Livespaces
Training Workshop - Entities Exercise

Exercise 2: Entities

By the end of this exercise you will:

• Know how to create Entities
• See how to hook into Elvin and find or create a RoomEntity
• Know how to use synchronisation when changing Entity values
• Know how to use ec to watch the Livespace events

Files involved:

• project livespace.services.example
  • package livespace.workshop.examples
    • Hobbit.java
    • HobbitServer.java
    • HobbitFinder1.java
    • HobbitFinder2.java
    • HobbitFinder3.java
    • SpeechListener.java
    • TrainingUtils.java

Run targets:

• HobbitServer
• Livespace Browser App (localhost)
• HobbitFinder1
• HobbitFinder2
• HobbitFinder3

Steps:

1. Run the local elvin daemon
2. Open a cygwin shell
3. Run the Elvin consumer tool ec and listen for Livespace events with the command:

   ec -e elvin://localhost "require(Livespace-Protocol)"

4. Open Eclipse from the desktop shortcut
5. Look at Hobbit.java and note the boilerplate code
   • constructors
   • ENTITY_TYPE constant
   • getType() method
6. Look at HobbitServer.java
   • main() method
     • Finding the Elvin connection
     • Finding or creating the local RoomEntity
     • Creating a server
     • Cleaning up resources
   • constructor
     • Creating the Hobbit Entity
     • Creating the EntityRegistry and adding listeners
     • Creating the EntityServer
   • dispose() method
   • Running the server using a different Hobbit name.
7. Run the Livespace Browser Application pointed at the localhost
   • Play with Hobbit properties
8. Look at a basic client
   • HobbitFinder1.java
     • Finding the Elvin connection
     • Finding the local Room
     • Clean up
   • HobbitFinder2.java
     • Find our Hobbit
   • HobbitFinder3.java
     • Make changes to our Hobbit
     • Note use of synchronisation
9. Run the HobbitServer but pointing it to ics-linux as the host.
   • Change the name of your hobbit (first command line argument)
   • Use the -Dlivespace.elvin=elvin://ics-linux command line switch to use ics-linux
10. Use the Service Browser from your Livespace Dashboard to manipulate all the Hobbits.
11. Questions