Java.io.ByteArrayInputStream.markSupported() Method

Description

The java.io.ByteArrayInputStream.markSupported() method returns true if the input stream supports mark() and reset() methods invocations. For ByteArrayInputStream the method always returns true.

Declaration

Following is the declaration for java.io.ByteArrayInputStream.markSupported() method:

public boolean markSupported()

Parameters

• NA

Return Value

This method returns true for ByteArrayInputStream

Exception

• NA

Example

The following example shows the usage of java.io.ByteArrayInputStream.markSupported() method.

package com.tutorialspoint;

import java.io.ByteArrayInputStream;
import java.io.IOException;

public class ByteArratInputStreamDemo {
   public static void main(String[] args) throws IOException {
      
      byte[] buf = {65, 66, 67, 68, 69};
      ByteArrayInputStream bais = null;
      
      try{
         
         // create new byte array input stream
         bais = new ByteArrayInputStream(buf);
         
         // test support for mark() and reset() methods invocation
         boolean isMarkSupported = bais.markSupported();
         System.out.println("Is mark supported : "+isMarkSupported);
         System.out.println("Following is the proof:");
         
         // print bytes
         System.out.println("Byte read "+ bais.read());
         System.out.println("Byte read "+ bais.read());
         System.out.println("Byte read "+ bais.read());
         
         System.out.println("Mark() invocation");

         // mark() invocation;
         bais.mark(0);
         System.out.println("Byte read "+ bais.read());
         System.out.println("Byte read "+ bais.read());
         
         System.out.println("Reset() invocation");
         
         // reset() invocation
         bais.reset();
         System.out.println("Byte read "+ bais.read());
         System.out.println("Byte read "+ bais.read());
         
      }catch(Exception e){

         // if I/O error occurs
         e.printStackTrace();
      }finally{
         if(bais!=null)
            bais.close();
      }   
   }
}

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

Is mark supported : true
Following is the proof:
Byte read 65
Byte read 66
Byte read 67
Mark() invocation
Byte read 68
Byte read 69
Reset() invocation
Byte read 68
Byte read 69