From JSP I just want a redirect to another page...

<% response.sendRedirect("http://www.google.com/"); %>

Can I check if google.com is up and then redirect (or write a msg else)...

Something like that:

<% if(ping("www.google.com")) {
     response.sendRedirect("http://www.google.com/");
} else {
     // write a message 
}%>

Or

<% try {
     response.sendRedirect("http://www.google.com/");
} catch(SomeException e) {
     // write a message 
}%>

It is just an JSP page, I don't have any libraires available (like ApacheCommons for http GET methods).