On 18/12/2019 16:47, Chris Hegarty wrote:
:
Specifically on this point, the two-arg variants of `joinGroup` and
`leaveGroup` throw an UnsupportedOperationException if invoked on a
MulticastSocket that has a DatagramSocketImpl which was compiled against
a pre-1.4 version of the DSI interface. ( these abstract methods were
only added to the DSI interface in Java 1.4 )
That's right. There are also several setter/getter methods that require
the impl to support socket options that were added in Java SE 1.4, e.g.
setNetworkInterface requires the impl to support IP_MULTICAST_IF2,
setLoopbackmode requires it to support IP_MULTICAST_LOOP. There are
examples in DatagramSocket with methods such as setTrafficClass and
setBroadcast. There's a lot more detail that we could go into, such as
the changes to the FileDescriptor representation in JDK 5 but I think
we've got enough here to conclude that dropping support for
DatagramSocketImpl compiled with JDK 1.3 or older should not be a
compatibility concern in 2019.
-Alan
