Module org.newsclub.net.unix
Package org.newsclub.net.unix

Enum Class AFSocketCapability

java.lang.Object
java.lang.Enum<AFSocketCapability>
org.newsclub.net.unix.AFSocketCapability
All Implemented Interfaces:
Serializable, Comparable<AFSocketCapability>, Constable
public enum AFSocketCapability extends Enum<AFSocketCapability>
Describes junixsocket capabilities the current environment (system platform, native library, etc.) may or may not support. You can check whether your environment supports a given capability by calling AFSocket.supports(AFSocketCapability). You can also manually disable a given capability by specifying a System property of the form org.newsclub.net.unix.library.disable.CAPABILITY_SOMETHING_SOMETHING=true when invoking the JVM (make sure this property is set before junixsocket is accessed). A simple way to check which capabilities are supported in an environment is to run the `junixsocket-selftest` jar.

  • Enum Constant Details

    • CAPABILITY_PEER_CREDENTIALS

      public static final AFSocketCapability CAPABILITY_PEER_CREDENTIALS
      Socket supports retrieving peer credentials.

    • CAPABILITY_ANCILLARY_MESSAGES

      public static final AFSocketCapability CAPABILITY_ANCILLARY_MESSAGES
      Socket supports sending and receiving ancillary messages.

    • CAPABILITY_FILE_DESCRIPTORS

      public static final AFSocketCapability CAPABILITY_FILE_DESCRIPTORS
      Socket supports passing file descriptors via ancillary messages.

    • CAPABILITY_ABSTRACT_NAMESPACE

      public static final AFSocketCapability CAPABILITY_ABSTRACT_NAMESPACE
      Socket addressing supports the abstract namespace (Linux).

    • CAPABILITY_UNIX_DATAGRAMS

      public static final AFSocketCapability CAPABILITY_UNIX_DATAGRAMS
      Support for AF_UNIX datagrams.

    • CAPABILITY_NATIVE_SOCKETPAIR

      public static final AFSocketCapability CAPABILITY_NATIVE_SOCKETPAIR
      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.

    • CAPABILITY_FD_AS_REDIRECT

      public static final AFSocketCapability CAPABILITY_FD_AS_REDIRECT
      A file descriptor can be converted to ProcessBuilder.Redirect. This feature currently uses Java SDK internals that may change/disappear.

    • CAPABILITY_TIPC

      public static final AFSocketCapability CAPABILITY_TIPC
      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.

    • CAPABILITY_UNIX_DOMAIN

      public static final AFSocketCapability CAPABILITY_UNIX_DOMAIN
      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. NOTE: While this capability is typically supported on most systems that can actually load a junixsocket JNI library, it is unavailable for older Windows versions (such as 8.1, 10 before AFUNIX.SYS was included, etc.) and on systems where support for UNIX domain sockets is actively disabled. Therefore, it is still recommended to check for this capability.

    • CAPABILITY_VSOCK

      public static final AFSocketCapability CAPABILITY_VSOCK
      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

      public static final AFSocketCapability 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.

    • CAPABILITY_ZERO_LENGTH_SEND

      public static final AFSocketCapability CAPABILITY_ZERO_LENGTH_SEND
      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.

    • CAPABILITY_UNSAFE

      public static final AFSocketCapability CAPABILITY_UNSAFE
      Support for "unsafe" operations. Trading-in safety for speed or simplicity may be justified sometimes.
      See Also:

    • CAPABILITY_LARGE_PORTS

      public static final AFSocketCapability CAPABILITY_LARGE_PORTS
      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.

    • CAPABILITY_DARWIN

      public static final AFSocketCapability CAPABILITY_DARWIN
      Support for certain Darwin (macOS Kernel)-specific features, such as the AF_SYSTEM domain.

  • Method Details

    • values

      public static AFSocketCapability[] values()
      Returns an array containing the constants of this enum class, in the order they are declared.
      Returns:
      an array containing the constants of this enum class, in the order they are declared

    • valueOf

      public static AFSocketCapability valueOf(String name)
      Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)
      Parameters:
      name - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum class has no constant with the specified name
      NullPointerException - if the argument is null