CoTreceiver

A Cursor on Target listener and message parser

CoT messages are XML messages that are sent either UDP or TCP. Once the CoT XML is received it can be parsed and the data used to perform some function.

UDP and TCP listeners are provided, as well as a helper class that allows multiple listeners to be managed from a single class.

• CoTudpListener.java
• CoTtcpListener.java
• CoTconnectors.java

The parsing of the CoT XML occurs in the CoTparser class. This class should be extended and the coTeventHandler method overridden for custom CoT data handling.

• CoTparser.coTeventHandler()

The process to receive and parse CoT messages passed as UDP or TCP is generally the following:

I.) Create a custom implementation of the CoTparser class and override the coTeventHandler() method. This method receives the CoT message (or event) as an XML string. See the CoTparser.dumpCoTevent() method for an example of how to extract nearly all of the CoT message data.

II.) Create a UDP or TCP listener. This can be done by invoking the listeners directly (CoTudpListener, CoTtcpListener) or using the connectors class (CoTconnectors) which allows the management of multiple listeners.

Example I:

• Create a custom CoTparser class. See CustomCoTparser.java.

• Override the coTeventHandler() to add your custom CoT data handling.

• Invoke the customized parser:

  CustomCoTparser cp = new CustomCoTparser();
  

Example II.a: Invoke a TCP listener

• Create a TCP listener directly

  CoTtcpListener cotTcpListener = new CoTtcpListener(cotTcpPort); <-- DEBUG is false by default

  CoTtcpListener cotTcpListener = new CoTtcpListener(cotTcpPort, debug); <-- DEBUG is set by developer

  CoTtcpListener cotTcpListener = new CoTtcpListener(9998, true);
  

• Assign the custom parser to the listener

  cotTcpListener.setCoTparser(cp);
  

• start the TCP listener

  cotTcpListener.start();
  

• Stop the TCP listener

  cotTcpListener.stopThread();
  

Note that threads cannot be restarted. If you desire to restart the listener you will have to re-invoke and set the custom parser:

  cotTcpListener = new CoTtcpListener(9998, true);
  cotTcpListener.setCoTparser(cp);

Example II.b: Invoke a UDP listener

• Create a UDP listener directly

  CoTudpListener cotUdpListener = new CoTudpListener(cotUdpPort); <-- DEBUG is false by default

  CoTudpListener cotUdpListener = new CoTudpListener(cotUdpPort, debug); <-- DEBUG is set by developer

  CoTudpListener cotUdpListener = new CoTudpListener(cotUdpPort, packetSize); <-- Set the UDP packet size, default = 1024 bytes

  CoTudpListener cotUdpListener = new CoTudpListener(cotUdpPort, packetSize, debug);

  CoTudpListener cotUdpListener = new CoTudpListener(9999, 2048, true);
  

• Assign the custom parser to the listener

  cotUdpListener.setCoTparser(cp);
  

• start the UDP listener

  cotUdpListener.start();
  

• Stop the UDP listener

  cotUdpListener.stopThread();
  

Note that threads cannot be restarted. If you desire to restart the listener you will have to re-invoke and set the custom parser:

  cotUdpListener = new CoTudpListener(9999, 2048, true);
  cotUdpListener.setCoTparser(cp);

Example II.c: Manage several UDP and TCP listeners

• Create a CoT connector

  CoTconnectors connectors = new CoTconnectors();
  

• Assign the custom parser to be used by the listeners. Note that the CoT custom parser must be assigned before the listeners are started.

  connectors.setCoTparser(cp);
  

• Add UPD and TCP listeners to the connectors object

  The UDP and TCP listeners are added with methods that take the same parameters as used when invoking the listeners directly.

  connectors.addTcpListener(cotTcpPort);

  connectors.addTcpListener(cotTcpPort, debug);

  connectors.addUdpListener(cotUdpPort);

  connectors.addUdpListener(cotUdpPort, debug);

  connectors.addUdpListener(cotUdpPort, packetSize);

  connectors.addUdpListener(cotUdpPort, packetSize, debug);

  connectors.addTcpListener(10000);
  connectors.addUdpListener(10001);
  connectors.addTcpListener(9998, true);
  connectors.addUdpListener(9999, 2048, true);
  

• List all the ports

  Integer[] ports = connectors.getPorts();
  for (int i = 0; i < ports.length; i++) {
      int p = ports[i];
      System.out.println("Listener port: " + p + " " + connectors.getPortType(p));
  }
  int p = 666;
  System.out.println("Test invalid port: " + p + " " + connectors.getPortType(p));
  

• Get the state of all the listeners (using the returned ports array)

  for (int i = 0; i < ports.length; i++) {
      p = ports[i];
      System.out.println("Listener state port: " + p + " " + connectors.getState(p));
  }
  

• Start all the listeners by port

  Note: the custom CoT parser must be set before calling the start methods

  connectors.startListener(10000);
  connectors.startListener(10001);
  connectors.startListener(9998);
  connectors.startListener(9999);
  

• Get the state of the ports (explicitly as opposed to the ports array used in the example above)

  System.out.println("Listener state port: 10000 " + connectors.getState(10000));
  System.out.println("Listener state port: 10001 " + connectors.getState(10001));
  System.out.println("Listener state port: 9998 " + connectors.getState(9998));
  System.out.println("Listener state port: 9999 " + connectors.getState(9999));
  

• Stop all the listeners explicitly

  connectors.stopListener(10000);
  connectors.stopListener(10001);
  connectors.stopListener(9998);
  connectors.stopListener(9999);
  

• Common usage example:

   System.out.println("\n\nStarting listener pool\n");
   connectors.setCoTparser(cp);
   connectors.addTcpListener(9998, true);
   connectors.addUdpListener(9999, 1024, false);
   connectors.startListener(9998);
   connectors.startListener(9999);
  
   ports = connectors.getPorts();
   for (int i = 0; i < ports.length; i++) {
       p = ports[i];
       System.out.println("port: " + p + " " + connectors.getPortType(p)+" "+connectors.getState(p));
   }