How should HttpServletResponse.setHeader method do with null value?

Question

How should HttpServletResponse.setHeader method do with null value as below:

response.setHeader("ETag", null);

While implementing Servlet interface, I am a little bit confused on this because the Java Servlet Specification looks not clear about this.

I think I can choose one of these:

In practice, Tomcat's implementation just ignore. And netty, even if it is not a Servlet implmentation, throws NullPointerException.

Looks like this will be handled based on the servlet container or web application server implementation to handle this. — Luiggi Mendoza, Jul 30 '13 at 04:51

score 0 · Answer 1 · answered Jul 30 '13 at 09:21

0

According to W3C spec, the ETag values must be double quoted. You can either choose "do nothing" option, or add spec-conformed entity tag header

ETag: "some-etag-value"

answered Jul 30 '13 at 09:21

Erhan Bagdemir

Yes, it is a correct behavior of HTTP Server for ETag header. But I think setHeader method doesn't need to consider about which header is set. What I want to know is the correct behavior of setHeader method which obeys Java Servlet Specification. – npcode Jul 30 '13 at 10:06

1 Answers1