java - getByName() - how to elaborate on cause? -

with inetaddress.getbyname() able distinguish between

• the name service replied, , result negative

and

• the name service did not reply (no connectivity dns server or whatever)

i believe there's huge difference between 2 in terms of support, i.e. telling problem. it's difference between problem argument vs infrastructure problem.

so how can distinguish between two?

as see there's unknownhostexception in both cases , message text similar. ideas ?

code snippet clarify:

try {     inetaddress addr = inetaddress.getbyname(hostname); } catch (unknownhostexception ex) {     if ( ..... ) {         system.out.println("name server replied did not know \"" + hostname + "\"");     } else {         system.out.println("name server not contacted");     } } 

to specific: ..... in example ??

as extension, code try/catch function ping ip address given see response (as defined in (java code ping ip address) posting).

by doing so, use function , verify why problem occurred. might recommend testing in advance if possible (e.g. before try connect directly).