问题
I'm trying to create a datagramsocket with and datagrampacket to send with the keep-alive option. I'm confused about how to set this though. Is there a simple way to do it like datagramsocket.setKeepAlive(true); ?
EDIT: Sorry, I meant setting the time to live of a packet. Is there a way I can set it so if it isn't received, it will stay until it is received?
回答1:
UDP is what's called connectionless protocol, i.e. no connection is established, you just send packets to an ip address/port tuple. Since there is no connection, there is nothing to keep alive.
来源：https://stackoverflow.com/questions/9675187/java-datagramsocket-setting-keep-alive-option