Chapter One

Chapter Two

Chapter Three

Chapter Four

Chapter Five

Chapter Six

Chapter Seven

Appendix

Java Computing in the
Enterprise Whitepaper
(Postscript Compressed
141KB)

Java Computing in the
Enterprise Whitepaper
(Acrobat 124KB)

The primary focus of this white paper is to describe the use and benefits of Java in enterprise computing environments. A short description of Java is presented here. For more, see "http://java.sun.com/doc/general.html."

In brief, Java is an application development platform providing a portable, interpreted, high-performance, simple and object-oriented programming language and run-time environment.

Characteristics associated with Java include:

• Applications are much more secure than schemes running native code because the Java run-time system (part of the Java Virtual Machine) inspects all code for viruses and tampering before running it.
• Applications are adaptable to changing environments because users dynamically download application code from anywhere on the network.
• Shortened application development and deployment through code reuse, easier testing and rapid deployment via intranet.
• Portability across computing platforms because the Java Virtual Machine is available on all systems.
• Applications are fast because today's processors can provide efficient virtual machine execution. JIT (just-in-time) compilation and direct Java execution in silicon can deliver even more performance.
• Simple to learn and use with component-level object programming.
• Graphical applications and GUI functions are high performance because of Java's built-in multithreading.
• Robustness because the Java run-time system manages memory. (Memory management errors are a major bug source in traditional software.)

The essence of Java Computing is a client/server model in which Java application code is dynamically downloaded from server to client on-demand. In some cases, the applications are stored in cache on a hard disk at the client location and in others, they are stored only in DRAM. Since applications normally reside on the server and are delivered only as needed, all administration can focus centrally on the server, and users are assured of access to the latest application release level.

Java applications can run anywhere the Java Virtual Machine software is installed. Thus, they can run in any Java-enabled browser (e.g., Netscape Navigator or Internet Explorer). This is a key feature that allows a gradual migration to a simpler-to-manage client -- a Java device. This is a desktop client machine that is connected to the network and can download and run any Java application, but is free of the complexity and client administration needs of a traditional PC.

Rather than a traditional OS, the Java device contains a simple Java OS with a Java Virtual Machine. The Java OS and Java Virtual Machine can be stored at the client in flash ROM or can be booted from the network. Client data storage is done centrally on a file server or servers, and all client administration and configuration control is accomplished centrally.

Applications running on the client communicate with servers via standard network protocols. A Java client may open a standard TCP/IP socket connection with an application server. Alternatively, more sophisticated client-server protocols can be employed. The JDBC (Java Database Connectivity) protocol provides SQL-oriented connectivity to databases. More complex, three-tiered applications can be built using distributed objects with industry-standard CORBA protocols. Three-tiered or multi-tiered application models are the key to leveraging existing back-end systems.

Since Java is truly platform independent, Java Computing spans much more than traditional desktop environments. Java clients will include "smart" telephones with built in displays, PDA-like devices, set-top boxes, kiosks, point-of-sale devices, and even home video game machines, to name a few. Sun has licensed Java for use in all of these devices. They represent potential Java-enabled channels to customers and consumers for the services and interactions delivered beyond the firewall on the Internet. Java Computing gives companies an architecture that leverages their enterprise computing investment across all of these emerging channels.

More technical information on Java can be found in "The Java Language Environment White Paper," by James Gosling and Henry McGilton, May 1996, available at "http://java.sun.com/doc/white_papers.html." Additional information for developers can be found at the "http://java.sun.com" web site.