This is rubbish!!

Question

Hey Servlet/JSP programmers! Want to see some fun? I am not sure if you've already seen this, but i saw it first time today.
Do one thing - Paste following lines of code in one file. Call it "OSTest.jsp" and access it thro' browser.
<%@ page import="java.io.*"%>
<%
response.getOutputStream().write("This is rubbish!".getBytes());
%>
You'll get exception: getOutputStream() has already been called for this response!
Where did I call it before?
Now remove first line(<%@ page import="java.io.*"%>), save and access again.
No error! "This is rubbish!" printed!
Any comments?

Answer 1

Yes kuldeepchaturvedi, you are right. But the funny
thing about this is that the JSP compiler generates
one extra line i.e.
out.write("\r\n");
when we include this line:
<%@ page import="java.io.*"%>
at the top. And it does not include it when we remove
that line. I wonder if this is a bug.
So friends if you want to play with the response's
s OutputStream, Do not include <%@ page
import="java.io.*"%> at the top, atleast in
Tomcat4.1.24.It includes it because you put a return carrige after typing the line. Any characters, returns and spaces, that are put outside of <% %> are written out with out.println();