You can say:

import java.util.Scanner;

public class ScannerTester
{

public static void main ( String[] args )
{
Scanner aScanner_input = new Scanner( System.in );
String aScanner;

  aScanner = aScanner\_input.next();

  if ( sScanner == "s" )
  {
     System.out.println("aScanner is s!");
  }

  if ( aScanner == "Y" )
  {
     System.out.println("aScanner is Y!");
  }

}
}