1.5 ignoring networkaddress.cache property?

[Nick Johnson]

I've noticed that 1.5 seems to be ignoring the value set for 
networkaddress.cache.negative.ttl in 
$JAVA_HOME/jre/lib/security/java.policy when a DNS request times out.

In one of my forms I validate user-provided URLs by trying to fetch them 
and ensuring I get a reasonable response (e.g., not 404, 403, 500, etc).

If the DNS request for the hostname in the URL times out once, the JRE 
never tries a lookup again.  I've verified that it isn't asking by 
snooping DNS traffic on my loopback with tcpdump.

Positive lookups do cache properly.  Negative lookups that *don't* time 
out (ie, they get an NXDOMAIN response) also seem to obey the 
networkaddress.cache.negative.ttl property.

So the behaviour seems to be that a DNS timeout is cached forever, whereas 
postive or negative responses are cached according to 
networkaddress.cache.*.

   Nick

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