Re: do you get error in this url?

From:

Lew <noone@lewscanon.com>

Newsgroups:

comp.lang.java.help

Date:

Sat, 25 Jul 2009 09:21:11 -0400

Message-ID:

<h4f0s8$sd2$1@news.albasani.net>

maya wrote:

yes, of course, I just don't understand how getting user-agent can
return a value of "null"..

If the client does not send a "User-Agent" header, a request for the value of
that (nonexistent) header will perforce return 'null'.

Lew wrote:

And yet the docs clearly state that this particular method can return
a value of 'null'.

maya wrote:

that's just it, Lew, it doesn't....
http://tomcat.apache.org/tomcat-5.5-doc/servletapi/javax/servlet/http/HttpServletRequest.html

java.lang.String getHeader(java.lang.String name)
Returns the value of the specified request header as a String.

It's a little odd to link to the Tomcat docs rather than to
<http://java.sun.com/javaee/6/docs/api/javax/servlet/http/HttpServletRequest.html#getHeader(java.lang.String)>
but since they say the exact same thing, it doesn't matter. You only quoted
the summary. Look again at the actual detailed docs for the method:
<http://tomcat.apache.org/tomcat-5.5-doc/servletapi/javax/servlet/http/HttpServletRequest.html#getHeader(java.lang.String)>

It clearly says:

If the request did not include a header of the specified name,
this method returns null.

How can you claim that it doesn't?

Please, follow either of these links that I (again) provided. Read it. The
reference to a 'null' return is right there in plain sight. I promise.

--
Lew