For Starters: #6. Java? ActiveX? Getting to Know All About Both of You

---

Mary Haggard
Program Manager
Microsoft Corporation

May 23, 1997

The following article was originally published in Site Builder Magazine (now known as MSDN Online Voices).

All of us remember the first time we visited a World Wide Web site where we did something besides read text and click hyperlinks. Remember seeing a gray screen, and having your browser status bar say "Java Applet initializing?" How when it finally came in, it really wasn't that great? Or the first time the ActiveX authentication screen popped up on your browser?

Those were the good old days. Now you're wiser (and older), and you understand that when you go to an interactive Web site, chances are you'll interact with a component written as either ActiveX™ or Java™. This time, we're going to talk about what ActiveX and Java are, some of the pros and cons of each, and the tools available to develop in each.

ActiveX

Just when you had read the last page of Kraig Brockschmidt's opus on object programming, Inside OLE, Microsoft went and changed the way we think about objects. We stopped talking about OLE and suddenly started using terms like "ActiveX" and "components." You thought you learned the basics for nothing, right?

Wrong. ActiveX technology from Microsoft uses the Component Object Model (COM) and Distributed COM (DCOM) standards, allowing you to build and use components that enable interactive content for the World Wide Web. ActiveX objects and components are self-contained code that can be built to execute on both client and server machines. If you understand COM and DCOM, you understand ActiveX. Through ActiveX, Web sites use multimedia effects, interactive objects, and sophisticated applications to create an interactive user experience.

Server-side components used by Active Server Pages (ASP) technology are automation servers with no user interface. You can create your own automation servers with most of the tools used to create ActiveX controls. When activated, automation servers generate an HTML stream that is returned to the client's browser. Automation servers can automate access to a database, perform complex queries, and deal with data values for use by script code. Using Active Server Pages is an easy way to talk to server-side components via high-level script language. Nancy Cluts introduces experienced developers to the technology in An ASP You Can Grasp, and the MSDN Online Web Workshop has a great article on the how and why of developing server-side components.

I always try to make things simpler for you, but the truth is that both ActiveX and Java have great benefits and tradeoffs. You should consider these when making decisions on which technology to use.

Here's some thoughts on ActiveX:

Pros

• ActiveX components are downloaded to the user's system just once. They register themselves in the Windows Registry and can then be used many times by many Web sites to give users a great experience. (For instance, the menu control used here on the MSDN Online site can be found on many Microsoft sites, but you only need to download it once.)
• Familiar tools can be used to develop ActiveX: Visual Basic®, Visual C++®, and Borland® Delphi® are a few.
• Many vendors are now building ActiveX controls and components -- the same way many build VBX and OCXs -- so you may not need to develop a control yourself.
• The list of standards supported by ActiveX technologies is growing, and includes HTML, TCP/IP, Java, and COM.
• Multimedia on Web sites will improve, thanks to a great set of multimedia controls from Microsoft that will be available with Internet Explorer 4.0. A demo of one of those controls is available in the MSDN Online Downloads area.
• You can extend Java with ActiveX to enable Java applets to take advantage of audio and video controls, enhanced performance, printing, and other operating-system-level features.
• You can call ActiveX controls from any other OLE-aware application, so ActiveX functionality is not limited to the browser.

Cons

• Although ActiveX controls are extremely small to download, almost all controls require a run-time library (i.e., msvcrt.dll) to complete their functionality. Luckily, those libraries are included in many Microsoft applications and operating systems. The newest run-time library is the Visual Basic 5.0 run-time library (which was downloaded to your machine through the MSDN Online setup procedure). Soon, no download will be necessary; it will be included in Internet Explorer 4.0 and all future operating-system upgrades from Microsoft.
• Internet Explorer is currently the only browser that makes wide use of ActiveX technology (although a plug-in from NCompass Labs, called ScriptActive, allows Netscape Navigator to access ActiveX controls).
• Because of its architecture, ActiveX has become the focus of some Internet security concerns. So, too, has Java (see below).
• Watch for performance degradation. Be sure that the functionality you implement is worth any performance hit you will take. Test carefully, and keep trying different options. Since this is new technology, and there are so many differences between systems, there is no easy performance answer.

Java

Java applets also provide interactive functionality within a Web site. In very simple terms, an applet is a scaled-down version of a full Java application, and it runs inside a Java virtual machine (VM) that is implemented as part of a Web browser. The Java language is object-oriented and facilitates quick development. Many vendors provide great tools to develop Java applets and applications.

These days, anyone who tackles Java pros and cons opens themselves up. I decided to keep this list pretty short and sweet -- and as non-controversial as possible.

Pros

• Any version of Java code is cross-platform as long as a Java VM that supports all of the extensions used in the source code is installed on the user's machine.
• Many tools are available to develop Java code - including Microsoft Visual J++™.
• Many vendors are building Java applets, so you may be able to license or buy the functionality you need.
• Applets are limited by their security model to running inside a browser.
• Recent speed enhancements are lowering concerns about Java performance. However, test carefully, and again, keep trying different options.

Cons

• Because any version of Java code requires presence of a Java VM that supports all extensions used in the source code, you will have to test your applet on all available platforms to ensure that it works everywhere.
• Java applets don't register themselves with the operating system, so they need to be downloaded each time a user accesses the page.
• Java applets don't have much flexibility, and often need to be recompiled to change relatively trivial options.
• Security concerns have also been raised about Java.

Tools for Developing Components

The following information introduces you to the tools available from Microsoft for component and Java development. Use the links provided to learn more.

Visual Basic

Visual Basic and the Control Creation Edition can create controls from scratch, can write directly to the Win32 API, and can build composite controls - combining multiple controls into one package.Visual Basic 5.0 offers design-time debugging and opens the door to ActiveX development for millions of Visual Basic programmers. Note that the Visual Basic 5.0 run-time library is required for controls developed in Visual Basic, but the controlsize is amazingly small. The Visual Basic site has more information.

MFC

The Microsoft Foundation Classes (MFC) also offer a quick way for the C++ developer to create controls. MFC is one of the development tools within Microsoft Visual C++ . Control developers need stay within the realm of MFC, as development work outside of those parameters can be challenging.

Visual J++

Microsoft offers the Visual J++ version 1.1 professional development tool for Java. It includes a fast Java compiler, integrated debugging, an integrated development environment (IDE), and a collection of integrated components to create, test, tune, and deploy Java code on multiple platforms.

Microsoft SDK for Java.

The Microsoft software development kit (SDK) for Java , version 2.0, gives developers tools, class libraries, sample code, and full documentation for creating Java applications. This new version adds the latest edition of the Java VM for Windows, a preview release for developers of the AFC GUI Libraries, a Script Debugger for debugging Java in the context of complex Web pages, Windows NT Service support, and CAB file tools for rapid and secure delivery of Java applications.

ActiveX Template Library

These C++ templates allow for development of ActiveX controls and other types of components, including Windows NT service objects. ATL development requires at least Visual C++ version 4.2b, and can be downloaded from the Visual C++ Web site. It provides minimal wizard support, small size and fast execution, self-sufficient controls. To use ATL, you must have an understanding of OLE and COM.

ActiveX SDK

The Microsoft ActiveX SDK includes a variety of technologies introduced by Microsoft to facilitate development of Internet applications and content, including tools and information to aid in the development of ActiveX controls.

Online Resources

• See Microsoft's Java implementation site.
• Check out Microsoft Visual Tools for information about Visual C++, Visual Basic, and other tools.
• Microsoft Developer Network is Microsoft's complete developer resource.
• Gamelan  has great Java applets, tool vendors, and more.
• ACTIVEX.COM  can link you to ActiveX controls and other software, as well as to information and resources for programmers and developers.
• The MSDN Online Web Workshop has SDKs, whitepapers, and samples of ActiveX and Java components. Check out the great new whitepapers on java applets, ActiveX control creation with MFC, and COM and ActiveX.

Until next time …

Since taking early retirement as commander of the Starship Enterprise and joining Microsoft, Mary Haggard has worked her way through the ranks to her lifelong goal, being Program Manager for the MSDN Online Web publishing team. Mary once worked in a paper mill, so she knows pulp when she sees it.
For technical how-to questions, check in with the Web Men Talking, MSDN Online's answer pair.