Class SocketSignalReceiver

All Implemented Interfaces:
Direct Known Subclasses:

public class SocketSignalReceiver extends AbstractSignalReceiver
A signal receiver implementation that listens on a socket for incoming signals. Accordingly, this receiver supports sending signals between different virtual machines running on different servers. The initialisation string for this class should be of the format:



  • The port is the port number the signal receiver will listen on. This is optional and if not given a random non-used port will be used.
  • The proxy is the address of a proxy host that will route incoming messages to this signal receiver. The proxy will automatically be added to the list of allowed hosts. This value is optional.
  • The forward attribute is a boolean option (1 or 0). If 1, this signal receiver will act as a proxy and forward signal messages which are of the form:


    Before the message is forwarded it is re-built like this:


  • The allow parts are the ip name or numbers of hosts that are allowed to send signals to the receiver. Except for the special case allow=*, which allows any remote host to send signals an exact match is required. The local host is always allowed to send signals.

    If no allow tags are given only allow connections from the local host (and the proxy if given) are allowed.

Last modified
$Date: 2015-05-12 11:27:08 +0200 (ti, 12 maj 2015) $
  • Field Details

    • logger

      private static final org.slf4j.Logger logger
      Log signals processing.
    • ip

      private InetAddress ip
    • listener

      private Thread listener
    • port

      private int port
    • proxy

      private String proxy
    • allowForward

      private boolean allowForward
    • allow

      private Set<InetAddress> allow
    • allowAll

      private boolean allowAll
  • Constructor Details

    • SocketSignalReceiver

      public SocketSignalReceiver()
      Create a new socket signal receiver. Before it can be used it must be initialised with init(String).
  • Method Details

    • init

      public void init(String params)
      Initialise the receiver. The given parameter should be the port number the receiver should listen on. If the parameter can't be parsed as a numeric value, a random free port will be used. This method will open the socket and start a separate thread that listens for incoming signals.
      Specified by:
      init in interface SignalReceiver
      init in class AbstractSignalReceiver
      params - The ID of the signal receiver, needed if the default ID generation should be used
    • getSignalTransporterClass

      public Class<? extends SignalTransporter> getSignalTransporterClass()
      Description copied from interface: SignalReceiver
      Get the signal transporter class that should be used to send signals to this receiver.
    • close

      public void close(int wait)
      Close this receiver and the socket it is listening on.
      Specified by:
      close in interface SignalReceiver
      close in class AbstractSignalReceiver
      wait - Number of milliseconds to wait for registered jobs to abort, use a negative value to disable notification, and 0 to disable waiting
    • getGlobalSignalId

      protected String getGlobalSignalId(SignalHandler handler)
      Override ID generation so we can add proxy information if needed.
      getGlobalSignalId in class AbstractSignalReceiver
      handler - The signal handler to generate the ID for
      The signal handler ID
    • processSignalMessage

      protected void processSignalMessage(String message)
      Process the incoming message. This class will check if the message contains any forwarding information. If so, the message will be forwarde to the new destination. Otherwise, the message will be processed as normal.
      processSignalMessage in class AbstractSignalReceiver
      message - The message to process, the format of the message must be compatible with the message that AbstractSignalTransporter.generateSignalMessage(Signal) generates
    • parseInitParameters

      protected void parseInitParameters(String params)
      Parse the initialisation parameters. Called from the init(String) method.
      params - Parameter string passed to init(String) method
    • listenOnSocket

      protected void listenOnSocket()
      Start listening for incoming signals.
    • forwardSignalMessageIfNeeded

      protected boolean forwardSignalMessageIfNeeded(String message)
      If the message has forwarding information, forward the message to the other host.
      TRUE if the message was forwarded, FALSE otherwise
    • isAllowedHost

      protected boolean isAllowedHost(InetAddress remoteHost)
      Checks if the specified remote host is allowed to send signals to this receiver.
      remoteHost - The remote host that is sending the signal
      TRUE if the host is allowed, FALSE otherwise