As/400E Advanced Technology; Java - IBM AS/400e User Handbook Manual

AS/400e Advanced Technology

AS/400e Advanced Technology
The AS/400e offers important advanced capabilities in such key areas as Java, Web serving,
Lotus Domino, integration with Windows NT, managed availability, database, and Business
Intelligence solutions. The AS/400e also continues to be a strong performer in such growing
areas as data warehousing and the Internet. To gain an appreciation of these technologies on
the AS/400e and of the particular strength of the AS/400e in delivering them, this chapter
provides a summary of each of the application segments mentioned above.

Java

Java is a key application development environment for the AS/400e. As Java technology
evolves from Sun, the AS/400e system takes advantage of the new functions and features of
this environment.
There is an exciting future for Java on the AS/400e. The AS/400 Developer Kit for Java
supports Sun's Java 2. With the concurrent Java support shipped as part of the V4R4 AS/400
Developer Kit for Java, you can install Java 2 on systems where JDK 1.1.6 or 1.17 are already
installed. A Java Virtual Machine, which resides below the Technology Independent Machine
Interface (TIMI), enables fast interpretation and execution of Java code on the AS/400e. In
addition, a type of static compiler is available called a class transformer , which generates
RISC machine code from Java byte codes. This Java transformer enables the direct execution
of Java on the AS/400e without the overhead of interpretation.
High-performance Garbage Collection is provided by OS/400 to improve the performance and
the scalability of Java. An advanced Garbage Collection algorithm allows Java to scale to the
large numbers of objects expected when running enterprise applications on the server. Over
time, Java is planned to become even more integrated with, and tuned for, OS/400 to meet
the requirements of performance and scalability on the server without compromising the
cross-platform portability of the rich language.
Other technology included in the AS/400 Developer Kit for Java allows GUI applications to run
on the AS/400 system without modification. This support is called Remote Abstract
Windowing Toolkit (AWT). It intercepts GUI requests coming from a Java program and
re-routes the requests to an attached workstation running its own Java Virtual Machine
(JVM). The workstation then interprets and displays the java.awt graphical components. This
allows server programs that have graphical interfaces for configuration or tuning to run on the
AS/400 system without modification.
The OS/400 unique single-level-store architecture is also exploited to give Java objects on
the AS/400e an advantage over other platforms. Java objects on the AS/400e system can be
full-fledged system objects allowing them to be persistent, shared, secure, backed up, and
restored. This allows the AS/400e to offer persistent Java objects with exceptional
39
© Copyright IBM Corp. 2000