Try the Java applet version
FREQUENTLY ASKED QUESTIONS ABOUT JAVATM

This collection of frequently asked questions (FAQ) provides brief answers to many common questions about Sun's JavaTM Platform, programming language, and the Java Development Kit (JDK). It also provides links to more detailed information available from this web site. Please check here for answers before posting a question to one of the Java-related newsgroups or before sending email to any of the addresses at JavaSoft E-mail Addresses.

A. Getting started with Java:
availability, latest releases, ports, downloading, installing, Java

B. Getting information and staying in touch:
the Java name, documentation of all sorts, newsgroups, mailing lists, Java courses, bug reports

C. Java-enabled Netscape:
which versions, alpha/beta applets

D. Marketing, licensing, and planning:
licensing, logos, plans

E. Troubleshooting:
error messages

We try to make as much information as possible available through our Web site, http://java.sun.com/. If you have trouble finding the information you need there, please let us know.

## A. Getting started with Java:

A1. What releases of Java are currently available? What do they contain?
A2. What platforms is the 1.0.2 JDK available on?
A3. What about a version for my favorite platform XYZ? When can I get it?
A4. How do I download Java and/or JDK? How do I install it?
A5. How can I get started with programming in Java?
A6. Do I need special server software to use applets?
A7. Who is licensing Java?
A8. Is JavaScript available? How do I find out more about it?
A9. What are the security problems I've heard about JavaScript scripts?
A10. I can't find the API documentation on any classes in the sun.* packages. Where is it?
A11. Where can I get the Java source code?

A1. What releases of Java are currently available? What do they contain?

The Java programming language is currently shipping as a product known as the Java Development Kit. The current final Java release is JDK 1.0.2. A later version is JDK 1.1, which will become final sometime before the end of March 1997.

Each release of the Java Developers Kit (JDK) contains:

- Java Compiler
- Java Interpreter
- Java Class Libraries
- Java Applet Viewer
- Java Debugger and other tools

To run Java 1.0.2 applets, use Netscape Navigator 2.0 or other browsers that support Java applets.

For details, see:

> The JavaTM Development Kit (http://java.sun.com/products/JDK/index.html)

A2. What platforms is the JDK 1.0.2 available on?

The JDK 1.0.2 is available on these platforms:

- SPARC Solaris (2.3 or later)
- Intel x86 Solaris
- Windows NT/95 (Intel x86)
- Macintosh 7.5

A3. What about a version for my favorite platform XYZ? When can I get it?

These are extremely popular questions, and important ones. What we can currently say is:

        Amiga, Linux, NeXT, OS/2, Windows 3.1, Windows 32s, ...

We've provided our source code to make third-party ports like these possible, but we are not officially overseeing or tracking them. For more information, please check out:

> Platforms Supporting Java (http://java.sun.com/mail/external_lists.html)

A4. How do I download Java and/or JDK? How do I install it?

You can get our releases either with a World Wide Web (WWW) browser or by anonymous ftp. For details, including installation instructions, visit:

> The JavaTM Development Kit (http://java.sun.com/products/JDK/)

Choose the version of the JDK you want, and go from there.

A5. How can I get started programming in Java?

See, Getting Started with Java.

A6. Do I need special server software to use applets?

No. Java applets may be served by any HTTP server. On the server side they are handled the same as any other file, such as a text, image, or sound file. All the special action happens when the applet class files are interpreted on the client side by a Java-enabled browser, such as HotJava or Netscape 2.0.

A7. Who is licensing Java?

See our "Who's Licensing Java?" page:

> Who's Licensing Java? (http://java.sun.com/licensees.html)

A8. Is JavaScript available? How do I find out more about it?

The initial version of JavaScript is available in current releases of Netscape Navigator 2.0. For more information, including a pointer to the full press release, see the Netscape JavaScript page:

> Netscape JavaScript

A9. What are the security problems I've heard about JavaScript scripts?

JavaScript is a scripting language used with Netscape Navigator 2.0. There have been reports of privacy problems with JavaScript, and Netscape is committed to addressing those concerns. JavaScript cannot be used to invoke Java applets. The privacy problems reported with JavaScript are not present in Java applets.

A10. I can't find the API documentation on any classes in the sun.* packages. Where is it?

The short answer is that we provide documentation only for the public classes in java.* (except sun.tools). We do not provide documentation for sun.* because those are the Sun-specific implementation, and specifically not part of the Java API standard, and are therefore subject to change.

In general, we don't provide javadoc documents for sun.* classes in order to discourage developers from writing programs that use them. For further explanation, see:

> Why Developers Should Not Write Programs Using 'sun' Packages

The documentation for sun.* is in the doc comments in the source code release available separately from the JDK, mentioned in the next question A11. For example, the doc comments for sun.net are in the source files located at:

       /src/share/sun/sun/net/*.java

This source code release does not include javadoc documentation. You would have to generate the docs yourself using javadoc.

A11. Where can I get the Java source code?

JavaSoft has two separate bundles of source code that you can obtain at no charge:

- The JDK itself contains a file called `src.zip` that contains the source code for the public classes in the `java` package. Because this does not contain sun.* classes, you cannot do a complete build of Java from these source files. These source files are for your information, to supplement the documentation, so you can see how Java works.
- The full source code release is available from us by going to the Non-commercial Licensing Guidelines. From there, click on "Java Internal Noncommercial Use Source License", and follow the instructions. This includes sun.* and all of the files necessary to do a build of Java, for both Solaris and Windows 95/NT.

## B. Getting information and staying in touch:

B1. Where did the Java name come from? What does it stand for?
B2. Can the Java team keep me informed of latest developments?
B3. What newsgroups carry information about Java?
B4. What email addresses are available? w
B5. What documentation is available? In what formats? How can I get it?
B6. Can you send me information by regular mail or by email?
B7. Can I be an alpha or beta tester?
B8. Are Java programming courses available? Where? At what price?
B9. How do I file bug reports or feature suggestions?

B1. Where did the Java name come from? What does it stand for?

The name was chosen during one of several brainstorming sessions held by the Java team. We were aiming to come up with a name that evoked the essence of the technology -- liveliness, animation, speed, interactivity, and more. "Java" was chosen from among many, many suggestions. The name is not an acronym, but rather a reminder of that hot, aromatic stuff that many programmers like to drink lots of.

B2. Can the Java team keep me informed of latest developments?

We no longer keep a list of people to inform; when we started that, we never expected that so many people would be writing to us every day! If you'd like to keep informed, the best way is to visit our Web site

> JavaSoft Home Page (http://java.sun.com/)

periodically and participate in the Java-related newsgroups. Note in particular that our "What's New" page:

> What's New at JavaSoft (http://java.sun.com/nav/new/)

provides an overview of the most recent developments, press releases, and so on concerning Java.

B3. What newsgroups carry information about Java?

Several newsgroups are currently available, including:

> comp.lang.java.advocacy comp.lang.java.announce comp.lang.java.api comp.lang.java.misc comp.lang.java.programmer comp.lang.java.security comp.lang.java.setup comp.lang.java.tech

B4. What email addresses are available?

Information about our internal e-mail addresses is available at

> JavaSoft E-Mail Addresses (http://java.sun.com/mail.html)

B5. What documentation is available? In what formats? How can I get it?

We provide a wide range of documentation (white papers, API specifications, programmer's guide, and more), reachable from our documentation page:

> Documentation Index (http://java.sun.comnav/read/docindex.html)

Most of our documents are available in HTML, PostScript and PDF formats.

B6. Can you send me information by regular mail or by email?

Sorry, but we're mainly set up to distribute information through our Web site (http://java.sun.com/) and ftp site (java.sun.com). We want to get as much information out and available as possible, but we can only handle the volume via these customer-initiated mechanisms.

B7. Can I be an alpha or beta tester?

Yes, that's essentially what you're doing when you use our beta release software and send in bug reports. We generally don't have separate formal programs for early-release testing.

B8. Are Java programming courses available? Where? At what price?

SunService will be providing Java programming courses at sites around the world; see

> Sun Educational Services (http://www.sun.com/sunservice/suned/)

B9. How do I file bug reports or feature suggestions?

See instructions on our bug report page:

> Submitting a Bug or Feature Request

We will not be able to acknowledge each report individually. Please accept our gratitude in advance -- your feedback is crucial to our work.

## C. Java-enabled Netscape:

C1. Can all Netscape 2.0 versions run Java applets?
C2. Can you help me with using Java in Netscape?

C1. Can all Netscape 2.0 versions run Java applets?

Netscape 2.0 supports Java 1.0 applets on many but not all platforms. See the release notes for your platform at:

> Netscape Navigator Release Notes

Java-enabled versions of Netscape 2.0 will only run beta and 1.0.2 applets, which can be written with the 1.0.2 Java Developers Kit (JDK). Be aware that there are many Web pages with alpha applets, which Netscape 2.0 will not handle. You can distinguish between alpha and beta applets by looking at the html source for a page: alpha applets use the <app> tag, whereas beta applets use the <applet> tag.

C2. Can you help me with using Java in Netscape?

For questions that specifically concern installation, troubleshooting, feature availability, and how to do something specific with applets in the Netscape browser, it's best to ask Netscape directly. For instance, to report Netscape bugs, you can use:

> Netscape Bug Report

## D. Marketing, licensing, and planning:

D1. Is Java free? Where can I get information on licensing?
D2. Can I use the Java logo?
D3. What are your plans for XXX functionality? Why haven't you done YYY?
D4. Can you comment on company ZZZ's plans for licensing and using Java?
D5. How can I invest in Java on the stock market?

D1. Is Java free? Where can I get information on licensing?

We have guidelines on our Web site for using and/or licensing Java technology; see

> Licensing Information (http://java.sun.com/nav/business/)

If you have further commercial or licensing questions, please contact our representatives at 1-800-JAVASOFT, for international callers, please dial +1 512 434-1591.

D2. Can I use the Java logo?

Sun does not authorize the use of the Java logo. For more information about this and other special developer logos, please see:

> Java Trademark Guidelines

D3. What are your plans for XXX functionality? Why haven't you done YYY?

We welcome all input regarding Java -- we will read and consider it. We're keeping many more options in mind than appear in our current releases. However, because we are focusing on moving toward our next release, we have time to answer only a small number of such questions. For APIs in particular, see:

> Java API Overview

D4. Can you comment on company ZZZ's plans for licensing and using Java?

No, we need to let other companies speak for themselves. We can only refer you to official press releases. For pointers to recent press releases, see our "What's New" page:

> What's New at JavaSoft

D5. How can I invest in Java on the stock market?

Java technology is a product of Sun Microsystems, Inc., which is traded on NASDAQ under the symbol SUNW.

## E. Troubleshooting:

E1. Will Java work with DOS file size limitations (8.3)?
E2. javac: Superclass java.applet.Applet of class HelloWorld not found.
E3. How do I stop the copyright notice from appearing every time I start the Windows NT/95 version of appletviewer?

E1. Will Java work with DOS file size limitations (8.3)?

No, they rely on many files with longer names than the old DOS limits. Even if your drive allows long file names, be careful not to unzip your release package with WinZip, since this will truncate the file names to the old 8.3 DOS limits. Instead, extract the files from a DOS window, without WinZip, and make sure that the resulting files have their full (long) names.

E2. javac: Superclass java.applet.Applet of class HelloWorld not found.

The examples in the programmer's guide have been updated to conform to the new applet API in our 1.0.2 Java Developers Kit (JDK). "Superclass not found" error messages are typical if you try to compile Java 1.0 beta code with an alpha version of javac. The recommended fix is to download a copy of the JDK, and do all further development with that.

Another potential source of this error message is incorrect capitalization of either the file name or the class name in in the file. The Java system is case-sensitive, so a HelloWorld class is different from a helloWorld class, and so on.

E3. How do I stop the copyright notice from appearing every time I start the Windows NT/95 version of appletviewer?

The appletviewer looks for a .hotjava directory inside your home directory to determine whether you are starting it for the first time. If the directory is not found, the appletviewer will pop up the copyright notice. The workaround is to manually create the .hotjava directory in your home directory. The following paragraphs explain how to do this.

The appletviewer is written to recognize three MS-DOS environment variables for the location of a user home directory: it uses either HOME or the combination of HOMEDRIVE and HOMEPATH. Under Windows NT3.51, the HOMEDRIVE and HOMEPATH environment variables are set automatically. Under Windows 95, you will need to set the HOME environment variable to point to an existing directory.

Once your home directory is set, all you need to do for Windows NT3.51 is to create the .hotjava directory inside of it:

            mkdir %HOMEDRIVE%%HOMEPATH%\.hotjava

In Windows 95, the easiest method is to edit the AUTOEXEC.BAT file, adding the following line:

            set HOME=C:\

Then save the file and reboot, so that the change to take effect. Once your computer has rebooted, open a DOS window and execute the following command:

            mkdir %HOME%.hotjava

05-May-97 Copyright © 1995-97 Sun Microsystems, Inc. All Rights Reserved.