Using the Web and Jini to link Vending Machines and Enterprise Systems

Overview

• Jini
• SAP
• Inventory systems
• Coke machines
• Vending machines and O/O
• Vending machines and Jini services
• Vending machines and Jini clients
• Summary

Jini

• New distributed object technology from Sun Microsystems
• Built entirely in Java
• Allows hardware and software services to advertise their presence
• Uses type-safe object matching system, not weak string matching like naming services
• Clients can search for and select services
• Clients and services can broadcast events to listeners

SAP

• Typical Enterprise Resource Planning systems
• Designed to deal with large business information systems
• Typical application areas are
  • E- and M-commerce
  • Customer Relationship Management
  • Supply Chain management
  • Financials or Human Ressources
• mySAP.com makes access to SAP systems available by Web URLs

Inventory systems

• An inventory system stores a number of attributes for each material in the database:
  • Material
  • Location
• The inventory information for a material is altered by methods such as:
  • A GoodsMovementType such as ADD or REMOVE
  • A Quantity
  • A Cost Center
• A SAP inventory system allows changes to be made by accessing a URL of the form

        http://sap_host/GoodsMvt?GM_CODE=ADD&
                    MATERIAL=Coke&STGE_LOC=4352&
                    COST_CENTER=345
        

Coke machines

• Vending machines are everywhere
• Typically unconnected to Internet, but this is changing
• Keeping track of vending machine state is a manual process
• Consequences:
  • Machines run out of goods
  • Breakdowns are not detected quickly
  • Refillers have to carry extra stock to each machine
  • Feeding results into inventory system is a manual process

Vending machines and O/O

• A vending machine is a container of items that can belong to an inventory system
• This involves two Java interfaces

  public interface InventoryItem {
   
      String getMaterial();
  } // InventoryItem
       

• and

  public interface InventoryItemContainer  {
   
      public final long ADD_ITEM = 1;
      public final long REMOVE_ITEM = 2;
   
      public int getStorageLocation()
          throws java.rmi.RemoteException;
   
      public void add(InventoryItem item)
          throws java.rmi.RemoteException;
   
      public InventoryItem remove()
          throws java.rmi.RemoteException;
  } // InventoryItemContainer
        

Vending machines and Jini services

• A vending machine can be a Jini service that can advertise its presence on the internet
• The vending machine maintains state information about its contents
• The vending machine is aware of when its state changes
• The vending machine can broadcast state change events when items are added or removed

Vending machines and Jini clients

• A Jini client can locate vending machines
• The client can add itself as a listener for events
• The client will be informed each time an item is added or removed from a vending machine
• The client can perform actions specific to an inventory system, such as making an HTTP request to a mySAP.com inventory system
• Service broadcasting of events is independent to client handling of events
• Services can be completely generic, clients are specific to inventory systems

Demonstration

• Cannot do this live
• Emulated coke machine running at the Convention Center in Brisbane for SAPphire conference
• Client on DSTC machine at Queensland University
• SAP inventory system in Karlsruhe, Germany

Conclusion

• Jini allows adapters to be built between software and hardware systems
• Manual processes can be automated
• Better business knowledge of previously manual systems
• Still to do:
  • Industry standardisation of machines and d/b systems as Java business objects
  • Issues of networking and security
  • Identification of similar opportunities