Java Hello World

For the purposes of this exercise, the program instance you create will:

  • Register itself to the Linxter ISB
  • Retrieve its configuration settings
  • Activate itself
  • Create a communication channel request to itself and automatically accept it
  • Send a message (to itself)
  • Receive a message back from the ISB
  1. You will need to download the Linxter SDK before you can begin this section. You will also need to download the Hello World project.
  2. Next you will need to download the preconfigured database file for your program, as well as copy your program's Activity ID (assigned when you registered it to the ISB).
  3. Open Eclipse
  4. Import the Hello World project you downloaded (File - Import - Existing Projects into Workspace).
  5. You will now need to add the Linxter SDK (linxter-java.jar) to your project. In the Package Explorer view, right click on lib and select Import - From File System. Browse to the folder you stored it in and select it.
  6. Add the preconfigured database file (linxtersdkdb.db) to your program. Right click on the Hello World project and select Import - From File System. Browse to the folder you stored it in and select it.
  7. You will now need to open the HelloWorld.java in the project source and replace the ActivityId string value with the Activity ID assigned to your program when you registered it to the ISB.

  8. You are now ready to run your Hello World program.

    Sending and Receiving Messages

    Scheduled sending and receiving are automatically enabled when instances of your program are running. All of the timing code for the scheduled sending and receiving is taken care of for you within the SDK. The settings for these events can be dynamically updated through Web Manager. Sending and receving messages is asynchronous and non-blocking to your program. This means your program instance can keep on doing what it is doing and not worry about getting hung while processing a send or receive operation.

    Optional: In your code, you can also send and receive on-demand using the SendNow() and ReceiveNow() method calls.

  9. When your program instance receives a message back from the ISB, it will display the message that was sent to it.
  10. That’s it! You have now created your first Linxter enabled program, and sent and received a message over a secure, reliable, dynamic communication channel.
  11. When you run your program again, it will be faster because it does not need to register itself onto the Linxter ISB and retrieve its settings.