public final Enum AFSocketCapability

Socket addressing supports the abstract namespace (Linux).

Socket supports sending and receiving ancillary messages.

Support for certain Darwin (macOS Kernel)-specific features, such as the AF_SYSTEM domain.

A file descriptor can be converted to Redirect. This feature currently uses Java SDK internals that may change/disappear.

Socket supports passing file descriptors via ancillary messages.

Support for port numbers larger than 65535 (0xffff). Not all systems allow setting port numbers beyond the default TCP range (we use JNI tricks for that). This capability is required for RMI support.

A pair of interconnected sockets can be created natively as AF_UNIX sockets. This currently not possible on Windows, but instead emulated via anonymous AF_INET ports when you use AFSocketPair. Other systems may provide partial implementations of pipe-based (i.e., non-socket) pairs. This capability is specific to AF_UNIX sockets. Other sockets, such as AF_VSOCK, may not implement socketpair natively even if this capability is set, but would work-around that limitation in a similar fashion but maybe without resorting to AF_INET.

Socket supports retrieving peer credentials.

Support for AF_TIPC. Availability of this feature is checked upon launch and therefore loading the "tipc" kernel module at a later point may not be properly reflected.

Support for AF_UNIX datagrams.

Support for AF_UNIX. Availability of this feature is checked upon launch and therefore, on systems adding support at a later point, may not be properly reflected when checking at a later point.

Support for "unsafe" operations. Trading-in safety for speed or simplicity may be justified sometimes.

See Also

Unsafe, AFSocket#ensureUnsafeSupported()

Support for AF_VSOCK. Availability of this feature is checked upon launch and therefore enabling vsock at a later point may not be properly reflected.

See Also

CAPABILITY_VSOCK_DGRAM

Support for AF_VSOCK datagrams (not all platforms/kernel versions or configurations support this). Availability of this feature is checked upon launch and therefore enabling vsock at a later point may not be properly reflected.

Support for zero-length send(2). This can be used to perform a connection check, but not all operating systems support this or behave correctly (particularly, IBM AIX, IBM i, and IBM z/OS) at the moment. If not supported, junixsocket will simply ignore writes of zero-length, and connection checking with AFSocket#checkConnectionClosed() may return false regardless of the actual condition.