The following excerpt is from "Inside Java WorkShop," by Lynn Weaver & Bob Jervis. Sun Microsystems Press/Prentice Hall PTR book. (ISBN 0-13-858234-3; $39.95US) Copyright Sun Microsystems Inc., 1997.

With the release of the Java 1.1 API, Java developers have even more tools to work with. Two important abilities that were added to the Java 1.1 API include the Java Database Connectivity (JDBC) objects and objects to handle Serialization. JDBC provides developers with the means to connect to any type of database and perform queries and updates against the data located in the database. The JDBC API finally gives developers the ability to create usable business solutions using Java. Another new ability added to the Java language is the ability to use Serialization. Serialization is the process by which the application can send program objects through a stream, which can be a file stream or a network stream. Sending objects through a stream will allow developers to create solutions that were not available until now.

Almost every working professional has experienced the tedium and frustration that results from scheduling a meeting for multiple attendees with potentially conflicting schedules plus additional constraints imposed by the meeting rooms and other resources. This problem deserves serious attention as many people in typical organizations have to spend a large portion of their working time in scheduling and attending meetings. With autonomous agents [1], which can schedule meetings and manage calendars on behalf of their users, the savings in time and effort can be tremendous. Users can then be relieved for more creative and productive tasks.

Introduction In the first article of this series, we compared how Java and C++ support various object-oriented concepts. In this second and final part, we cover other programming language concepts and examine differences in how the two languages support them. Each programming language concept has its own section, first presenting the concept in commonly-used terms and then comparing how ANSI C++ and Java 1.0 implement, or can be used to implement, it.

Welcome to Java Foundations! Java is purported, by its designers, to be a "simple" programming language. While reasonable arguments can be made that illustrate Java's simplicity in comparison to a language like C++, developers coming from languages such as the xBASE derivatives, Visual Basic or PowerBuilder, will probably not agree that Java is simple at all. To fully exploit the power of Java, you need to understand and apply the principles of object-oriented analysis, design and programming. You need to learn the nearly 150 classes that comprise the core Java class libraries. You need to have at least a basic understanding of distributed software component models such as CORBA and COM/OLE/ACTIVEX. To develop network and Internet applications you need to understand client/server principles, sockets, URLs, etc. In short, regardless of what some publishers may imply, Java is not a programming language for "dummies" or "idiots". Nor will the average programmer be more than marginally proficient in Java after 21 days of experience.

One of the most significant aspects of Java programming is that it creates applications that have extraordinary relevance to computer security. Few UNIX administrators would be prepared to allow millions of users to execute programs as root (the administrative superuser) on their system, yet this level of potentially total power is what every user cedes when they point their browser at a URL containing some form of Java executable. Because of this, knowledge of computer security is becoming a requirement for Java programmers, and Java developers are being held accountable for the security implications of their code. Java experts who can speak authoritatively on security issues will be in greater demand.

Introduction Much of the excitement about Java comes from C++ programmers looking for a better way to develop software. In this article we take an in-depth look at Java from the perspective of a C++ expert who wishes to quickly come up to speed and transfer hard-earned knowledge of C++ to the new language.

Ever since it was announced in May of 1996, Java Beans has been a topic of great interest among Java developers. The first generation Java technology embodied several modern software engineering concepts such as object-orientation, platform independence, multithreading, network awareness, etc. However, it lacked a few important elements, including support for visual assembly of software components, object persistence and distributed computing. Java Beans is the next generation Java technology that not only adds the functionality it lacked but also makes Java programs more portable and interoperable with a number of component models that include Microsoft's ActiveX/COM, Netscapes's LiveConnect and IBM's OpenDoc.

Introduction Large-scale distributed applications and shells often require the execution of external modules. Because the modules are not known at compilation time, this execution must be dynamic. For example, upon entering a command at the UNIX prompt, the shell must find, load, and execute the requested program or application. Although several methods have been found for loading (and executing) dynamic Java classes, launching a Java Application from within another Java program (applet or application) remains a difficult task.

Last month, we began looking at building data structures in Java. The idea for the article was inspired by the constant posts to comp.lang.java from people who were lost without pointers. The data structures which we introduced were useful, but were really more of a starting point for some more advanced data structures. The third data structure covered last month was a binary search tree. As you will remember, binary search trees are great for storing large amounts of information, as search time is much faster than for a linked-list. The problem with binary trees, however, is the worst case scenario. When the input stream is already in order (reverse or forward), then our binary tree becomes a simple linked list. This, of course, can bring our worst search time from O(lgN) all the way down to O(N) which is no good when you have to search large amounts of data.

Java applets can be used to provide better dynamic interaction with the user on Web pages than simple CGI scripts and html forms. However, like any programming language, the code does not spring forth perfect, but rather is designed, implemented, and then debugged.

But an equally compelling story can be told about the virtues of building the server-side of a web application in Java as well. This article will outline the major design issues of creating a server-side Java solution, and though I promise not to make this an infomercial, a number of examples will be drawn from one particular implementation, a commercial product called Dynamo which I played a key role in creating.

Introduction Scriptic is an experimental extension to the Java language. Why is this new language on top on another brand new one? What problems does it solve?

Java programs can be classified as either Java applications or Java applets, based on the modules' execution content. While applets require the presence of a Java-enabled browser (or an AppletViewer), applications are designed to run on the client machine on the top of the Java interpreter, without the need for special helper applications.

A common occurrence on comp.lang. java is a post questioning the ability to create growable data structures in Java. The common belief tends to be that pointers are necessary to implement a growable data structure. This obviously stems from experience with languages like C or Pascal, where one is forced to manipulate pointers to track memory in growable data structures. If you think about the data structures, however, all that is really necessary to implement these systems is the ability to dynamically allocate memory. Dynamic memory allocation, a fundamental part of any modern programming language, is actually much easier to handle in Java than in C or Pascal. This is obviously due, in part, to Java's automatic garbage collection. Not only does Java provide for easier memory management, but it also provides several useful classes and interfaces which aid in the creation of data structures. This month's General Java column will cover creation of stacks, queues, and trees in Java.

Introduction Computing in scientific and engineering areas often deals with manipulating numbers that represent physical entities, such as durations, weights, and forces. A common source of errors in scientific computing involves processing numbers that represent different kinds of entities, or that are related to different units, and utilizing the result for additional computation. A number is referred to as dimensioned when it relates to a specific entity such as distance, time, or temperature, and the number implies a particular unit of measure. A dimensionless number, also known as a nondimensional parameter, is a ratio of physical properties and conditions of such a nature that the resulting number has no defining unit of weight, duration, and so on.

Native methods are functions written in C or C++, compiled into a library, and dynamically loaded by the Java runtime. This article describes how Java programs can call native methods, and how native C code can create Java objects and invoke Java methods. The examples are written for Windows 95, Windows NT and Solaris, and should be portable to other platforms.

When Sun Microsystems introduced the Java language, professional software engineering and network programming was forever changed. Java's language-level support for platform-independent software development, multithreaded applications, true object-oriented program design, and dynamic class loading have proven to be great tools for fast and inexpensive software prototype design.

Preface Current difficulties in developing and maintaining software within limited budgets and challenging development-schedule constraints result in part from the shortcomings of existing programming languages and development environments. In the context of distributed programming for the World Wide Web, Sun Microsystems has recently introduced the Java programming language environment. Since formal announcement of Java in May of 1995, a number of companies have already signed agreements to license Sun's technology. Among these new partners are Netscape and Oracle.