- Java is now more dynamic. An expanded Class class, in conjunction with the new java.lang.reflect package, allows objects to access methods and variables of objects that they were not compiled with.
- There are classes in java.io that build on the new dynamic capabilities to provide the ability to read and write objects as streams of bytes.
- There is increased support for internationalization. The support includes a Locale class and classes to format and parse data in locale-specific ways. There is also support for loading external locale-specific resources, such as textual strings.
- The java.util.zip package provides the ability to read and write compressed files.
- The java.math package provides the ability to perform arithmetic operations to any degree of precision that is necessary.
There are also more ways to package and distribute Java programs. In addition to being able to build command-line based applications and applets that are hosted by browsers, we now have the Java Servelet API that allows Java programs to function as part of a web server. Furthermore, the nature of applets may be changing. Instead of waiting for large applet to be downloaded by a browser, we now have push technologies such as Marimba's Castanet that ensure that the most current version of an applet is already on our machine when we want to run it.
Many new uses for Java have appeared or are on the horizon. For example, NASA is using Java applets to monitor telemetry data, instead of building more large, dedicated hardware consoles. Cellular phone manufacturers have committed to making cellular phone models that support Java, so in the future we may see Java programs that run on cellular phones and allow us to check e-mail or view location maps. Many additional APIs are also on the way, from Sun and other companies. These APIs not only supply infrastructure, but also provide frameworks for building domain-specific applications, in such areas as electronic commerce and manufacturing.
This java ebook is about the classes that provide the most fundamental infrastructure for Java. As you use this book, we hope that you will share our enthusiasm for the richness of what is provided and the anticipation of what is yet to come.