ION Java Architecture

Figure 2-1: ION Java Architecture

Figure 2-1: ION Java Architecture

ION Server

The ION Server is a program that manages communication between an ION client application (either a Java Applet running in a Web browser or a stand-alone Java application) and IDL. The ION Server translates requests from ION clients into commands that can be processed by IDL, and then passes output from IDL back to the client for display. The ION Server is discussed in detail in Configuring ION Java.

Once the incoming client has been verified by the ION Daemon, the ION Daemon starts an ION Server process and connects the client with the ION Server process. The ION Server process checks out an ION license and then begins command processing. The ION Server process is responsible for the following:

Reading requests from the ION client,

Performing security checks on the client request,

Executing valid ION/IDL commands,

Sending graphic information and data to the ION client.

Security Checks

Once a command is received from the client, the request is passed through the ION security system. Any security failure causes the command to be logged and an error condition to be sent to the client. If the command passes the security system, it is passed to IDL for execution.

Command Execution

When a command is executed, all graphic and command log information is sent to the client. Once the command is completed the error status is sent to the client and the ION Server process waits for the next request.

ION Daemon

The ION Daemon is a program that makes the initial connection between an ION client and the ION Server. The ION Daemon "watches" a specific port on the ION Server's host computer. When the daemon receives a request for connection, it performs basic security screening before connecting the ION client to the ION Server. The ION Daemon is discussed in detail in Configuring ION Java.

Parsing command line parameters

Establishing the security level and initializing security levels

Maintaining server logs

Managing the number of current connections

Receiving connections and starting ION Server processes

Verifying incoming requests as valid ION clients

Pre-Built ION Client Applets

The ION package includes a set of pre-built Java applets. The pre-built applets allow you to begin using ION immediately, without the need to write Java code. See Using ION's Pre-Built Applets for details.

ION Component Classes

The ION Component classes provide a simple, straightforward interface that allows you to create ION client applets and applications quickly and easily. While using the ION Component classes does require that you write Java code, the classes handle most of the details of writing applications to interact with IDL seamlessly. See Overview of the ION Java Classes for details.

ION Low-Level Classes

The ION low-level classes are the backbone of the ION Java system; they provide the tools a professional Java programmer needs to create robust applications to interact with IDL. The ION Component classes and the ION pre-built applets are both built directly from the ION low-level classes. See ION Low-Level Classes for details.