ServerSocket IP地址= :: / ::

Question

While debugging my ServerSocket object, I got this expression ServerSocket[addr=::/::,localport=32882] . What does the ::/:: address mean please?

Answer 1

::(consecutive colons) is used when you have all zeros in the whole block.

Example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334

Refer Wikipedia for IPV6 Addresses

One or more consecutive groups of zero value may be replaced with a single empty group using two consecutive colons (::), 1 but the substitution may only be applied once in the address, because multiple occurrences would create an ambiguous representation.

The example address can be further simplified: 2001:db8:85a3::8a2e:370:7334

Considering your case, IP Address contains all zeros(ie 0.0.0.0)