| There is a wired
world of computers that use J2EE and CORBA as the underlying technology to
communicate and network. Then again, there is the rapidly changing wireless
world. It is no surprise that these two worlds are very dissimilar and diverse
and it is the intention of this project to bring them together. For the
plethora of different devices that make up the wireless world, CLDC, MIDP, CDC;
Java comes in multitude of flavors. In equipment where memory restriction is
severe, often just hundreds of kilobytes, Java is available in a low
denominator configuration. In equipment where memory and color LCDs are
available in greater abundance, Java comes with lesser impositions. It is not
always about memory; sometimes restrictions on networking and communications
tend to segregate them as very distinctive devices. Like memory, means of
communication may vary largely among these little devices; some communicate
through http protocols, many through TCP/IP, or just Infrared, Serial Port.
This project uses a small IIOP engine on these devices to make the call. In a
typical peer to peer communication between client and server in J2EE or CORBA
environment, the server process normally has a single listener (typically a
port). Extending the Server Engine to multiple protocol listeners is the main
design theme. There could be multiple approaches to a problem of this nature.
One such approach would be to obtain an XML or soap envelope containing all
available Objects, their methods, return values and arguments to the methods.
The request could consist of getting an XML with interface, method, return
values and types, argument types, names and values. A better idea would be to
send a Stringified Object Reference which after parsing; simultaneous requests
could be sent to the CORBA servers. This approach uses a very thin client for
http or xsl / xml or soap / xml handling. The interface, methods and arguments
are passed as data types. The clients could be Spotlets, Midlets, HTML forms,
or Simple AWT forms as permitted by the VM on different devices with different
operating systems. Many of these devices run on intermittent network
connections. Unlike a Web Browser, session management is extremely tricky and
has addressed in the next part of this whitepaper. Therefore for most part
connections are established during request and released at response. Wireless
and Small Devices implementations normally support the Http Connection
interface, which allows application to be portable across different mobile
information devices by using HTTP as the underlying protocol. HTTP in spite of
obvious advantages is still a request-response system and is therefore quite
stateless. Besides, HTTP implementation may not always occur over TCP/IP
connections. Many of these devices do not use TCP/IP to communicate. This
leaves little to imagination the state of an ORB or a J2EE client on these
devices. This project uses a small IIOP engine on these devices to make the
call. XML and SOAP are already contesting the IIOP protocols. This project is
intended to diminish some of the drawbacks of IIOP on Mobile devices through
HTTP and XML piggybacks. emiiop is hosted by:
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