Replace default DNS name resolution in Java

Question

I'd like to change the way the JVM resolves domain names in HttpURLConnections.

Instead of going to DNS servers through the default TCP/IP stack I wanted to write my own code to resolve domain names.

Is there a way to replace the default name resolution mechanism?

Answer 1

i have no idea if it would work, but there are system properties

System.setProperty("sun.net.spi.nameservice.nameservers", localhost); System.setProperty("sun.net.spi.nameservice.provider.1", "dns,sun");

perhaps if you have your java application open a port on the dns port (53) and process requests yourself.

Of course this falls down if there is a dns server already on the current machine.

Answer 2

Construct URLs replacing the hostname with the numeric IP address and then add the Host header manually to the HttpUrlConnection.

http://www.myserver.com/foo.html

Is equivalent to

http://192.168.1.100/foo.html
Host: www.myserver.com

dnsjava gives you more control in resolving DNS names over the standard Java APIs.