问题:

HttpServletRequest.getRemoteAddr() in Tomcat returns IPv6 formatted IP address, but I would like to configure it that returns IPv4.

I access the servlet via 'localhost'. If I access it via '127.0.0.1' then returns IPv4 formatted IP address (see this answer).

Environment:

My LAN connection properties: IPv6 is checked off, but it doesn't work neither if I check it on.

回答1:

try adding this parameter -Djava.net.preferIPv4Stack=true to your tomcat startup commandline.

when you use localhost/xxx, your browser first have to find the mapped address for the name "localhost".In system host file you will find:

# 127.0.0.1 localhost

# ::1 localhost

both definition disabled by default.

to change browser's default matching rules, you have to enable the definition.

e.g: remove "#" from the first host file line, your brower will know directily "localhost" equals 127.0.0.1

Cheers