Frequently Asked Questions About the HotJava Browser

# HotJavaTM Browser for Solaris FAQ

This collection of frequently asked questions (FAQ) provides brief answers to common questions about the HotJavaTM Browser.

Please look at this page as well as at the HotJava Browser's Known Bugs page before you submit a bug or request a feature.

The Troubleshooting section is located toward the bottom of this page.

- What is the current version of the HotJava Browser?

  HotJava Browser 1.1.4.

- What is the difference HotJava for Solaris and HotJava Browser?

  HotJava for Solaris 1.1.4 is based on the HotJava Browser 1.1.4 from JavaSoft. It is delivered as a Solaris package, SUNWdthj, for both Solaris sparc and intel platforms. It also includes support for WebNFS and 40-bit SSL.

  Please see the HotJava for Solaris Features page for more details.

- What version of HTML do you support?

  The HotJava Browser 1.1.4 supports HTML 3.2 plus Tables, Frames, and the <OBJECT> tag.

- What platforms does the HotJava Browser run on?

  HotJava for Solaris 1.1.4 is supported on Solaris 2.5.1 for both sparc and intel platforms.

  Other HotJava Browser releases can be downloaded from the JavaSoft web site.

- Is HotJava Browser a competitive product to Netscape Navigator or Microsoft Internet Explorer?

  No. HotJava Browser is a lightweight, modular, and highly-customizable solution for OEMs and developers creating Web-enabled devices and applications. Its small footprint makes it an ideal, scalable solution for a variety of devices, from NCs to desktop PCs. In addition, the HotJava Browser includes the HTML Component, a JavaBeans component for displaying HTML.

- How can I customize HotJava Browser's user interface?

  The HotJava Browser's text-based properties files allow extensive customization to its user interface, including operations such as:

  - removing or adding items on the menu bar
  - changing the contents of the menus
  - modifying window size, icons, background colors, fonts, and graphics
  - changing the look and placement of the menu bar, status, and locator bars

  For more information, see the Customizing section of the HotJava Browser User's Guide (available from the Help menu).

- Can the HotJava Browser run any Java application?

  Strictly speaking, the HotJava Browser is an application that runs applets by downloading them and displaying them within the browser.

  As far as programming conventions are concerned, both applets and applications are programs written in the Java programming language. Applications are complete programs that can run independently, whereas applets are programs that require another application (such as a browser) to run.

- What is the difference between the HotJava Browser and HotJava Views?

  HotJava is a software base that can be used to build Internet- and intranet-aware applications. The HotJava Browser is such an application--a scalable, customizable, extensible, standards-based, Web browser for enterprise users. HotJava Views is an integrated collection of intranet-aware applications that serves as a user environment for network computers. HotJava Views provides email, calendar, employee directory, and the HotJava Browser applications.

- What is the difference between an applet written in the Java programming language and a JavaScript script?

  The Java programming language is an object-oriented language with classes and inheritance. To create an applet, you write a program and compile it into a file of bytecodes, then include a reference to the applet in an HTML file. When a browser compatible with the Java application environment, such as the HotJava Browser, encounters the applet, it downloads and runs the applet.

  JavaScript is an object-based scripting language with built-in extensible objects but no classes or inheritance. JavaScript commands are embedded directly in an HTML file, and you can use JavaScript scripts to connect HTML content to applets written in the Java programming language.

- Can applets communicate with one another in the HotJava Browser?

  In a word, yes. We have a short paper on Inter-Applet Communication that deals with this and other issues, such as:

  - how applets can share static data members
  - when applet classes are reloaded
  - cleaning up applet resources
  - page reloading

- Does the HotJava Browser do caching?

  The HotJava Browser caches memory images, audio clips, applet classes, and documents (HTML pages). The Clear Cached Images item on the View menu clears, or flushes, these caches by reinitializing the tables that represent them, then doing garbage collection until it recovers the maximum amount of memory. (Garbage Collection is a common term for recovering, or deallocating, memory that an application has allocated for itself but no longer needs.)

  The image and document caches use a form of soft-referencing whereby the garbage collector is free to remove any image, for example, that is not being used. The next time that image is needed, the browser reloads it automatically. This enables in-memory caching without consuming all available memory.

  The HotJava Browser remembers recently visited URLs and HTTP cookies associated with particular URLs, and it remembers to highlight recently visited links, even between HotJava Browser sessions.

- Can I use the keyboard (instead of the mouse) to navigate the HotJava Browser menus?

  Yes, certain keyboard accelerators are implemented. Whenever you see a keyboard equivalent in a menu, you can use that sequence as an accelerator. For example, on Solaris, Control+o in the main HotJava Browser window displays the Open dialog box, and Control+l (lower case L) in the Remembered Places window displays the Add New List dialog box.

  You can change a keyboard accelerator by editing your properties file (see Customizing HotJava Browser in the HotJava Browser User's Guide for information on modifying the properties files).

- How can I adjust my fonts so HotJava Browser looks more like other browsers?

  Choose Edit->Preferences->Display and change the typeface to Serif and the typeface size to Small.

- Can I send email using the HotJava Browser?

  Yes. You can send email by setting Mail preferences then choosing Send Mail from the File menu.

- What is the difference between external content viewers and content handlers?

  An external content viewer is an executable (external to the browser) that the browser can launch. Like a plugin, it can be written in the Java programming language or some other language, as long as the platform the browser is executing on supports that executable.

  A content handler is a set of classes for the Java platform that extends, and runs in the same address space as, the browser.

  A content handler displays within the browser; the external viewer displays outside the browser.

- When you debug an applet in the HotJava Browser, where does System.out.println get sent? Is there something like the console that you find in Netscape browsers?

  Yes. HotJava now supports a console as well as sending the output to the process's standard output pipes. If you use the HotJava Console (you start it with View->Console), the output isalso sent to standard output.

  On Solaris systems, applet print output gets sent to /dev/null by default. To see system state messages, including applet diagnostics as they're generated, run the HotJava Browser with the "-log /dev/tty" command line option. Or, if you prefer, you can set the HOTJAVA_LOG environment variable to /dev/tty. If you wish to send HotJava Browser diagnostic output to a file, you can substitute a file name for /dev/tty with either the -log command line option or the HOTJAVA_LOG environment variable.

  If an applet fails to run, the HotJava Browser displays a broken applet icon. Click on the broken applet icon to view a list of the applet exceptions to help you debug your applet.

- Does HotJava Browser use a color cube for reserving colors? Can I get a color map to make sure the colors I use display properly?

  The Java platform uses a sophisticated adaptive algorithm to map images to whatever colors happen to be on the screen. It uses a rather large and dense virtual color cube and, in general, does a very good job of mapping colors to the screen. Use whatever colors you want.

- How can I keep up with news about HotJava?

  You can read the newsgroups:

  - alt.www.hotjava:
    about the HotJava World Wide Web browser
    or
  - comp.lang.java.*: Newsgroups about the Java programming language, 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

  Note that not all news servers carry alt.* newsgroups, so alt.www.hotjava may not be available at your site.

  Or, you can connect to our Web site at http://java.sun.com

- Who are the target customers for HotJava Browser?

  - Thin-client OEMs (creating products like NCs, screen phones, kiosks, etc.) who need a lightweight, customizable browser for their devices
  - ISVs and Webtop application developers who need a modular, customizable browser or component to embed into their Web-aware applications
  - Corporate intranet developers who need a customizable, easily-configurable, house-branded browser

## Troubleshooting

- Is my firewall preventing HotJava Browser from making connections?

  Possibly, especially if you haven't configured your proxy servers. Choose Proxies from the Preferences submenu of the Edit menu. Contact your system administrator for the proxy information specific to your site. For more information, see the HotJava Browser User's Guide (choose User's Guide from the HotJava Browser Help menu).

- When I download a file of a certain type, HotJava Browser displays a page that says "Unable to Launch Viewer", but nothing happens. What do I do?

  A frequent cause of this problem is not setting the `exec.path` property in your properties file. The exec.path property is a vertical-bar-separated list of full directory names on your machine where HotJava Browser should look for executable external content viewer applications. For example, a typical setting of this property for Solaris would be:

      exec.path=/usr/dt/bin|/usr/openwin/bin|/usr/bin

  See the section on setting the exec.path property in the HotJava Browser User's Guide (available from the Help menu) for more information.

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