It only would make any difference if you take out any DNS lookup at all by using InetAddress.getByAddress(byte) - any other way of creating a socket will perform at least some sort of DNS look up.
Also be aware of TLS - when you want to use something like SNI you have to do it on your own - wich quickly end up in a 20-line mess. Just using URL does it all for you.
TLDR: Unless you do it all low-level by yourself - nope - it doesn't make any significant difference.
So using a direct IP address will not give all that much of a performance gain. A cached DNS lookup may take only a few microseconds, and as I pointed out to a colleague years ago, you cannot save microseconds in a jar for later use - the use is going to spend countless microseconds drooling at the screen trying to make sense of what just came back.
A more important reason not to use direct IP addresses is that many sites these days host multiple web applications at the same IP address. That includes my own local server farm. So in order to get to the proper web application, you'll probably have to supply a FQDN in the URL request anyway.
Being persecuted doesn't in any way prove your righteousness or your beliefs. Many people get persecuted because they are repugnant or annoying. Or just because they can be.
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