kottakcot

Kotlin TAK Cursor-on-Target (CoT) library.

KotTAKCoT can parse and build CoT 2.0 messages either in XML or Google ProtoBuf format compatible with the messages exchanged by ATAK/CivTAK.

The library uses Jackson and Woodstox for XML handling and the KotCot library for the handling of CoT messages in XML format.

Installation

The library can be installed from JitPack.

If you are using Gradle, add JitPack to the available repositories and then add KotTakCot to the dependencies of your project:

build.gradle:

...

repositories {
  ...
  maven { url 'https://jitpack.io' }
}

...

dependencies {
  ...
  implementation 'com.github.cyberpython:kottakcot:v1.0.1
  ...
}
...

If you are using Maven, update your pom.xml in a similar manner:

pom.xml:

...

<repositories>
  <repository>
      <id>jitpack.io</id>
      <url>https://jitpack.io</url>
  </repository>
</repositories>

...

<dependency>
    <groupId>com.github.cyberpython</groupId>
    <artifactId>kottakcot</artifactId>
    <version>v1.0.1</version>
</dependency>

...

Reading & writing TAK messages

TAK messages are comprised of a 3-byte header and the message's payload either in CoT XML or ProtoBuf format.

Reading a TAK message is quite straightforward:

// takBuffer contains the TAK message bytes including the 3-byte header:
val takCot = KotTakCot()
val evt = takCot.parse(takBuffer)

// evt now holds the CoT Event's data

From this point on you can use the KotCot library's Event object methods to access the CoT event's data.

Notice that there is no differentiation between parsing CoT XML and Protobuf-based messages.

Things to note is that:

• In order to acces the MILSTD-2525B SIDC symbol code embedded in the CoT Event's type field, you can use the CoTType2SIDC::to2525B method, passing the CoT Event's type as a parameter:

  val sidc = CoTType2SIDC().to2525B(evt.type)

• The detail field of the CoT Event and its sub-items can be accessed using dot-notation through the Event::getDetail method:

  val trackSpeed = evt.getDetail("track.speed")

  Attempting to access non-existing fields will result in an IllegalArgumentException.

Serializing an Event object to a TAK message is straightforward as well:

// Create the CoT Event object and a detail object for it:

val detail = new TakCotDetail(
  new TakCotContact("IAPETUS", "192.168.1.50:4242:tcp"), 
  new TakCotGroup("Green", "Team Lead"), 
  null, null, null, 
  new TakCotTrack(280.0, 60.0), 
  null);

val event = Event(Point(37.409, 23.768, 0.0, 0.0, 0.0), 
                  detail, // <--- detail
                  2, 
                  CoTType2SIDC().from2525B("SFGPUCVRA------"), "public", "1-r-c",
                  "4333319d-3430-44f3-bada-195fcc9bf349", 
                  ZonedDateTime.parse("2022-08-20T18:50:10Z"), 
                  ZonedDateTime.parse("2022-08-20T18:50:10Z"), 
                  ZonedDateTime.parse("2022-08-20T19:00:10Z"), "m-g")
// Write to XML:
val takCot = KotTakCot()
val msg = takCot.write(event)

Note: Use the TakCotDetail class to construct a compatible detail object. Note that no validation takes place for the contents of the detail.xmlDetail field (it may contain any XML-serializable value).

License

All code is licensed under GNU GPL v3 (required since the ATAK-CIV .proto files used to generate the TAK-compatible protobuf message-handling classes are licensed under the GNU GPL v3 license as part of ATAK-CIV's source code).