Package org.jgroups.protocols

Class STOMP

  • All Implemented Interfaces:
    java.lang.Runnable, Lifecycle
    public class STOMP
extends Protocol
implements java.lang.Runnable
    Protocol which provides STOMP (https://stomp.github.io/) support. Very simple implementation, with a one-thread-per-connection model. Use for a few hundred clients max.

    The intended use for this protocol is pub-sub with clients which handle text messages, e.g. stock updates, SMS messages to mobile clients, SNMP traps etc.

    Note that the full STOMP protocol has not yet been implemented, e.g. transactions are not supported. todo: use a thread pool to handle incoming frames and to send messages to clients

    todo: add PING to test health of client connections

    Since:
    2.11
    Author:
    Bela Ban

    • Field Detail

      • bind_addr

        protected java.net.InetAddress bind_addr

      • endpoint_addr

        protected java.lang.String endpoint_addr

      • port

        protected int port

      • exact_destination_match

        protected boolean exact_destination_match

      • send_info

        protected boolean send_info

      • forward_non_client_generated_msgs

        protected boolean forward_non_client_generated_msgs

      • srv_sock

        protected java.net.ServerSocket srv_sock

      • endpoint

        protected java.lang.String endpoint

      • acceptor

        protected java.lang.Thread acceptor

      • endpoints

        protected final java.util.Map<Address,​java.lang.String> endpoints

      • view

        protected View view

      • subscriptions

        protected final java.util.concurrent.ConcurrentMap<java.lang.String,​java.util.Set<STOMP.Connection>> subscriptions

    • Constructor Detail

      • STOMP

        public STOMP()

    • Method Detail

      • getNumConnections

        public int getNumConnections()

      • getNumSubscriptions

        public int getNumSubscriptions()

      • getSubscriptions

        public java.lang.String getSubscriptions()

      • getEndpoints

        public java.lang.String getEndpoints()

      • start

        public void start()
           throws java.lang.Exception
        Description copied from class: Protocol
        This method is called on a JChannel.connect(String); starts work. Protocols are connected ready to receive events. Will be called from bottom to top.
        Specified by:
        start in interface Lifecycle
        Overrides:
        start in class Protocol
        Throws:
        java.lang.Exception - Thrown if protocol cannot be started successfully. This will cause the ProtocolStack to fail, so JChannel.connect(String) will throw an exception

      • run

        public void run()
        Specified by:
        run in interface java.lang.Runnable

      • down

        public java.lang.Object down​(Event evt)
        Description copied from class: Protocol
        An event is to be sent down the stack. A protocol may want to examine its type and perform some action on it, depending on the event's type. If the event is a message MSG, then the protocol may need to add a header to it (or do nothing at all) before sending it down the stack using down_prot.down().
        Overrides:
        down in class Protocol

      • up

        public java.lang.Object up​(Event evt)
        Description copied from class: Protocol
        An event was received from the protocol below. Usually the current protocol will want to examine the event type and - depending on its type - perform some computation (e.g. removing headers from a MSG event type, or updating the internal membership list when receiving a VIEW_CHANGE event). Finally, the event is either a) discarded, or b) an event is sent down the stack using down_prot.down() or c) the event (or another event) is sent up the stack using up_prot.up().
        Overrides:
        up in class Protocol

      • up

        public java.lang.Object up​(Message msg)
        Description copied from class: Protocol
        A single message was received. Protocols may examine the message and do something (e.g. add a header) with it before passing it up.
        Overrides:
        up in class Protocol

      • up

        public void up​(MessageBatch batch)
        Description copied from class: Protocol
        Sends up a multiple messages in a MessageBatch. The sender of the batch is always the same, and so is the destination (null == multicast messages). Messages in a batch can be OOB messages, regular messages, or mixed messages, although the transport itself will create initial MessageBatches that contain only either OOB or regular messages.

        The default processing below sends messages up the stack individually, based on a matching criteria (calling Protocol.accept(Message)), and - if true - calls Protocol.up(org.jgroups.Event) for that message and removes the message. If the batch is not empty, it is passed up, or else it is dropped.

        Subclasses should check if there are any messages destined for them (e.g. using MessageBatch.iterator(Predicate)), then possibly remove and process them and finally pass the batch up to the next protocol. Protocols can also modify messages in place, e.g. ENCRYPT could decrypt all encrypted messages in the batch, not remove them, and pass the batch up when done.

        Overrides:
        up in class Protocol
        Parameters:
        batch - The message batch

      • readFrame

        public static STOMP.Frame readFrame​(java.io.DataInputStream in)
                             throws java.io.IOException
        Throws:
        java.io.IOException

      • handleView

        protected void handleView​(View view)

      • getAllEndpoints

        protected java.lang.String getAllEndpoints()

      • broadcastEndpoint

        protected void broadcastEndpoint()