Java at 30: Interview with James Gosling

The java.net.Inet4Address and Inet6Address could be more lightweight.

For a simple IPv4 address normally representable using 4 bytes/ 32 bits Java uses 56 bytes. The reason for it is Inet4Address object takes 24 B and the InetAddressHolder object takes another 32 B. The InetAddressHolder can contain not only the address but also the address family and original hostname that was possibly resolved to the address.

For an IPv6 address normally representable using 16 bytes/ 128 bits Java uses 120 bytes. An Inet6Address contains the InetAddressHolder inherited from InetAddress and adds an Inet6AddressHolder that has additional information such as the scope of the address and a byte array containing the actual address. This is an interesting approach especially when compared to the implementation of UUID, which uses two longs for storing the 128 bits of data.

Java's approach is causing 15x overhead for IPv4 and 7.5x overhead for IPv6 which seems excessive. What am I missing here? Can or should this be streamlined?

What a wonderfully HN response to a biographical piece on James Gosling.

For my part, most of the Java code that I have written that needs to use IP addresses needs somewhere between 1 and 10 of them, so I'd never notice this overhead. If you want to write, like, a BGP server in Java I guess you should write your own class for handling IP addresses.