[3554] in java-interest
java-interest-digest V1 #263
daemon@ATHENA.MIT.EDU (java-interest@java.sun.com)
Wed Nov 15 23:24:42 1995
From: java-interest@java.sun.com
To: java-interest@java.sun.com
Date: Wed Nov 15 04:46:05 GMT 1995
Not-Delivered-To: gateway!daves due to 11 Transfer Failure
ORIGINAL MESSAGE ATTACHED
(rmail: Error # 22 ':84:Surrogate command failed', rc = 0)
======= Surrogate command =======
>From java-interest Tue Nov 14 12:31:04 0800 1995 remote from java.sun.com
Received: from java.sun.com by gateway.interdyn.com; Tue, 14 Nov 1995 20:46 PST
Received: (from majordom@localhost) by java.sun.com (8.6.12/8.6.12) id MAA08613 for java-interest-digest-outgoing; Tue, 14 Nov 1995 12:31:04 -0800
Date: Tue, 14 Nov 1995 12:31:04 -0800
Message-Id: <199511142031.MAA08613@java.sun.com>
From: owner-java-interest-digest@java.sun.com
To: java-interest-digest@java.sun.com
Subject: java-interest-digest V1 #263
Reply-To: java-interest@java.sun.com
Errors-To: owner-java-interest-digest@java.sun.com
Precedence: bulk
X-Info: To unsubscribe, send 'unsubscribe' to java-interest-digest-request@java.sun.com
Content-Type: text
Content-Length: 31545
java-interest-digest Tuesday, 14 November 1995 Volume 01 : Number 263
In this issue:
FW: What happend to net.www.html.Parser, Document, Tag and TagRef?
Mid-Atlantic JUG interest.... -Reply
Sun Java Training Schedule
Re: protected is not?
Re: Audio in a standalone application
Re: declaration v.s. definition ambiguity
Re: How java apps get krb tickets?
Java applets and CGI programs
Re: NS/Beta 2:"start: applet not intialized"
Client Server communication
Re: NS/Beta 2:"start: applet not intialized"
Re: NS/Beta 2:"start: applet not intialized"
Transparent Text/Canvas
Re: FW: What happend to net.www.html.Parser, Document, Tag and TagRef?
URL.getContent() - html class?
Introduction to Java - Questions
Re: protected is not?
exec/Process question
Help - Error 4
java threads.
Re: How java apps get krb tickets?
Re: How java apps get krb tickets?
----------------------------------------------------------------------
From: Greg White <gwhite@inetmi.com>
Date: Tue, 14 Nov 1995 09:28:45 -0500
Subject: FW: What happend to net.www.html.Parser, Document, Tag and TagRef?
The alpha 3 release of java had 4 useful classes in the net.www.html =
package that are not there in the Beta 1.0 release of the JDK: Parser, =
Document, Tag and TagRef. =20
I have an alpha 3 (command-line) application that uses these classes to =
parse HTML input. I would like to be able to port it to the Beta 1.0 =
release. =20
What happened to these classes? When I look at the "Changes Since the =
Last Release" documents for both the 1.0 Pre-Beta 1 and the 1.0 Beta, =
these are not mentioned.
I had sent a request for information directly to the java development =
team, but got no response beyond a form letter. I am planning on =
writing some articles about this and would prefer not to have to write =
the HTML parsing routines as I had originally picked Java because it was =
shipped with those routines.
Note: please send any responses directly to me or to the java mailing =
list as I do not java access to the newsgroup.
Greg White I/NET, Inc.
gwhite@inetmi.com
------------------------------
From: "Arthur L. Talley" <talleyal@deca-gw.deca.mil>
Date: Tue, 14 Nov 1995 09:55:48 -0500
Subject: Mid-Atlantic JUG interest.... -Reply
>>Are you interested in attending monthly meetings in the
>>Baltimore/DC-Metro area?
No, I am a central Virginia resident.
>>If yes, what location would be best for you?
Richmond, VA
>>Are you interested in an email support group?
Yes I would really find an east coast based support group very helpful.
>>Are there any particular topics of interest you would like discussed?
I am Lead Developer for a team working on a large scale java
client/server app that uses alot of graphics. I would love to have another
outlet for help if I get stuck on somthing.
------------------------------
From: jazukow@rssi.rssi.com (John Zukowski)
Date: Tue, 14 Nov 1995 10:17:17 -0500
Subject: Sun Java Training Schedule
Someone had posted a request for a list of the Java training classes in
the Boston Sun Ed center (Chelmsford I believe). At the JavaDay West,
there was a schedule of classes provided. Boston had classes the
following weeks:
12/18/95
1/8/96
2/26/96
3/11/96
4/29//95
6/24/96
8/12/96
Beginning of the week is Basic/Intro SL-230, end of week is Advanced SL-270.
Baltimore (Columbia) has classes the following weeks:
11/20
12/18
1/22
2/12
3/4
3/25
4/15
5/6
6/3
7/8
8/26
Dallas
12/4
2/5
4/29
7/8
LA
12/11
4/1
7/22
Milpitas
12/18
1/3
1/29
2/12
3/4
3/25
5/6
6/17
7/1
8/12
New York
11/27
12/11
1/8
2/19
3/18
4/22
5/20
6/17
7/15
8/5
To Register Call 800-422-8020.
Sorry about any typos. By the way, most are already full.
John Zukowski
Rapid Systems Solutions
john.zukowski@rssi.com
http://www.rssi.com
------------------------------
From: Edith Au <edith@pencom.com>
Date: Tue, 14 Nov 1995 10:30:04 -0500 (EST)
Subject: Re: protected is not?
Hi,
protected variables can be accessed by the methods of its class and subclasses
apiece is an object of junk so apiece can access protected variable name.
Change name to a private variable if you want name to be accessed only by
the junk class.
Cheers,
Edith
>
> Here is a simple chunk of code that does not
> seem to work properly.
>
> class junk {
> protected String name;
>
> junk(String inName)
> {
> name = new String(inName);
> }
> }
>
> class Protect {
> public static void main(String args[])
> {
> junk apiece = new junk("piece of junk");
>
> System.out.println(apiece.name);
> }
> }
>
>
> This code compiles and prints out the name of the
> object. The problem is that the compiler should not have
> let me do this. name is a protected variable. protected should
> mean that inaccesible except to subclasses.
>
> Any ideas or is this a bug?
>
> I am using the beta for Win95.
>
> - Mike Daconta
>
> -
> This message was sent to the java-interest mailing list
> Info: send 'help' to java-interest-request@java.sun.com
==============================================================================
Edith Au Tel: (212) 513 7777
WWW Specialist Email: edith@pencom.com
Pencom Systems Incorporated WWW: http://www.pencomsi.com/~edith
40 Fulton Street,
NY, NY 10038
===============================================================================
------------------------------
From: suresh@thomtech.com (Suresh Srinivasan)
Date: Tue, 14 Nov 1995 10:34:54 -0500
Subject: Re: Audio in a standalone application
>
> I've been trying to play audio clips in a standalone Java application
> with little success. It seems the only possible way to do this without
> using anything in the sun.* tree would be to import java.applet.* and
> then do something like:
>
> play(new URL("http://site.com/soundfile.au"));
>
> or
>
> AudioClip clip = new AudioClip;
> clip = getAudioClip(new URL("http://site.com/soundfile.au"));
> clip.play();
>
> Neither of these work, I get errors that Java cannot find getAudioClip()
> and play(). How might I go about doing this? Thanks.
>
> robert
>
Ensure that the URL is the right one and the audio file is there.
I think play() returns silently if the URL is bad.
Then make sure that you've imported all the right classes.
I think you'll need:
import java.applet.Applet;
import java.applet.AudioClip;
There's a trivial example I have that works and might help at:
http://www.thomtech.com/~suresh/java/beta/GuitarMusic.java
Else, show us the exact error message you're getting.
Cheers,
- --Suresh
------------------------------
From: "R.Volkmann" <m224873@svxtrm14.mdc.com>
Date: Tue, 14 Nov 1995 09:39:53 -0600
Subject: Re: declaration v.s. definition ambiguity
>Date: Mon, 13 Nov 1995 09:32:41 -0700
>From: garya@village.org (Gary Aitken)
>
>It would be really
>nice if /** comments in the code could be preserved in the .class file (new
>option for javac?), and output by javap. One could then program in a style
>which allowed shipping a .class file from which javap could extract a
>reliable, well documented api.
I'm new to Java. Why would you want to use a /** comment instead of //?
Does it do something different? How does /** differ from /*?
|----------------------------------------------------------------------------|
| R. Mark Volkmann - Principal Specialist Programmer/Analyst |
| McDonnell Douglas Aerospace, St. Louis, Missouri, USA |
| EMAIL m224873@svmstr01.mdc.com, VOICE (314)232-0498, FAX (314)233-5489 |
|----------------------------------------------------------------------------|
"As the light changed from red to green to yellow and back to red again,
I sat there thinking about life. Was it nothing more than a bunch of
honking and yelling? Sometimes it seemed that way." -- Jack Handy
------------------------------
From: "Larry S. Bartz" <lsbart35@emmo.indy.cr.irs.gov>
Date: Tue, 14 Nov 1995 11:27:42 -0500 (EST)
Subject: Re: How java apps get krb tickets?
On Sat, 11 Nov 1995, Adam Cain wrote:
> Date: Sat, 11 Nov 1995 13:52:55 -0600
> From: Adam Cain <acain@snapple.ncsa.uiuc.edu>
> To: java-kerberos@lists.Stanford.EDU
> Subject: How java apps get krb tickets?
>
> First, to address a previous question/concern:
>
> The Kerberized Mosaic certainly does check the ticket cache before
> it asks for a kerberos password. Obviously, we put in the capability
> to klogin from within Mosaic so that things are easier to use, especially
> for the somewhat kerberos-naive user. We feared that simply displaying
> a message like "sorry, you must klogin to get a TGT" and then expecting
> the user to go off into some other shell to do "kinit" might be considered
> too laborious or cryptic by "normal" users. Yet, I can certainly appreciate
> the spirit of keeping the password/TGT functions only in kinit/klog. I'll
> discuss this also with people on the www-kerberos list and if enough people
> object to this feature (really, we worked hard on this particular "bug"),
> then we'll take it out.
Take it out?
Don't you dare! Your initial notions on this subject are the correct ones.
We'll never be able to implement the Kerberized Web if we make it too
clunky for Joe Average User. A large part of the beauty of putting our
applications up on the Web (and kerberizing the authentication and
authorization) is that we are providing the potential for unprecedented
levels of wide scale integration; making the matrix (uh, the Web) look
like it is "all one thing" to our customers.
There is tremendous value in this integration. Anything which detracts
from it will naturally detract from its potential beauty (for us), and
its usability (for our customers).
Adam continued:
>
> But back to the orginal question of how the kerberized java app gets
> its tickets. Let me summarize my understanding of the last couple notes
> from Mark and Roland, with respect to this question (and again, please
> forgive my relative unfamliarity with the details of java's security
> mechanisms). It seems there are two basic approaches for this:
>
> 1. The java applet could get the user's kerberos password and then get a TGT.
> From that point on, it gets its own tickets from the KDC, as needed.
>
> 2. The java applet could get tickets using the user's ticket cache. Assuming
> the cache has a TGT, the applet can also get tickets from the KDC.
>
> As Mark mentioned, #1 makes security people nervous, as it is quite risky and
> somewhat contrary to the intent of kerberos.
>
> As for #2, Roland points out that the applet probably can't (and should not
> be able to) access the user's ticket cache.
Ken Arnold (addressing an unrelated issue for the java-interest@java.sun.com
list members) also drives Roland's point home. This point was
also described by David R Richardson <normanb@citi.umich.edu> for the
java-kerberos list last week. Because the applets are not allowed to load
native methods, #1 will be the only way to go.
So the java kerberos applet can't share its ticket cache with other apps?
Tough applets, I say; a small price to pay.
>
> I also wonder about the applet's abililty to cache tickets -- can it save to a
> file, or must it keep everything it needs in memory? Also, what does the
> user have to do in order to allow java applets to open their own network
> connections (for getting a ticket from the KDC)?
I'd prefer to see the cache simply in applet-managed memory. This way,
it wouldn't conflict with any other cache and they'd go away
when the user terminates the browser session without requiring any
other explicit kdestroy action on their part.
>
>
> Of these two approaches, I don't see one as being clearly superior to the
> other. In either case, the user probably will (and should) have to make
> an acknowledgement of trusting the applet before it can do anything with
> kerberos. With #2, there would probably be some explicit mechanism for
> granting the applet access to the user's ticket cache. For #1, the user is
> putting significantly more trust in the applet (by giving it the kerberos
> password), though there may be ease-of-use reasons for doing it this way.
>
>
Yes, certainly the ease of use issue is important. Else, why would we
bother adapting our applications to the Web? Else, why would we bother
to use Kerberos to provide a "single login" access to multiple services?
- --
#:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::|
# Larry Bartz | |
# lbartz@infostream.cr.irs.gov | Ooo, ooo, |
# | Ooo, ooo, oooooo! |
# | I've got a gnu attitude! |
# voice (317) 226-7060 | |
# FAX (317) 226-6378 | |
#:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::|
------------------------------
From: max@mercury.co.il (Maxim Kholmyansky)
Date: Tue, 14 Nov 95 18:24:55 IST
Subject: Java applets and CGI programs
Hi,
I am new to Java, and my question is whether this language
can help me to write Web applications which collect some
data from the client, and process/store it in the server.
The only way known to me for this task is to submit a form,
and to process its results by executable written according
to CGI.
Unfortunately, all the appletes demos I was able to find made
the processing on the client side, but didn't send any information
to the server.
I can't send everything to the client - think about large database!
Is there anything in Java that can help to solve such problems?
Any pointers will be highly appreciated.
Thank's in advance,
Max.
===========================
Max Kholmyansky
Software Developer
Mercury Interactive Israel
E-mail: max@mercury.co.il
Phone: (+972)-3-5388840
Fax: (+972)-3-5331617
==========================
------------------------------
From: "R.Volkmann" <m224873@svxtrm14.mdc.com>
Date: Tue, 14 Nov 1995 10:28:25 -0600
Subject: Re: NS/Beta 2:"start: applet not intialized"
>Date: Mon, 13 Nov 1995 12:02:25 -0500
>From: Steve Azueta <azueta@lennon.sonicnet.com>
m
>
>Troy says...
>
>> I've had trouble getting NetScape 2.0b2 to run applets. All of my
>> applets ran fine under the 2.0b1 version, but the second beta version
>> just doesn't want to run them. Gives me all sorts of complaints.
>> (BTW, my CLASSPATH points to the moz2_0.car dir, and I updated this
>> file to the new moz2_0.car file.)
>
>I had the very same trouble with Netscape 2.0b2 on Solaris 2.4. Here's
>what I found:
>
>Specifying the moz2_0.car directory path is NOT good enough for Netscape
>2.0b2. Your CLASSPATH must specify the full path of the file. AND it
>needs to be the FIRST path in CLASSPATH. Like so:
I downloaded the JDK for Solaris but I don't have a file called moz2_0.car.
Where do I get it. Apparently I can't run Java applets from Netscape 2.0
without it.
|----------------------------------------------------------------------------|
| R. Mark Volkmann - Principal Specialist Programmer/Analyst |
| McDonnell Douglas Aerospace, St. Louis, Missouri, USA |
| EMAIL m224873@svmstr01.mdc.com, VOICE (314)232-0498, FAX (314)233-5489 |
|----------------------------------------------------------------------------|
"As the light changed from red to green to yellow and back to red again,
I sat there thinking about life. Was it nothing more than a bunch of
honking and yelling? Sometimes it seemed that way." -- Jack Handy
------------------------------
From: "Ka-Fai Lau(MS)" <klau01@widelux.poly.edu>
Date: Tue, 14 Nov 1995 11:54:19 -0500 (EST)
Subject: Client Server communication
Hi, I get a question about how does a class ServerSocket write and read
data from the class Socket? And for the class Socket, I do not know how
to use the method getInputStream and getOutputStream properly? I read
the file which I download from the net, it does not give me much
information. The file is in /java/apidocs/java.net.Socket.html#_top_.
I am using JDK 1.0 beta version which runs on Solaris.
Thanks for your attention.
------------------------------
From: "R.Volkmann" <m224873@svxtrm14.mdc.com>
Date: Tue, 14 Nov 1995 10:45:39 -0600
Subject: Re: NS/Beta 2:"start: applet not intialized"
I'm having problems getting an applet to run in Netscape 2.0 on HP-UX.
I have the CLASSPATH environment variable set to contain the
moz2_0.car location and the location of the JDK classes as follows
export CLASSPATH=/directory/Netscape/moz2_0.car:/directory/Java/JDK/classes
(This is ksh syntax.)
Can I run the demo files from Netscape by entering a URL like
file://localhost/home/volkmann/Java/JDK/demo/MoleculeViewer/example3.html ?
When I try this I get lots of error message lines. The first is
at netscape.netURLConnection.connect(URLConnection.java:70)
Any ideas?
|----------------------------------------------------------------------------|
| R. Mark Volkmann - Principal Specialist Programmer/Analyst |
| McDonnell Douglas Aerospace, St. Louis, Missouri, USA |
| EMAIL m224873@svmstr01.mdc.com, VOICE (314)232-0498, FAX (314)233-5489 |
|----------------------------------------------------------------------------|
"As the light changed from red to green to yellow and back to red again,
I sat there thinking about life. Was it nothing more than a bunch of
honking and yelling? Sometimes it seemed that way." -- Jack Handy
------------------------------
From: Steve Azueta <azueta@lennon.sonicnet.com>
Date: Tue, 14 Nov 1995 12:01:25 -0500
Subject: Re: NS/Beta 2:"start: applet not intialized"
>>>>> "R" == R Volkmann <m224873@svxtrm14.mdc.com> writes:
R> I downloaded the JDK for Solaris but I don't have a file called
R> moz2_0.car. Where do I get it. Apparently I can't run Java
R> applets from Netscape 2.0 without it.
Pardon this Netscape interruption into the java-interest list, but allow
me to clarify a bit...
moz2_0.car is a file that comes with/from Netscape. It is only needed
by Netscape so that Netscape can run java applets. I have no idea what
this file actually is or does, but it's a Netscape thing -- it comes with
the Netscape (UNIX) browser distribution from Netscape.
Netscape introduced a bug into itself (at least in 2.0b2 for Solaris 2.4)
where it needs to have the comlete file path specified as the 1st item
in CLASSPATH. (CLASSPATH=/usr/classes/moz2_0.car works,
CLASSPATH=/usr/classes doesn't work -- this is in Solaris 2.4.)
JDK -- from Sun -- in itself, has NOTHING to do with moz2_0.car. BUT,
javac (the java compiler from Sun) breaks when it finds a complete file
path in CLASSPATH. JDK *doesn't* require moz2_0.car, but the fact that a
file (versus a directory) is in CLASSPATH makes javac fail. Thus java
development and Netscape-java-browsing don't work when initiated from
the same shell. (Did I say that this is in Solaris 2.4? ;-))
Hope this helps.
steve.
- --
Steve Azueta
azueta@sonicnet.com
------------------------------
From: William Cook <william@luma.com>
Date: Tue, 14 Nov 1995 09:02:26 -0800
Subject: Transparent Text/Canvas
Let me refine my question some more. What I really need is to be
able to draw "transparent text". That is, text that only draws the
characters, but does not fill in the background. There are other
Components under the text component, and I don't want to do anything but
put text on top of them.
I am drawing my text using a subclass of Canvas. I am making
direct calls to the Graphics drawing routines. However, it seems that
my canvas is being painted with a background color first, even
though I override update(). Is there any way to prevent this?
I am using the Beta APIs on WindowsNT.
- -william
------------------------------
From: Arthur.Vanhoff@Eng.Sun.COM (Arthur van Hoff)
Date: Tue, 14 Nov 1995 09:36:30 -0800
Subject: Re: FW: What happend to net.www.html.Parser, Document, Tag and TagRef?
Hi Greg,
> The alpha 3 release of java had 4 useful classes in the net.www.html
> package that are not there in the Beta 1.0 release of the JDK: Parser,
> Document, Tag and TagRef.
These are sun specific classes and won't be in future releases.
> I have an alpha 3 (command-line) application that uses these classes
> to parse HTML input. I would like to be able to port it to the Beta
> 1.0 release.
A Java HTML parser available in:
ftp://java.sun.com/pub/java/avh/html.tar.Z
It needs more work.
> What happened to these classes? When I look at the "Changes Since the
> Last Release" documents for both the 1.0 Pre-Beta 1 and the 1.0 Beta,
> these are not mentioned.
> I had sent a request for information directly to the java development team,
> but got no response beyond a form letter. I am planning on writing some
> articles about this and would prefer not to have to write the HTML parsing
> routines as I had originally picked Java because it was shipped with those
> routines.
HotJava will contain better documented APIs for HTML support.
Have fun,
Arthur van Hoff
------------------------------
From: nataraj@cat.syr.edu
Date: Mon, 13 Nov 95 17:21:08 EST
Subject: URL.getContent() - html class?
Hi,
I am trying to understand/use the getContent() method in the URL class.
The code snippet is as follows:
URL myURL = new URL("http://www.cat.syr.edu/~nataraj");
URLConnection myConn = myURL.openConnection();
:
:
Object obj = myURL.getContent();
But when this is compiled and run, it executes this "getContent()"
statement and gives the following error:
java.lang.ClassNotFoundException: sun/net/www/content/text/html
at java.net.URLConnection.getContentHandler(URLConnection.java)
at java.net.URLConnection.getContent(URLConnection.java)
at java.net.URL.getContent(URL.java)
at Urlfun.main(Urlfun.java:30)
The contents is html ...but the classes under the sun/net/www/content/text are
plain and Generic and I couldnt find the html.class in that class directory.
If there doesnt exist a html.class, why is it being searched for?
What should I do? ANy pointers/ideas are appreciated.
thanks,
- - -Nataraj
(nataraj@cat.syr.edu)
------------------------------
From: alfv@xetron2.xetron.com (Alfonse Thinh Vu)
Date: Fri, 10 Nov 95 12:05:24 EST
Subject: Introduction to Java - Questions
Hi,
I became interested in Java while surfing the Web and I have no experience/knowledge about this language. I'd like to explore it and I may ask some very silly questions, based on what I know about C/C++, before I start investing time and money in it. My questions are:
(1) Can I use Java to write code where I used to, using C/C++. For example, I would like to use Java to write GUI applications much like using XView/Motif, or even using Java in Windows on PC.
(2) Do we do the same in Java as in C/C++: Get a Java compiler with necessary libraries, write Java code, compile, link to the libraries, then execute the program? Does JDK have all of these?
(3) Does anybody think that Java might be useful outside the Web world? Is it still advisable to use Java if I am not programming for Web?
(4) Is there any report/review about Java, esp comparing it with C/C++? I *heard* that the interpreter is *very* slow. Is it? If portability is not of concern, how about the compiler?
(5) And more questions in the future.
Thanks to all of you who take time to read or/and respond. Please bear with me.
Alphonse Vu alfv@xetron.com
------------------------------
From: arnold@cocolat.East.Sun.COM (Ken Arnold - Sun Labs)
Date: Tue, 14 Nov 1995 13:04:03 -0500
Subject: Re: protected is not?
"protected" means that only extended class *and* other classes within
the same package can access the identifier. Packages in the same class
are considered to be, well, "friendly". This is one reason it is
important to package your classes correctly
Ken
------------------------------
From: dave@ipac.caltech.edu
Date: Tue, 14 Nov 1995 10:18:23 -0800 (PST)
Subject: exec/Process question
Greetings. I want to use Java to provide an interface to an existing
application. My thoughts so far are as follows: use System.exec to start
the application, which should hand me a Process object implementing an input
and output stream for the application's stdin and stdout. I am running
Solaris 3.4.
The trouble is I haven't gotten this to work. No matter what application I
try to start, even standard system ones, I get a segv and core dump from the
application (the Java task continues merrily on).
This must be a fairly standard thing to do, does anyone have some code
examples or kind words of advice they could send my way?
Cheers,
Dave Van Buren (dave@ipac.caltech.edu)
------------------------------
From: "Patrick H. Nadeau" <nadeaup@pcnet.com>
Date: Mon, 13 Nov 1995 22:49:42 -0500
Subject: Help - Error 4
Directory of C:\java\demo\nervoustext
10/13/95 02:54a 1,513 NervousText.java
10/13/95 02:54a 2,231 NervousText.class
10/13/95 02:54a 183 example1.html
C:\java\demo\nervoustext>javac nervoustext.java
nervoustext.java:12: Warning: Public class NervousText must be
defined in a file
called "NervousText.java".
public class NervousText extends java.applet.Applet implements
Runnable {
^
1 error
I set my path to -> PATH=c:\java\bin
Anyone know why I am getting this?
I did not have this problem with Alpha3.
I know it is something stupid, but..... I guess I am...
------------------------------
From: "Cristini, Jamie" <Cristinij@segaoa.com>
Date: Tue, 14 Nov 95 11:56:00 PST
Subject: java threads.
I'm a newbie to java and I hope someone can help me out. From the
questins I've seen asked and answered here, I think this is an easy one.
Let's say I would like to make an object that that animates a series of
images in an applet. I want to be able to tell it how many images to
load and the x y coordinates where it should appear. Each animations
should have it's own thread. Here's where I get confused.
I make my animation applet then I need to make a constructor so I can
call the class with the coordinates.
public class animate extends Applet implements Runnable {
public animate(int numberimages, int imgx, int imgy)
{
nimgs = numberimages;
x = imgx;
y = imgy;
}
(other code)
}
I then make my main function to create the seperate threads(I think).
This is where I get my errors. I'm not sure what I'm doing wrong.
class testanimate
{
public static void main(String args[])
{
new animate(8, 10, 10).start();
new animate(16, 10, 10).start();
}
}
2nd Question from the applet which class do I call?
I've tried both but they both give errors.
Thanks in advance,
Jamie
------------------------------
From: Mark Eichin <eichin@cygnus.com>
Date: Tue, 14 Nov 1995 15:06:18 -0500
Subject: Re: How java apps get krb tickets?
> Yes, certainly the ease of use issue is important. Else, why would we
> bother adapting our applications to the Web? Else, why would we bother
> to use Kerberos to provide a "single login" access to multiple services?
If you have the java app prompt for a password and get it's own non
cached tickets, you've eliminated the entire single-signon aspect of
kerberos... unless, of course, you expect that users will *only* be
using kerberos through this java app; do you? Or are they just going
to have to give eudora their password again because the cache isn't
shared? (It also ignores forwarded credentials in V5, but presumably
the user is running the app locally anyhow...)
_Mark_
------------------------------
From: Drew Dean <ddean@CS.Princeton.EDU>
Date: Tue, 14 Nov 1995 15:30:11 -0500
Subject: Re: How java apps get krb tickets?
From: "Larry S. Bartz" <lsbart35@emmo.indy.cr.irs.gov>
Subject: Re: How java apps get krb tickets?
Date: Tue, 14 Nov 1995 11:27:42 -0500 (EST)
> On Sat, 11 Nov 1995, Adam Cain wrote:
>
> > Date: Sat, 11 Nov 1995 13:52:55 -0600
> > From: Adam Cain <acain@snapple.ncsa.uiuc.edu>
> > To: java-kerberos@lists.Stanford.EDU
> > Subject: How java apps get krb tickets?
> >
> > First, to address a previous question/concern:
> >
> > The Kerberized Mosaic certainly does check the ticket cache before
> > it asks for a kerberos password. Obviously, we put in the capability
> > to klogin from within Mosaic so that things are easier to use, especially
> > for the somewhat kerberos-naive user. We feared that simply displaying
> > a message like "sorry, you must klogin to get a TGT" and then expecting
> > the user to go off into some other shell to do "kinit" might be considered
> > too laborious or cryptic by "normal" users. Yet, I can certainly appreciate
> > the spirit of keeping the password/TGT functions only in kinit/klog. I'll
> > discuss this also with people on the www-kerberos list and if enough people
> > object to this feature (really, we worked hard on this particular "bug"),
> > then we'll take it out.
>
> Take it out?
> Don't you dare! Your initial notions on this subject are the correct ones.
From a user's point of view, I agree 100%. However, I think it would
be better for this to be built in to the browser, and not a Java
applet, to make it harder to spoof this dialog. (That is, this dialog
needs to be a trusted path to the authentication code.)
> Adam continued:
> >
> > But back to the orginal question of how the kerberized java app gets
> > its tickets. Let me summarize my understanding of the last couple notes
> > from Mark and Roland, with respect to this question (and again, please
> > forgive my relative unfamliarity with the details of java's security
> > mechanisms). It seems there are two basic approaches for this:
> >
> > 1. The java applet could get the user's kerberos password and then get a TGT.
> > From that point on, it gets its own tickets from the KDC, as needed.
> >
> > 2. The java applet could get tickets using the user's ticket cache. Assuming
> > the cache has a TGT, the applet can also get tickets from the KDC.
> >
> > As Mark mentioned, #1 makes security people nervous, as it is quite risky and
> > somewhat contrary to the intent of kerberos.
> >
> > As for #2, Roland points out that the applet probably can't (and should not
> > be able to) access the user's ticket cache.
I meant to reply to this message, but never got around to it. I think
I see a real problem with #1, at least for multi-user machines.
Forgive me for a lack of Kerberos knowledge, but if I recall
correctly, if I can login to your machine, and I have your TGT, then
Kerberos will authenticate me as you. If this is how life works, I
wouldn't let a Java applet get a TGT for me because anything a
Java applet learns it can leak, as the Java runtime system has _not_
been analyzed for covert channels (at least acccording to any
documents I've seen), and there are tons of them. It would take a lot
of work to build a Java-enabled browser, running on a multi-user OS,
that I'd trust to make a TGT available to an applet.
Drew Dean
<ddean@cs.princeton.edu>
------------------------------
End of java-interest-digest V1 #263
***********************************
-
This message was sent to the java-interest mailing list
Info: send 'help' to java-interest-request@java.sun.com
