Método ByteArrayInputStream markSupported() en Java con ejemplos

El método markSupported() es un método integrado del método Java.io.ByteArrayInputStream que comprueba si este flujo de entrada es compatible con los métodos de marcar y restablecer. El método markSupported de ByteArrayInputStreamInputStream siempre devuelve verdadero

Sintaxis : 

public boolean markSupported()

Parámetros : La función no acepta ningún parámetro. 
Valor devuelto : la función devuelve un valor booleano. Devuelve verdadero si esta instancia de transmisión es compatible con los métodos de marcar y restablecer, de lo contrario, es falso.

A continuación se muestra la implementación de la función anterior:

Programa 1:  

// Java program to implement
// the above function
import java.io.*;
 
public class Main {
    public static void main(String[] args) throws Exception
    {
 
        byte[] buf = { 5, 6, 7, 8, 9 };
 
        // Create new byte array input stream
        ByteArrayInputStream exam
            = new ByteArrayInputStream(buf);
 
        // print bytes
        System.out.println(exam.read());
        System.out.println(exam.read());
        System.out.println(exam.read());
 
        System.out.println("Mark() invocation");
 
        // Use of markSupported
        boolean check = exam.markSupported();
        System.out.println("markSupported() : "
                           + check);
 
        if (exam.markSupported()) {
 
            // Use of reset() method :
            // repositioning the stream to marked positions.
            exam.reset();
 
            System.out.println("\nreset() invoked");
            System.out.println(exam.read());
            System.out.println(exam.read());
        }
        else {
            System.out.println("reset() method not supported.");
        }
    }
}

5
6
7
Mark() invocation
markSupported() : true

reset() invoked
5
6

Programa 2: 

// Java program to implement
// the above function
import java.io.*;
 
public class Main {
    public static void main(String[] args) throws Exception
    {
 
        byte[] buf = { 1, 2, 3 };
 
        // Create new byte array input stream
        ByteArrayInputStream exam
            = new ByteArrayInputStream(buf);
 
        // print bytes
        System.out.println(exam.read());
        System.out.println(exam.read());
        System.out.println(exam.read());
 
        // Use of markSupported
        boolean check = exam.markSupported();
 
        System.out.println("markSupported() : "
                           + check);
 
        if (exam.markSupported()) {
 
            // Use of reset() method :
            // repositioning the stream to marked positions
            exam.reset();
 
            System.out.println("\nreset() invoked");
            System.out.println(exam.read());
            System.out.println(exam.read());
        }
        else {
            System.out.println("reset() method not supported.");
        }
    }
}

1
2
3
markSupported() : true

reset() invoked
1
2

Referencia: https://docs.oracle.com/javase/10/docs/api/java/io/ByteArrayInputStream.html#markSupported()