A Java Road Map

With everything that's going on, it's hard to keep track of what's available now, what's promised, and what has been around for some time. The following sections comprise a road map that imposes some order on Java's past, present, and future.

The Past: Java 1.0-Java 1.4

Java 1.0 provided the basic framework for Java development: the language itself plus packages that let you write applets and simple apps. Although 1.0 is officially obsolete, there are still a lot of applets in existence that conform to its API. Java 1.1 superseded 1.0, incorporating major improvements in the Abstract Window Toolkit (AWT) package (Java's original GUI facility), a new event pattern, new language facilities such as reflection and inner classes, and many other critical features. Java 1.1 is the version that was supported natively by most versions of Netscape and Microsoft Internet Explorer for many years. For various political reasons, the browser world was frozen in this condition for a long time. This version of Java is still considered a sort of baseline for applets, although even this will fall away as Microsoft drops support for Java in their platforms. Java 1.2, dubbed "Java 2" by Sun, was a major release in December 1998. It provided many improvements and additions, mainly in terms of the set of APIs that were bundled into the standard distributions. The most notable additions were the inclusion of the Swing GUI package as a core API and a new, full-fledged 2D drawing API. Swing is Java's advanced user interface toolkit with capabilities far exceeding the old AWT's. (Swing, AWT, and some other packages have been variously called the JFC, or Java Foundation Classes.) Java 1.2 also added a proper Collections API to Java. Java 1.3, released in early 2000, added minor features but was primarily focused on performance. With Version 1.3, Java got significantly faster on many platforms and Swing received many bug fixes. In this timeframe, Java enterprise APIs such as Servlets and Enterprise JavaBeans also matured. Java 1.4, released in 2002, integrated a major new set of APIs and many long-awaited features. This included language assertions, regular expressions, preferences and logging APIs, a new I/O system for high-volume apps, standard support for XML, fundamental improvements in AWT and Swing, and a greatly matured Java Servlets API for web apps.

The Present: Java 5.0

This tutorial includes all the latest and greatest improvements through the final release of Java 5.0. This release provides many important and long-awaited language syntax enhancements including generics, typesafe enumerations, the enhanced for-loop, variable argument lists, static imports, autoboxing and unboxing of primitives, as well as advanced metadata on classes. A new concurrency API provides powerful threading capabilities and APIs for formatted printing and parsing similar to those in C have been added. RMI has also been overhauled to eliminate the need for compiled stubs and skeletons. There are also major additions in the standard XML APIs. Here's a brief overview of the most important features of the current core Java API:



JDBC (Java Database Connectivity)

A general facility for interacting with databases (introduced in Java 1.1).



RMI (Remote Method Invocation)

Java's distributed objects system. RMI lets you call methods on objects hosted by a server running somewhere else on the network (introduced in Java 1.1).



Java Security

A facility for controlling access to system resources, combined with a uniform interface to cryptography. Java Security is the basis for signed classes, which were discussed earlier.



JFC (Java Foundation Classes)

A catch-all for a number of features, including the Swing user interface components; "pluggable look and feel," which means the ability of the user interface to adapt itself to the look and feel of the platform you're using; drag and drop; and accessibility, which means the ability to integrate with special software and hardware for people with disabilities.



Java 2D

Part of JFC; enables high-quality graphics, font manipulation, and printing.



Internationalization

The ability to write programs that adapt themselves to the language the user wants to use; the program automatically displays text in the appropriate language (introduced in Java 1.1).



JNDI (Java Naming and Directory Interface)

A general service for looking up resources. JNDI unifies access to directory services, such as LDAP, Novell's NDS, and others.

The following "standard extension" APIs aren't necessarily part of the core Java distribution; you may have to download them separately:



JavaMail

A uniform API for writing email software.



Java 3D

A facility for developing apps with 3D graphics.



Java Media

Another catch-all that includes Java 2D, Java 3D, the Java Media Framework (a framework for coordinating the display of many different kinds of media), Java Speech (for speech recognition and synthesis), Java Sound (high-quality audio), Java TV (for interactive television and similar apps), and others.



Java Servlets

A facility that lets you write server-side web apps in Java.



Java Cryptography

Actual implementations of cryptographic algorithms. (This package was separated from Java Security for legal reasons.)



JavaHelp

A facility for writing help systems and incorporating them in Java programs.



Enterprise JavaBeans

A component architecture for building distributed server-side apps.



Jini

An interesting distributed component technology that is designed to enable distributed computing, discovery, and rendezvous of devices ranging from software tools to hardware and household appliances.



XML/XSL

Tools for creating and manipulating XML documents, validating them, mapping them to and from Java objects, and transforming them with stylesheets.

In this tutorial, we'll try to give you a taste of as many features as possible; unfortunately for us (but fortunately for Java software developers), the Java environment has become so rich that it's impossible to cover everything in a single tutorial.

The Future

Java shows no signs of slowing down and there are many areas where the growth of new technologies is now synonymous with the growth of the Java implementations of those technologies. This is especially true in the areas of web services, web app frameworks, and XML tools. Java continues to expand its role in web-based and server-side enterprise apps. What's old is also new again, and client-side Java is gaining momentum as well. There are now more desktop Java apps being used on a daily basis than ever before. The area of small devices continues to be a rich one for Java. The Java "Java 2 Micro version" or J2ME is a subset of Java designed to fit on devices with limited capabilities. The reference platform for the J2ME architecture is the Palm PDA. Java is also now shipping in many cell phones, allowing downloadable apps and media. Probably the most exciting areas of change in Java today are found in the trend toward lighter weight, simpler frameworks for business and the integration of the Java platform with dynamic languages for scripting web pages and extensions. There is much more interesting work to come.

Availability

You have several choices for Java development environments and runtime systems. Sun's Java development kit (JDK) is available for Windows and Linux and ships as standard equipment with Mac OS X and Solaris. Visit Sun's Java web site at http://java.oracle.com for more information about obtaining the latest JDK (Version 5.0 is included on the accompanying CD-ROM; view CD content online at http://examples.oracle.com/learnjava3/CD-ROM/). There are also Java ports for other platforms, including NetWare, HP-UX, OSF/1 (including Digital Unix), Silicon Graphics's IRIX, and various IBM operating systems (including AIX, OS/2, OS/390, and OS/400). There are also a whole array of popular Java Integrated Development Environments. We'll discuss two in this tutorial: IBM's Eclipse (http://eclipse.org) and the Sun-backed NetBeans IDE (http://netbeans.org). These all-in-one development environments let you write, test, and package software with advanced tools at your fingertips. As for Java applets in web browsers, the world is generally too muddled to catalog specific versions of Java available on specific platforms. The answer, as we'll discuss later in this tutorial, is to use the Java Plug-in in your pages, which adds up-to-date Java support for all browsers. With that said, the latest versions of the Netscape, FireFox, and Safari browsers generally do come with up-to-date Java runtimes. It is mainly Microsoft Internet Explorer that is the outlier.

Comments