From neal@bcn.boulder.co.us Fri Oct 27 00:59:06 1995 Received: (from neal@localhost) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) id AAA20298 for neal; Fri, 27 Oct 1995 00:59:06 -0600 Date: Fri, 27 Oct 1995 00:59:06 -0600 From: Neal McBurnett Message-Id: <199510270659.AAA20298@bcn.boulder.co.us> To: neal@bcn.boulder.co.us Subject: POST test test POST option From neal.mcburnett@gw2.att.com Fri Oct 27 01:14:03 1995 Received: from gw2.att.com (gw2.att.com [192.20.239.134]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with SMTP id BAA21019 for ; Fri, 27 Oct 1995 01:14:02 -0600 Received: from drmail.dr.att.com (bighorn.dr.att.com) by ig1.att.att.com id AA03681; Fri, 27 Oct 95 03:00:06 EDT Received: by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA08195 for neal@bcn.boulder.co.us; Fri, 27 Oct 95 01:01:13 MDT Received: from 135.9.214.60 ([135.9.214.60]) by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA08189 for neal@bcn.boulder.co.us; Fri, 27 Oct 95 01:01:04 MDT Message-Id: <9510270701.AA08189@drmail.dr.att.com> Date: Fri, 27 Oct 95 08:01:12 0800 From: Neal McBurnett X-Mailer: Mozilla 1.1N (Macintosh; I; 68K) Mime-Version: 1.0 To: neal@bcn.boulder.co.us Subject: POST - democratic senatorial page X-Url: http://www.dscc.org/d/dscc.html Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii http://www.dscc.org/d/dscc.html From neal.mcburnett@gw2.att.com Fri Oct 27 01:23:59 1995 Received: from gw2.att.com (gw2.att.com [192.20.239.134]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with SMTP id BAA21387 for ; Fri, 27 Oct 1995 01:23:58 -0600 Received: from drmail.dr.att.com (bighorn.dr.att.com) by ig1.att.att.com id AA05858; Fri, 27 Oct 95 03:12:54 EDT Received: by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA08900 for neal@bcn.boulder.co.us; Fri, 27 Oct 95 01:14:00 MDT Received: from 135.9.214.60 ([135.9.214.60]) by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA08898 for neal@bcn.boulder.co.us; Fri, 27 Oct 95 01:13:57 MDT Message-Id: <9510270713.AA08898@drmail.dr.att.com> Date: Fri, 27 Oct 95 08:13:59 0800 From: Neal McBurnett X-Mailer: Mozilla 1.1N (Macintosh; I; 68K) Mime-Version: 1.0 To: neal@bcn.boulder.co.us Subject: POST Ron Wyden's Home Page X-Url: http://www.house.gov/wyden/welcome.html Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii http://www.house.gov/wyden/welcome.html From neal.mcburnett@gw2.att.com Tue Nov 7 22:47:44 1995 Received: from gw2.att.com (gw2.att.com [192.20.239.134]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with SMTP id WAA28910 for ; Tue, 7 Nov 1995 22:47:43 -0700 Received: from drmail.dr.att.com (bighorn.dr.att.com) by ig2.att.att.com id AA00716; Wed, 8 Nov 95 00:48:35 EST Received: by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA09332 for neal@bcn.boulder.co.us; Tue, 7 Nov 95 22:47:30 MST Received: from 135.64.16.59 ([135.64.16.59]) by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA09330 for neal@bcn.boulder.co.us; Tue, 7 Nov 95 22:47:25 MST Message-Id: <9511080547.AA09330@drmail.dr.att.com> Date: Wed, 08 Nov 95 04:47:38 0700 From: Neal McBurnett X-Mailer: Mozilla 1.1N (Macintosh; I; 68K) Mime-Version: 1.0 To: neal@bcn.boulder.co.us Subject: POST Lamar Alexander's page X-Url: http://www.Nashville.net/~lamar/info/contributions.html Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii http://www.Nashville.net/~lamar/ From neal.mcburnett@gw2.att.com Tue Nov 7 22:54:53 1995 Received: from gw2.att.com (gw2.att.com [192.20.239.134]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with SMTP id WAA29253 for ; Tue, 7 Nov 1995 22:54:52 -0700 Received: from drmail.dr.att.com (bighorn.dr.att.com) by ig2.att.att.com id AA04166; Wed, 8 Nov 95 00:55:46 EST Received: by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA09575 for neal@bcn.boulder.co.us; Tue, 7 Nov 95 22:54:42 MST Received: from 135.64.16.59 ([135.64.16.59]) by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA09573 for neal@bcn.boulder.co.us; Tue, 7 Nov 95 22:54:39 MST Message-Id: <9511080554.AA09573@drmail.dr.att.com> Date: Wed, 08 Nov 95 04:54:52 0700 From: Neal McBurnett X-Mailer: Mozilla 1.1N (Macintosh; I; 68K) Mime-Version: 1.0 To: neal@bcn.boulder.co.us Subject: POST candidate links from cityvote X-Url: http://www.cityvote.org/cityvote/links/candlink.htm Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii http://www.cityvote.org/cityvote/links/candlink.htm From neal.mcburnett@gw2.att.com Fri Dec 1 19:01:49 1995 Received: from gw2.att.com (gw2.att.com [192.20.239.134]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with SMTP id TAA19852 for ; Fri, 1 Dec 1995 19:01:34 -0700 Received: from drmail.dr.att.com (bighorn.dr.att.com) by ig1.att.att.com id AA10158; Fri, 1 Dec 95 20:59:48 EST Received: by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA17699 for neal@bcn.boulder.co.us; Fri, 1 Dec 95 19:01:14 MST Received: from 135.64.16.59 ([135.64.16.59]) by drmail.dr.att.com (4.1/EMS-1.1 SunOS) id AA17697 for neal@bcn.boulder.co.us; Fri, 1 Dec 95 19:01:11 MST Message-Id: <9512020201.AA17697@drmail.dr.att.com> Date: Sat, 02 Dec 95 01:01:52 0700 From: Neal McBurnett X-Mailer: Mozilla 1.1N (Macintosh; I; 68K) Mime-Version: 1.0 To: neal@bcn.boulder.co.us Subject: POST oregon election urls X-Url: http://www.vote-smart.org/campaign_95/Oregon/ Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii http://www.vote-smart.org/campaign_95/Oregon/ http://www.sos.state.or.us/ http://www.teleport.com/~wyden/ http://www.wwwmedia.com/JackRoberts/ http://www.europa.com/paulus/ http://www.erehwon.com/defazio/ From ietfol@mci.ietf.org Sun Dec 3 11:47:27 1995 Received: from ws011. (ws011.internetMCI.ietf.org [206.103.68.11]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with SMTP id LAA06022 for ; Sun, 3 Dec 1995 11:47:26 -0700 Received: from ws011 (localhost) by ws011. (5.x/SMI-SVR4) id AA00717; Sun, 3 Dec 1995 12:44:52 -0600 Sender: ietfol@mci.ietf.org Message-Id: <30C1F024.4D49@mci.ietf.org> Date: Sun, 03 Dec 1995 12:44:52 -0600 From: OpenLook User at 34th IETF X-Mailer: Mozilla 2.0b3 (X11; I; SunOS 5.4 sun4m) Mime-Version: 1.0 To: neal@bcn.boulder.co.us Subject: POST TREX - java-based market simulation X-Url: http://www.ctr.columbia.edu/~nemo/java/trex.html Content-Type: multipart/mixed; boundary="---------------------------147421552519985" This is a multi-part message in MIME format. -----------------------------147421552519985 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit http://www.ctr.columbia.edu/~nemo/java/trex.html -----------------------------147421552519985 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="trex.html" TREX TREX: The Resource EXchange (by nemo)

Get a Java (version 1.0 Beta) enabled browser (e.g. Netscape 2.0 and higher) to view these applets.

The two bars in the middle represent the amount of stuff available on the market (yellow bar), and it's current price (blue). In white is the price as a function of time, and the text at the top gives you the price changes. Click anywhere except on a button to get instantaneous price and stuff levels in the scrolling text. There are four players, each with a certain amount of money (green), and amount of stuff (yellow). The number in red is the player's net worth, i.e. capital + current value of stuff. You are player 0 on the left, and you can buy or sell one unit of stuff at a time. Players 1,2 and 3 act by themselves, but you may also force player 1 to buy or sell one unit whenever you want. Are you smart enough to beat players 2 and 3? It shouldn't be too hard now, but they're gonna get better.

Future versions will support multiple human players, each accessing TREX from anywhere on the net and playing each other as well as programmed players like 1,2, and 3 above.

Here's the source. -----------------------------147421552519985-- From ietfol@mci.ietf.org Sun Dec 3 12:15:51 1995 Received: from ws011. (ws011.internetMCI.ietf.org [206.103.68.11]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with SMTP id MAA06229 for ; Sun, 3 Dec 1995 12:15:50 -0700 Received: from ws011 (localhost) by ws011. (5.x/SMI-SVR4) id AA00744; Sun, 3 Dec 1995 13:13:16 -0600 Sender: ietfol@mci.ietf.org Message-Id: <30C1F6CC.623F@mci.ietf.org> Date: Sun, 03 Dec 1995 13:13:16 -0600 From: OpenLook User at 34th IETF X-Mailer: Mozilla 2.0b3 (X11; I; SunOS 5.4 sun4m) Mime-Version: 1.0 To: neal@bcn.boulder.co.us Subject: POST J*** Notes X-Url: http://www.io.org/~mentor1/phpl.cgi?jn951124.html Content-Type: multipart/mixed; boundary="---------------------------2448181694865" This is a multi-part message in MIME format. -----------------------------2448181694865 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit http://www.io.org/~mentor1/phpl.cgi?jn951124.html -----------------------------2448181694865 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="phpl.cgi" J*** Notes Mentor Software Solutions presents:

J*** Notes
for November 24, 1995

J*** Notes is a weekly summary of information about the Java language and the HotJava(tm) browser, culled from the mailing lists and news groups. J*** Notes is in no way connected to Sun Microsystems, originators of Java and HotJava.
Due to time constraints, not all that transpires in the mailing lists and news groups is reported. What you see here reflects my own eclectic interests. While we attempt to give a fair and unbiased portrayal of the exchanges, we offer no guarantees that the information contained here is accurate, useful for anything other than your entertainment, or that it won't cause your hair to fall out. We invite helpful comments.
Java, HotJava, and Sun are trademarks of Sun Microsystems.
All other product names mentioned herein are the trademarks of their respective owners.


J*** Notes is copyright © 1995, David Forster.
Individual items are copyright © 1995, David Forster, Wm D. Clendening, Mike Shaver, Rehan Zaidi, and R.E. Fikki.
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Sections are separated by "coffee bean bars." To return to the table of contents, click on any coffee bean bar (except this one).

The Contributors

J*** Notes is produced by David Forster (de facto editor), William D. Clendening, Mike Shaver, Rehan Zaidi, and Rocky Fikki. We're still trying to get the kinks out of what we're doing, so please bear with us for the next few weeks. (It ain't easy slogging through about 800 messages weekly, and then organising what's summarised later.)

Wm D. Clendening (wdclen@pobox.com) is finishing his PhD in chemical physics. He became interested in Java because of a long standing interest in personal agents. Initially, he was bewitched by the hype of Telescript; but has recently seen the one true light - Java. He hopes to make Java an integral part of how he earns his bread.

Mike Shaver (shaver@neon.ingenia.com) is a network applications and security specialist for Ingenia Communications Corporation in Ottawa, Ontario, Canada. He's had a soft spot for Java ever since he first encountered it in April of 1995, and has been trying to work it into every nook and cranny of his life since. A recent high-school graduate, he's going to be attending Carleton University in January, in a Program To Be Named Later. His other projects including Linux kernel hacking (especially the networking), Ultimate and theatre.

Rehan Zaidi (arzaidi@novice.uwaterloo.ca) is an Electrical Engineering student at the University of Waterloo in Waterloo, Ontario, Canada. He is presently employed as a co-op student by Bell-Northern Research in Ottawa. Aside from his academic interests in telecommunications and semiconductor devices, Rehan spends too much time trying to keep up-to-date with Internet applications like Java.

R.E. Fikki (rfikki@paradise.littleblue.com) recently started his own (Web Presence/Design Firm: WEB CREATIONS) over the past few years he has spent much of his time dealing with internet related applications. Having focussed his attention on Java, he is now looking forward to the future capabilities that it will bring to the WWW. He has a Bachelors Degree in Chemistry, and worked as an environmental consultant before fine-tuning his internet related skills.

And of course, I am David Forster, the bloke what started this thing. I've been studying and working as a computer professional for almost 20 years. The last five years I taught at the Department of Computer Science at York University, but now I consult for a living as the proprietor of Mentor Software Solutions, and Java is fast becoming my raison d'etre in that regard. So, if anyone needs any work done, or has some good leads... let me know! (phone: +1-905-832-4837).

... and a Different Request

Many people have volunteered to help with the Notes, and we're currently going through the list of people who have offered. We will probably eventually need more help still. We'll put out another request when that time comes. We have another need right now, and that is to find out how we can serve you better. Our survey has been delayed one week, pending our making up our minds what to ask you... Please tune in again next week when we'll have a reader survey prepared for you all, which we'd very much like you to fill out then. And as usual, please let us know what you think about it.
_________________________________________

Table of Contents

  1. Announcements
  2. Features
  3. Discussions
  4. Bugs and Warnings
  5. Comments
  6. Queries
  7. Class Exchange
  8. FAQ candidates
  9. Help wanted
  10. Errata
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Announcements

  • vanzyl@silas.cc.monash.edu.au announced an Australian JUG, and a Java Programming Contest ("Win a Sparc 5!"). Details at http://sunsite.anu.edu.au/ajug (for best results, use a Java-aware browser, especially if you want details on the programming contest!).
  • elharo@sunsite.unc.edu is looking to add a list of JUGs to his FAQ, and asks people to let him know of any groups he hasn't got listed (or if you want to be the contact person for a new group in your area). Please give him the location and contact information, at a minimum.
  • A JAVA-MAC mailing list has been formed in order to discuss software development using Sun Microsystem's Java language on the Apple Macintosh computer (topics: tools, techniques, solutions, tech notes, etc.). Send "SUBSCRIBE JAVA-MAC your@e-mail.address" in the body of a mail message to majordomo@natural.com to subscribe.
  • 8patches@cftnet.com (Matt Perez) is looking for someone who can comment in Java and the changes it will spur in layman's terms. "Your comments would likely show up in national print media." says he.
  • john.zukowski@rssi.com announced the first meeting of the Mid-Atlantic JUG in Vienna, VA, USA, with future meetings to rotate around the area. See http://www.rssi.com/info/majug.html for more information.
  • mangalam@uci.edu has a WAIS archive of various newsgroups, including comp.lang.[perl, java, tcl], that can be accessed without the need of a WAIS proxy (thanks to Johnny Goldman's nifty fwais perl script).
  • The Research Triangle Park, NC Java Users Group has formed. For more information contact Rayme Jernigan
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Real-Time Java (II)

The real-time discussion continued, with lots of Ada-related mud-slinging. The major point should not be whether or not Ada-XX is good/great/whatever, but whether Java is suited to real-time work, how it can be improved, and what you'd want RT Java for. kelvin@iastate.edu provided some light on this: He doesn't think that Java currently provides the necessary support and has proposed some RT Java facilities which he summarises as:
  1. Support for scheduling of periodic, sporadic, dynamic, and ongoing real-time tasks....
  2. Support for static analysis of worst-case execution time ....
  3. Support for measurement of average-case execution times....
  4. Support for real-time garbage collection.
  5. An integrated real-time executive....
RT applets would be able to negotiate with the real-time executive for enough resources, and developers could write them to support variable service quality according to the result of the negotiations.

As for what RT Java would be useful for, he suggests

pen computers, automotive diagnostic computers, video games, telephone switches, personal digital assistants, air traffic control, in-vehicle navigation systems, interactive tv, voice I/O subsystems, tv-top multimedia controllers, digital teleconferencing software, military defense surveillance, robotics, and many more applications. The sophistication and market penetration of embedded computing are rapidly expanding. And there are already many more embedded computers in the world than there are "personal computers."
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Discussions

Encryption and Authentication

There was a lengthy exchange on encryption and authentication. greg@qualcomm.com has implemented a few of the RSAREF functions, although the lack of unsigned arithmetic was proving a hindrance. He has put the code online. Some of the discussion concerned the design of the classes, but it was rather cryptic :-).
david.hopwood@lmh.ox.ac.uk mentioned Eric Young's SSLeay libraries (http://www.psy.uq.oz.au/~ftp/Crypto/) which are free of export/key length problems (they were written in Australia), and are free for commercial and non-commercial use. (This, apparently does not alleviate the anguish induced by the US government upon its citizens because of hassles with patent licenses and the categorisation of encryption software as "munition"! Mik Clarke (an Aussie by his address) claimed that the Australian government also has export restrictions.)

The cost of training

There was a heated debate regarding the fees sun is charging for its training courses. The debate was centered primarily around the fact that it may or may not have been appropriate for them to charge such high fees, if any at all while the language was not completely formulated yet (beta). Comparisons between Microsoft and Sun showed a similar approach to such issues (no charge for promotional sessions, charges for courses).
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Bugs and Warnings

  • capo@ipvvis.unipv.it wonders if the "strange behavior" he sees when clicking on a one element Choice list is a bug.

  • kaj@medialab.ericsson.se says there's a bug in GridLayout that causes a divide by zero for the case of a panel with no elements.

  • mlt.software@ortel.org found that both the appletviewer and jdb seem to want to connect to the net before continuing. One person speculated that it was trying to get the name of the host from the DNS; another thought it was trying to find out if the source to be accessed had been modified since the local copy had been brought in last.

  • Java-based JPEG support in Netscape may not work properly. dwight_aspinwall@theriver.com reports problems with N2B2, but not with the appletviewer.

  • ser@jersey.uoregon.edu reports a documentation bug: The latest Java spec. (p. 21) gives the range of a byte as -256 to 255; should be -128 to 127, inclusive.

  • kenno@servtech.com finds that the colours on a Netscape page with three Netscape frames on it (each with a different colour) change when an Applet is displayed in one of them.

  • steve_lewallen@taligent.com found a few bugs/misfeatures in WinNT 3.5/beta: no transparent components (alpha had 'em), mouse_enter/exit problems: no mouse_enter is generated when leaving a child component encircled by its parent and other weirdness, null pointer exceptions with lots of components in a GUI applet, and Javadoc does not create package documentation.

  • pat@icon-stl.net notes that the beta docs say the ALIGN attribute of an applet is required and wonders if this might be a mistake.
  • AvH replied that this is a mistake and he'll make sure that it is corrected.
  • mattias@cdt.luth.se reports that the method isAbsolute() thinks a (UNIX) link is an ordinary file, so getAbsolutePath() doesn't resolve links. To avoid a security nightmare, he wants to know how to detect/resolve links in the beta release.
    david.hopwood@lmh.ox.ac.uk suggests an untried kludge: read the file's permissions, and then dereference it yourself.

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Comments

  • There's a rumour that the Java "jit" compiler will be available in the first quarter of '96.

  • The GridBagConstraints and GridBagLayout classes are not missing from the JDK beta distribution. They are in java/src/java/awt and just need to be compiled.

  • parrt@lonewolf.parr-research.com is designing a Java code generator for PCCTS.

  • A query from last week asked how to rig compiled classes to be executed as commands without using "java" as part of the command. mellis@tiac.net found that a Win95 solution of associating the .class filename extension falls prey to some mindlessness on the part of Windows, and worked out this incredible hack, um, er, workaround. David Hopwood pitched in with a suggestion to just write a shell file for UNIX.

  • jdart@netcom.com wanted to clarify that it is indeed possible to use native code from within an Applet *as long as the class referring to the native code and the native code itself are located on the client's machine already*. He was concerned that recent messages may have led people to believe this was only possible in an application. Your CLASSPATH and PATH and/or LD_LIBRARY_PATH do need to be set to point to this code, of course. He warns of an apparent bug in Windows Netscape (maybe others?) which causes "an unnamed exception at the point where System.loadLibrary is called" if you create threads in your applet. mrm@puffin.Eng.Sun.COM follows this up, noting that Sun considers this an okay way to load third party DLL's. She does urge us to put only trusted .class files in these directories, and to keep the paths used as simple as possible. Her note nicely sums up some of this.

  • simon@lia.di.epfl.ch has the javac compiler (but not the appletviewer or jdb) for SGI IRIX 5 working, see http://liawww.epfl.ch/~simon/java/irix-jdk.html.

  • gary@kampai.euronet.nl wanted to see an extension to the language to include some low-level bit-twiddling functions like "rotate", which he claims would be useful in encryption, graphics, etc.

  • And on the lighter side, david.hopwood@lmh.ox.ac.uk recommends http://www.digicrime.com/ for the security-impaired. Good substitute for a late-night read when you've run out of horror stories.

  • It seems more people are now interfacing with Oracle, or planning to. References include http://weblogic.com/, http://www.algonet.se/~etoile/p1/index.html (a company called Vincent Engineering), to say nothing of three products just released by Oracle, including a Web Server, Listener, and Agent.

  • carrato@servtech.com comments that running Java animations on a 486SX/33 with 20 megs of memory and Windows NT 3.51 is slow -- animations flicker severely. It's better but still jumpy on a Pentium 60. [Second data point: animations are fairly smooth on my 486 DX4/100 with 16 meg, but what is "smooth?" what "jumpy?"] (He goes on to ask about performance issues, but that horse is dead.)

  • Axel Boldt called for people to drop Java and move to Gnu's GROW project; most of this thread was irrelevant to us (dealing with suggestions sometimes verging on the paranoid that we were Sun's dupes, etc.), but one comment from bhogan@rahul.net was relevant, urging the Gnu people to start developing a "gava" from scratch, to avoid possible future legal hassles.

  • robert_dant@msn.com reports that Borland is just getting started on their Java development tools and a beta will not be available for awhile.

  • daniel@elseware.com says that the Container class needs to have additional methods which can be used to replace specified components with other components
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Queries

  • reid@cps.msu.edu wants to know from folk at other universities if they are using or plan to use Java.

  • Various queries related to layout managers appeared: do they work as documented? Symptoms included components not appearing in their proper places or not appearing at all. [See last week's issue about a question on items dynamically added or removed from a layout.]
    Another question was: do you need a layout manager in place for text positioning on labels to work?

  • bhickman@pierian.com wants to load a gif file in an application (*not* an applet, so the stub stuff is missing).
    flar says it was an unfortunate oversight which may not be fixed for a while. A workaround is to use "one of the undocumented and Sun-specific classes sun.awt.image.FileImageSource which takes a String filename in its constructor, or the sun.awt.image.URLImageSource which takes either a String href or a URL object in its constructors. You would need to do one of:
     Component.createImage(new FileImageSource("/tmp/myimage.gif"));
 Component.createImage(new URLImageSource("http://myhost/a.gif"));
 Component.createImage(new URLImageSource(url));
    "
  • bcr1@inel.gov needs help getting a UDP Socket going. Can the sun.net.DatagramSocket be used? If so, where is the documentation?
    michael@earthlight.com suggests that classes in sun.net.* (like that mentioned) will do UDP sockets, but would also like to have some documentation.

  • bharat@Corp.Sun.COM needs to know how to trap events BEFORE they get to a TextArea object?
    dufourd@elec.enst.fr replies with 
    public void postEvent(Event e) {
  super.postEvent(e);
  if (e.id == Event.MOUSE_ENTER) requestFocus();
}
    If your component does this, it gets the focus when the mouse is on it.

  • rbk@ibeam.jf.intel.com wants more flexibility in dealing with components, noting that java.awt.Button only provides an "action" hook (and no mouse down/up events), and java.awt.TextField and java.awt.TextArea don't provide access to keystrokes. Are there plans to open this up more in a later release?

  • daniel@elseware.com wants the contents of one choice list (not the selected item) to depend on a selection in another choice, and asks if there's a neater way than removing the old choice component and replacing it with a new one.

  • michel@mmania.com was surprised when the code b = new ( "Class"+"A" ); produced the error message: test.java:7: 'new(...)' not supported.
    This is obsolete (he was working from the Alpha spec.). Something like: b = Class.forName("Class"+"A").newInstance(); will work.

  • kristin@kristin.com asked last week if different parts of applets can be loaded from different URLs
    This week simonr@neepneep.uk.su>

    Transfer interrupted!

    -----------------------------2448181694865-- From ietfol@mci.ietf.org Sun Dec 3 12:30:54 1995 Received: from ws011. (ws011.internetMCI.ietf.org [206.103.68.11]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with SMTP id MAA06338 for ; Sun, 3 Dec 1995 12:30:53 -0700 Received: from ws011 (localhost) by ws011. (5.x/SMI-SVR4) id AA00747; Sun, 3 Dec 1995 13:28:20 -0600 Sender: ietfol@mci.ietf.org Message-Id: <30C1FA54.3D7D@mci.ietf.org> Date: Sun, 03 Dec 1995 13:28:20 -0600 From: OpenLook User at 34th IETF X-Mailer: Mozilla 2.0b3 (X11; I; SunOS 5.4 sun4m) Mime-Version: 1.0 To: neal@bcn.boulder.co.us Subject: POST brown: Interactive Illustrations of Color Perception X-Url: http://www.cs.brown.edu/research/graphics/projects/igi/spectrum/beta/ Content-Type: multipart/mixed; boundary="---------------------------19925541820227" This is a multi-part message in MIME format. -----------------------------19925541820227 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit http://www.cs.brown.edu/research/graphics/projects/igi/spectrum/beta/ -----------------------------19925541820227 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Interactive Illustrations of Color Perception

    Interactive Illustrations of Color Perception

    For the color theory portion of the introductory computer graphics course at Brown University (CS123), Professor John Hughes sketched out some ideas for interactive illustrations. These were programmed in Flesh by Jeff Beall, and later ported to C++ and GP (also by Jeff). They have recently been ported to Java by Adam Doppelt. The illustrations will be used during the lectures in the course, and they will also be available to students outside class; the following informal text by Professor Hughes is meant to help guide the viewer in understanding the illustrations. To view the interactive illustrations themselves, you must be running a HotJava compatible browser.

    Colored light arrives at the eye, and somehow gets to the brain, and extensive research shows that the brain perceives the color of the light in a 3-dimensional way -- that is to say, there are three independent components to the brain's perception of color. This matches physiological evidence that there are three types of color-receptor cells in the eye.

    The light that arrives at the eye, however, is a much more complex phenomenon: it consists of photons with varying amounts of energy, which correspond to varying wavelengths (or frequencies) of light. In most ordinary light, there is a mix of various frequencies, and at a macroscopic scale, one can indicate this mix of photons by drawing a graph of intensity versus frequency. If light is generated very carefully, it sometimes consists of photons that all have the same energy, so that the light is of a single frequency. We'll refer to such light as "monospectral." Laser light is the standard example of a monospectral light.

    How does incoming light affect the three types of cells? Let's look at one cell-type at a time, such as the "green" cells (ones that are sensitive to light primarily in the 520 nm wavelength). First of all, at a very coarse level, the response is linear: if the green cells are stimulated by one light and produce one response -- some amount of signal to the brain -- and if in response to a second light and produce another, then when they are stimulated by both lights at once, they produce the sum of the two responses.

    Second, the green cells will respond to monospectral light of many different wavelengths. If we take a variable-frequency light of constant intensity, and measure how much "response" we get from a typical "green cell" in response to this light, we can plot this response against frequency, and call it "the frequency response" of the green cells.

    If we've done this, and we then send the eye a mix of light rather than a pure monospectral light, we can compute the total response by summing up the product of the "incoming light intensity" and the "frequency response" at each frequency. In equations, this is

    or, assuming that we've actually determined the frequency response at every single frequency, we can write this as an integral:

    To compute this integral, we can first compute the product of the two functions, and then compute the area under this product function. Illustration 1 shows this: the user can draw a distribution of input intensity as a function of wavelength; the frequency response of the "green cells" is indicated in the middle, and the product of the two is shown at the bottom. The user draws in this illustration, and all the others, by holding down the left mouse button within one of the red boxes and moving the mouse -- try it and the interaction should rapidly become obvious. The mouse may go outside the box during a single click-and-drag sequence, but it must start inside or nothing will happen. The area under this product curve is shown on the bar indicator at the right. In this illustration, the "frequency response" is not the real frequency response of the green cells, but rather a graph whose shape is somewhat similar, but the method of computing the total response does not depend on the particular shape of the response curve.

    One thing to try here is drawing "input" that's more or less monospectral -- draw a "bar" of light all near one frequency, and note how the total response depends on where you draw the bar -- the total response is largest when the bar is near the "hump" of the response curve.

    Multiple types of color cells

    There are cells other than the green cells in the eye -- there are two other kinds, one more responsive to lower frequencies, and one more responsive to higher frequencies. Naturally, this leads to three different "total responses" to any given input frequency distribution. The second illustration shows this: the reader can draw any input distribution, the three response curves for the three cell types are shown in the middle, the products of these with the input are shown at the bottom, and the upper right shows the three "total responses." Once again, try to see what the total response to "nearly monospectral" lumps of light looks like as you vary the central frequency of the nearly monospectral light.

    Different lights that look the same

    The way we perceive light depends on the three "total responses" produced by the light that enters the eye. It's a surprising fact that different incoming light distributions can generate the same three total responses. The third illustration lets you examine this. In particular, you can draw a nearly uniform frequency distribution on the left side, generating a mix of equal parts of red, green, and blue "total responses." But you can also draw, on the right, a more sawtooth pattern which produces the same total responses. Such pairs of light distributions are called "metamers," or "metameric lights." Try to play with the illustration to see how different two incoming lights can be and still produce the same response in the eye.

    What about reflection?

    Suppose that we shine a light onto a surface. The surface may well be good at reflecting certain frequencies and good at absorbing others. (Indeed, this reflectivity may vary with the angle at which light arrives and departs from the surface, but for a first approximation we'll assume that a single "reflectivity number" at each frequency suffices to characterize the surface). We'll plot this reflectance against frequency, and we can then say when a given distribution of light is shined on the surface that the light that comes off the surface will be the product of the reflectance function and the incoming light distribution. The fourth illustration shows this, and allows the reader to play with examples that are hard to get ahold of in the real world -- materials that reflect more or less a single frequency of light, illuminated by various sorts of light. Try seeing what happens when high-frequency light arrives at a surface that reflects only low-frequency light -- a "very blue light" shining on a "very pure red" surface.

    Next Page

    Questions or feedback on these illustrations should be sent to John F. Hughes.
    Questions on the Java source should be sent to Adam Doppelt. -----------------------------19925541820227-- From Neal.McBurnett@att.com Mon Dec 4 17:17:16 1995 Received: from nic.cerf.net (nic.cerf.net [192.102.249.3]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with ESMTP id RAA21396 for ; Mon, 4 Dec 1995 17:17:15 -0700 Received: from [206.103.69.77] (drop077.internetMCI.ietf.org [206.103.69.77]) by nic.cerf.net (8.6.10/8.6.9) with SMTP id QAA06136; Mon, 4 Dec 1995 16:16:48 -0800 X-Sender: apex@trouble.dr.att.com (Unverified) Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Mon, 4 Dec 1995 18:17:39 -0500 To: jis@mit.edu From: Neal.McBurnett@att.com (Neal McBurnett) Subject: please forward info on IETF PGP key signing (reply-all, POST) Cc: neal@bcn.boulder.co.us (So I can read the response at the conference, please RESPOND TO ALL and keep "POST" in the subject line) I'm the guy that asked you about the PGP signing meeting at the IETF meeting. I looked for the notice starting in the Dec 1 ietf archive (I thought the organizer said he sent it Fri) with no luck. Sorry for the bother, and thanks for your help! Neal.McBurnett@att.com http://bcn.boulder.co.us/~neal/Home.html From ietfol@mci.ietf.org Tue Dec 5 20:48:44 1995 Received: from ws011. (ws011.internetMCI.ietf.org [206.103.68.11]) by bcn.boulder.co.us (8.6.11/8.6.9/CNS-3.5) with SMTP id UAA06606 for ; Tue, 5 Dec 1995 20:48:39 -0700 Received: from ws011 (localhost) by ws011. (5.x/SMI-SVR4) id AA04876; Tue, 5 Dec 1995 21:46:05 -0600 Sender: ietfol@mci.ietf.org Message-Id: <30C511FD.2C23@mci.ietf.org> Date: Tue, 05 Dec 1995 21:46:05 -0600 From: OpenLook User at 34th IETF X-Mailer: Mozilla 2.0b3 (X11; I; SunOS 5.4 sun4m) Mime-Version: 1.0 To: neal@bcn.boulder.co.us Subject: POST mirror site for Project Galileo (JPL) X-Url: http://newproducts.jpl.nasa.gov/galileo/ Content-Type: multipart/mixed; boundary="---------------------------30225321569240" This is a multi-part message in MIME format. -----------------------------30225321569240 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit http://www.jpl.nasa.gov/galileo/ mirror site http://newproducts.jpl.nasa.gov/galileo/ -----------------------------30225321569240 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Project Galileo (JPL)

    Project Galileo: Bringing Jupiter to Earth

    Welcome to the Project Galileo Home Page! The Galileo spacecraft is currently enroute to Jupiter, with arrival scheduled for December 7, 1995. At that time, Galileo's atmospheric probe will plunge into Jupiter's atmosphere, relaying information on the structure and composition of the solar system's largest planet. The spacecraft's orbiter will then spend two years orbiting the giant planet, studying Jupiter and its moons, and returning a steady stream of images and scientific data. NASA's Galileo project is managed by the Jet Propulsion Laboratory (JPL) in Pasadena, California. The Galileo probe development and operations is the responsibility of NASA's Ames Research Center in Mountain View, California.

    If you find that the access to this home page is slow, then try our mirror site at http://newproducts.jpl.nasa.gov/galileo/

    Countdown:
    1 days 14 hours 0 minutes 0 seconds
    until Io Closest Approach (Spacecraft Event Time)!

    Galileo Home Page Menu

    Galileo Amazing Fact of the Day

    Jupiter has no solid surface; it is composed almost entirely of hydrogen and helium and is hot enough inside to vaporize all elements. After the Galileo probes's mission is completed, it will continue to sink into Jupiter until the temperatures reach points that, in turn, cause various parts of the probe to melt and then vaporize.

    More Galileo Amazing Facts

    o What's New (December 5, 1995)

    o Countdown to Jupiter
    Now available! A home page dedicated to Galileo's arrival at Jupiter, with simulated Jupiter approach images, hourly updates, the Galileo spacecraft position updated every minute and more.

    o Latest News on Galileo
    Hot off the press, the latest news on the Galileo mission.

    o Online From Jupiter
    Interested in exploring the solar system, or Jupiter? Curious about what it's like working "behind the scenes" on NASA's Galileo mission? If you have internet access, or even just a phone, you can peek over the shoulders of Galileo's scientists and engineers, and (for K-12 students and teachers) ask them questions! Check out the press release or the nifty handbill for further information.

    The Online From Jupiter question line is now open for business! K-12 students should check out the instructions on how to submit questions.

    o Keyword Search
    Overwhelmed by the information on this home page? You can search our information database for a specific topic about Galileo.

    o Galileo--Mission to Jupiter
    Background material on the mission: spacecraft pictures, timelines, fact sheets, navigation information, and more.

    o Galileo Images
    Images taken by Galileo of asteroids, Earth & Moon and Venus. The new Jupiter images will be stored here as well.

    o Galileo Probe Home Page
    The Galileo Probe team at Ames Research Center has their own home page.

    o Galileo Messenger
    The official newsletter from the Galileo Project.

    o Educational Resources
    Are you a teacher looking for something new for your classroom? A parent with children who are eager to learn about space? Check out the Galileo Education Resources page. Expect lots of updates here over the next two years!

    o Frequently Asked Questions
    How fast is the probe going when it hits Jupiter's atmosphere? Why doesn't Galileo use solar panels? Answers to these and other questions can be found in Galileo's FAQ. And, if you don't find your question answered, submit your own question (we will post and answer 2-3 each month. Recent additions: July 10, 1995, September 14, 1995 and December 5, 1995.

    o Related Home Pages
    Other home pages relating to the Galileo mission.

    Visitor Count Since Jan 18, 1995:

    For questions about content please contact
    JPL Public Information Office
    Phone: (818) 354-5011
    askgalileo@gllsvc.jpl.nasa.gov

    NASA/JPL Logo

    -----------------------------30225321569240-- From director@bcn.boulder.co.us Fri Nov 17 16:27:33 2000 Received: from localhost (director@localhost) by bcn.boulder.co.us (8.9.3/8.9.3/ITS-5.0/bcn) with SMTP id QAA16200; Fri, 17 Nov 2000 16:27:33 -0700 (MST) Date: Fri, 17 Nov 2000 16:27:33 -0700 (MST) From: director To: paul_von_behren@yahoo.com, ptiger@indra.com cc: Jim Harrington , Neal McBurnett , paul.von.behren@computer.org Subject: Mon. 11/20 Town Mtg Planning Mtg POSTPONED Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hello Paul & Paul: Just a quick note to let you know that Monday's planning meeting for the Town Meeting has been postponed as a result of recent discussion by the BCN Executive Committee. They decided that initiative needs to be further discussed in the context of the Executive Director search, the 7th Anniversary fundraiser and related issues before we proceed. Thanks for your willingness to participate, and we will let you know when the meeting has been rescheduled. So now you can go watch Monday Night Football. (; See you around -- Karen, for BCN From ptiger@indra.com Sat Nov 18 00:49:38 2000 Received: from server.indra.com (server.indra.com [204.144.142.2]) by bcn.boulder.co.us (8.9.3/8.9.3/ITS-5.0/bcn) with ESMTP id AAA03068; Sat, 18 Nov 2000 00:49:37 -0700 (MST) Received: from net.indra.com (net.indra.com [204.144.142.1]) by server.indra.com (8.10.1/8.10.1) with ESMTP id eAI7nZv03388; Sat, 18 Nov 2000 00:49:35 -0700 (MST) Received: from cpq (vc1-104-1.adsl.indra.com [206.168.195.63]) by net.indra.com (8.10.1/8.10.1) with SMTP id eAI7nUg13181; Sat, 18 Nov 2000 00:49:30 -0700 (MST) From: "Paul Tiger" To: "director" , Cc: "Jim Harrington" , "Neal McBurnett" , Subject: RE: Mon. 11/20 Town Mtg Planning Mtg POSTPONED Date: Sat, 18 Nov 2000 00:46:18 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Okay by me. As the newly hired Technical Director for the Peak Association for the Arts at the Dairy Center, I'm up to my eyebrows in theatre production work. After December 3rd I'll be coming back up for air. Hope that some of you will bring your children to see the Nutcracker in Boulder on November 24th, 25th, and 26th; or in Longmont on December 2nd or 3rd . Paul Tiger ptiger@indra.com 303-774-6383 voice and messages 303-465-7089 page http://www.indra.com/~ptiger There is nothing so useless as doing efficiently that which should not be done at all. Peter Drucker -----Original Message----- >From: director [mailto:director@bcn.boulder.co.us] Sent: Friday, November 17, 2000 4:28 PM To: paul_von_behren@yahoo.com; ptiger@indra.com Cc: Jim Harrington; Neal McBurnett; paul.von.behren@computer.org Subject: Mon. 11/20 Town Mtg Planning Mtg POSTPONED Hello Paul & Paul: Just a quick note to let you know that Monday's planning meeting for the Town Meeting has been postponed as a result of recent discussion by the BCN Executive Committee. They decided that initiative needs to be further discussed in the context of the Executive Director search, the 7th Anniversary fundraiser and related issues before we proceed. Thanks for your willingness to participate, and we will let you know when the meeting has been rescheduled. So now you can go watch Monday Night Football. (; See you around -- Karen, for BCN