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Technical
Support : General FAQ
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System Requirements:
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Java is supported by Netscape versions 2 and
higher, MS Explorer versions 3 and higher, HotJava and other
browsers, on 32 bit operating systems (Windows 95/NT, Mac
OS, Sparc, Linux, etc.). Java applets will not appear on Windows
3.1, or on a 16 bit browser (Netscape 4 for Win 3.1 supports
Java but not as well as on Win 95). The Java support should
be enabled in the browsers too, otherwise you will see a message
stating your browser does not support Java.
The Anfy wizard requires Win 95/98/NT.
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Differences between
Java and Javascript |
Java is different from JavaScript: Java is
made by creating .class files and is more powerful than JavaScript
(which is a script/batch language written directly inside a
.html document). The Anfy package contains only Java applets.
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How to add Java applets
to html documents: |
1)
Copy the .class files to the same dir as the .html files, along
with any GIF and JPG images. In Anfy wizard this can be
done with the "Copy all files to" function.
2) Add the <applet> tag in the html document.
Some html editors do not allow this or have special standards.
If this occurs, save the .html file first, then edit it with
dos edit, notepad or another ASCII text editor. Then manually
add the <applet> tag.
Anfy wizard helps you create the <applet> tag with
the right parameters for your purposes and your images, but
you still have to copy and paste the resulting <applet>
tag in your html document. You can use the "Copy all files
to" function to save an html document that contains only
the applet, and then re-open it with your preferred html editor
to add what you want.
3) Upload the .html file, .class files and any others
(images etc.) to your web page directory as usual.
Please note that you have to upload the .class files using FTP
in BINARY mode and not in ASCII mode !! Otherwise the applets
will not work (a "java.lang.ClassFormat" or
"java.lang.MethodVerification" or "Bad
Magic Number" error message will be displayed).
Be sure file names and file lenghth is not changed during upload
process: if files are of different size, or have different name
(for example ends with .cla instead of .class) something went
wrong. |
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Most common errors:
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A) LONG
FILENAMES TRUNCATION AND LETTER CASE CHANGE: Many MS-DOS
users are still using PKUNZIP to decompress zip archives or
16 bit programs to copy and upload files, and do not take into
consideration the difference between FiLe.ExE, FILE.EXE and
fILe.eXe. This is not good for various reasons:
The first one is the use of long file names: msdos (and
old 16 bit win 3.1 programs) are only able to support file names
with 8+3 characters.
Newer systems on the other hand support long file names, for
example MyNiceApplet.class, which has a suffix of 5 chars. If
you use PKUNZIP to unzip the applet archives, or upload the
.class files on the server with an old Windows 3.1 FTP program
or similar, you will TRUNCATE the filename, and the result will
be MYNICEAP.CLA !
Trying to run the applet will result in a "java.lang.ClassNotFound"
error displayed. Ensure you unzip using "winzip 32"
or similar in win95, and to copy/upload the files with these
newer programs that do not truncate the filenames.
Consider the case of the characters as well since many servers
on the Internet (Unix) are case sensitive.
For example, if the applet is named "MyNiceApplet.class"
and you write "Myniceapplet.class", the applet will
not work. The most common mistakes are in mismatched image filenames,
because win95 is not case sensitive and it loads an image even
if the case is different.
For example, if you save an image as "image1.jpg"
you will also be able to load it from your local harddrive if
you refer to it as IMAGE1.JPG, image1.JPG or IMAGE1.jpg. But
once you put it on your ISP's server it will only work if you
refer to it as image1.jpg.
Ensure the names of images you load from an applet are identical
in case and characters.
B) Wrong image or applet size: read the instructions
for the applet carefully because images usually MUST be of fixed
sizes (for example 64*64, 128*128 etc.). Do not enlarge the
applets too much, and images more than a width of 600 pixels,
will not be fully visible to those using a video mode of 640*480
pixels.
In most cases, Anfy wizard can detect an incorrect image
or applet size, and this will help prevent one of the most common
errors. |
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Less common errors:
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A) "Using
Netscape Gold 3, the applets work offline but fail to work online,
displaying a java.lang.NullPointerException error."
This is a bug in the browser that randomly appears. If this
occurs, try reloading, clearing the cache, or in rare cases
deleting the cache files manually from netscape cache directory.
Similar "NullPointer" error messages happen occasionally
on Netscape 4.04.
However, visitors will have no problems seeing the applet.
B) "I updated all the class files on my GEOCITIES
site, and when I reloaded the page I got an error message (java.lang.NoClassDefFoundException)
in applets".
This is a temporary problem generated by Geocities and some
other sites. If you reload the page after a couple of minutes,
the applets will run correctly.
In other circumstances, this error means you forgot to upload
some .class files (for example anfy.class).
C) "Using Netscape 3, I got an error message (java.awt.image.Memory
ImageSource: method newPixels(), or java.lang.NoSuchMethodError:
java.awt.image. Memory ImageSource) in applets".
This is a problem related to anfy.class: probably you are using
an old or incorrect anfy.class file, or you have in cache an
old one.
Check if you are using the same anfy.class that comes with the
applets, and clear the caches.
D) "I am using the AOL browser, and everything
else on page would appear but the applet. Instead there was
a message -Loading image-, and the image never appeared, just
a gray rectangle".
In this case, you have to turn off graphics compression in the
AOL internet browser preferences as follows:
On the AOL Toolbar, click Members, Click Preferences, Click
WWW Icon (Picture of world globe), and you will see a dialog
box. Click the "Web Graphics" tab, and a page appears
with the question "Do you want Web Graphics to be compressed.
This will display pages faster"; under the question is
a box that you "check" if you want compression, otherwise
leave it blank. If it is checked, clear it.
E) "I am using a transparent gif image in
one applet (lens, water, lake, etc.) as main image, and
I see gray background instead of transparency".
This is because transparent background is not supported in
Java. You can use transparent images ony as overlay images.
F) Strangely, sometime the GIF overlay images are
not draw totally by Netscape, when are draw ok on Explorer.
In most cases, you just have to re-save the GIF image in interlaced
mode if it was in normal mode, or vice-versa, then it is
displayed correctly.
This problem is more frequent on larger images.
G)"I try to put the applets on my ANGELFIRE
site, but i'm not able to run them, or I'm not able to copy anfy.class
On angelfire by default all the .class files are uploaded in the /images directory,
to run the applets properly angelfire users must add the codebase tag into the html source:
"<applet codebase="images" code="nameofthe.class" width=xxx height=xxx>"
Angelfire in the beginning does not allow to copy the anfy.class in the standard mode.
You need to use the Angelfire FTP option to load the anfy.class file to the server.
H) "I removed the <param name="credits"
parameter, and applet is not running any more, even if it is
registered".
With registration, you purchase a regcode that enables link
parameters and removes the credits window that pop ups when
applet is clicked. This does not includes the "credits"
parameter: it is only a signature of the applet, not visible
by the visitors (except who looks at page source code), this
is why is not modified by registration. Why you want remove
it? As written in instructions, it's unremovable.
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Tips & Tricks:
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1)
You may be thinking, "What will people without Java
browsers see instead of the applet ?" You can specify
an alternate text, image, or a whole html segment to be used
instead of the applet:
<applet code="MyApplet.class" width=150 height=150>
<param name=param1 value="1234">
<param name=param2 value="5678">
<IMG ALT="*" ALIGN=center SRC="alternateimage.gif"
border=0>
</applet>
You can even load images for applets from a cgi-bin/ dir, maybe
a 'pic of the day' cgi or similar:
<applet code="MyApplet.class" width=150 height=150>
<param name=image value="/cgi-bin/Image.cgi">
<param name=param2 value="5678">
<IMG ALT="*" ALIGN=center SRC="/cgi-bin/Image.cgi"
border=0>
</applet>
So, you can display a normal image if Java is not present, rather
than manipulations of the image if Java is present. In
the Anfy wizard, you can enter this alternate text or html
in the "For no Java browser" field.
2) If you want to read .class files from another dir or path,
just use the codebase tag:
<applet codebase="http://www.app.com/app/"
code="MyApplet.class" width=150 height=150>
<param name=param1 value="1234">
<param name=param2 value="5678">
Sorry, your browser doesn't support Java.
</applet>
3) When you try to use a mask for applet, there is a
thin (about 1-2 pixel) border at the top of the applet before
the round image:
To remove it, use the HSPACE="0" and VSPACE="0"
tags, within the <applet> tag:
<applet code="MyApplet.class" hspace=0 vspace=0
width=150 height=150> |
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Frontpage users:
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Here is an example of the configuration steps
for the Anfy Water applet:
1) If you don't already have an image, use Image Composer
( FrontPage's Tool ) to create and save an image as "water.gif"
for example, in a new empty folder.
2) In the Anfy wizard main screen, select WATER,
press the NEXT button, then press "browse" button
and choose your image for the effect. Then press the NEXT button
4 times, and use the publish function "Copy all files
to" to save all the needed files in the new folder.
3) Open FrontPage: In FrontPage Explorer, import
the Java Applets, including anwater.html, anfy.class, AnWater.class
, Lware.class, and waterscr.txt. In other words, these files
must be present in same folder (directory) as the html document
you will edit.
4) In FrontPage Editor, open anwater.html, then select
the applet and click copy button on the toolbar.
5) Open a new web page, or the document where you want
to insert the applet, and click the paste button on the
toolbar.
A faster way would be:
4) Open FRONTPAGE.
5) Open the web you want.
6) Drag the file to the open web
7) Click on the web page within editor will open with
the applet in place, and you can go about editing. Click on
the JBAR in the applet to adjust the settings.
This should configure the applet to work. If you want to change
parameters, double click the applet, and you can open "Java
Applet Properties" box.
You may have directory problems on the server, because FrontPage
requires a web server and forces you to import the .class libraries
onto the web.
If you copy them into the web directories, then you have to
put them in the right place and select "Recalculate Hyperlinks"
in the explorer. Then you have to make sure the applets parameter
point to the applet properly.
Note: to change the scrolltext, you have to modify the waterscr.txt
content |
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Bug reports:
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Some browsers ( particularly Netscape ) cannot read
certain GIF and JPG files in Java applets.
The Java Console will indicate which file(s) are causing the problem.
You can solve this problem by re-saving the file in another
application.
Paint Shop Pro seems to write standard images that do not create problems.
And be sure to name the image without spaces inside.
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Don't save .JPG images from Adobe PhotoShop 4 with "thumbnail"
option enabled, because some Java implementations (Netscape
3) will not be able to read them. Disable thumbnail feature
or use PhotoShop 3.
- MS Explorer 3.02 (and some beta 4.0 versions) have
a bug that causes a exception: com.ms.applet.Security.Couldn`t
connect when Java loads images from the local Hard Disk.
Applets will work when you are online, but will be hard to test
offline, so get a newer or older version (3.01 or 4.0 final
for example).
The URL for Java explorer upgrade is http://www.microsoft.com/java/vm/vmdownload.htm.
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Compatibility parameters:
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PREFACE: Many people think
Java is dangerous, not secure, and crashes a lot of browsers.
This is true for poorly programmed applets and pages overloaded
with 10 applets, and on old computers.
If you use Anfy applets with "Optimize for compatibility"
settings, placing NO MORE than one applet each html page, no
browsers will have the opportunity to crash.
What do I do if the Java applet(s) uses 100% of my CPU power,
slows down the browser, or steals all my available memory ?
A) When the applet is running, Netscape or Explorer may
slow down, and sometimes the Operating System (Win95, WinNT,
MacOS etc.) hangs or slows down as well.
If this happens you have to increase the MinSYNC parameter
until the system operates normally. This value is usually set
to 10, but you can set it to 20,40,60,100 or even more to lower
the applet speed and thus leaving CPU power to the browser and
OS. You can also decrease the "priority" parameter.
B) When the applet has been running for some seconds
or minutes memory runs out and the hard disk starts spinning
(the OS is using it's swap file to simulate more memory).
If this happens, you are most likely using a version of Netscape
3 / MS Explorer 3 w/bugs. This problem is not present in the
fixed rel. 3 and rel. 4, but you can fix the problem by decreasing
memdelay to 10 - 16:
Anfy wizard provides 3 predefined settings in the expert
mode panel: Standard settings will set MinSYNC to 10
and priority to 3, and this is acceptable for 99% of browsers.
If you want to ensure the applet will run even in bugged versions
of Explorer and Netscape and you don't care if the applets run
much slower, select the Optimize for compatibility option.
This will set MinSYNC to 30, priority to 1 and memdelay to 15.
If you want to pump the applets to the max, and don't care if
this will hit older browsers and slow their CPU dramatically,
select Optimize for speed. This places a MinSYNC value
of 2 and a task priority of 6.
It is possible to manually set MinSYNC to 0 and priority to
10, for those who want to test the applet in full speed on a
P200MMX or Pentium II.
Remember, the most important guideline: |
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DON'T INSERT
MORE THAN ONE APPLET ON EACH PAGE |
If you really MUST place more than one applet
per page (do so at your own risk!), be sure to set the priority
parameter to 5 on all applets. If you want one to rung faster
than another, change their priority to match your desired speeds. |
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You have another problem?
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If you are a registered Anfy user
(in other words: if you purchased almost one regcode) and you
are experiencing a technical problem not described in this document,
you can ask freely for help to Anfy
Contact Persons.
Note: the free support (in english only) is guaranteed
only to registered users and, please, be sure
to read well the PROBLEMS SOLVING FAQ, then you will not need
to ask something already answered. |
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