Java.io.InputStream.mark() Method

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Description

The java.io.InputStream.mark(int readlimit) method marks the current position in this input stream. A subsequent invocation to the reset() method reposition the stream to the recently marked position.

Declaration

Following is the declaration for java.io.InputStream.mark(int readlimit) method −

public void mark(int readlimit)

Parameters

readlimit − The maximum number of bytes that can be read before the mark position becomes invalid.

Return Value

The method does not return any value.

Exception

NA

Example

The following example shows the usage of java.io.InputStream.mark(int readlimit) method.

package com.tutorialspoint;

import java.io.FileInputStream;
import java.io.InputStream;

public class InputStreamDemo {
   public static void main(String[] args) throws Exception {
      InputStream is = null;
            
      try {
         // new input stream created
         is = new FileInputStream("C://test.txt");
         
         // read and print characters one by one
         System.out.println("Char : "+(char)is.read());
         System.out.println("Char : "+(char)is.read());
         System.out.println("Char : "+(char)is.read());
                     
         // mark is set on the input stream
         is.mark(0);
         
         System.out.println("Char : "+(char)is.read());
         System.out.println("Char : "+(char)is.read());
         
         if(is.markSupported()) {
         
            // reset invoked if mark() is supported
            is.reset();
            System.out.println("Char : "+(char)is.read());
            System.out.println("Char : "+(char)is.read());
         }
         
      } catch(Exception e) {
         // if any I/O error occurs
         e.printStackTrace();
      } finally {
         // releases system resources associated with this stream
         if(is!=null)
            is.close();
      }
   }
}

Assuming we have a text file c:/test.txt, which has the following content. This file will be used as an input for our example program −

ABCDEF

Let us compile and run the above program, this will produce the following result −

Char : A
Char : B
Char : C
Char : D
Char : E