.io.FilterReader; import java.io.Reader; import java.io.StringReader; public class Main { public static void main(String[] args) throws Exception { // create new reader Reader r = new StringReader("ABCDEF"); // create new filter reader FilterReader fr = new FilterReader(r) { }; // tests if the filter reader supports mark() boolean bool = fr.markSupported(); // prints System.out.print("If mark() supported? " + bool); } }