class palindrome
{
public static void main(String args[])

  {
    StringBuffer sb = new StringBuffer("nitin");
    System.out.println(sb);
    String sb1=sb.reverse();//error coming in this line why ?
    if(sb1.contentEquals(sb))
        {
        System.out.println("palindrome");
        }
    else
        {
        System.out.println("not a palindrome");
        }
  }
}

sb.reverse()// This will return a reference to StringBuffer

sb.reverse().toString()//This will convert it to a String

sb.reverse().toString()