How to add Java Applets to Your Web Page
Q
I have been trying to add applets to my web page and have been using Anfy.
I uploded the things (example:lake effect) and I uploaded the lake class script, and image and everything (because it said instead of publishing it you can copy files to)
Then I kept them on my desktop and uploded them and then tried to apply it.
It keeps saying lake class not found or java lang null or something like that and I was wondering if you can help me and point me in the right direction.
A
I think you need to take a moment to step back and figure out exactly what you are doing.
Adding Java Applets to your page is actually fairly simple, but there are several steps involved and if you make a mistake at any one step because of a misunderstanding (or even a typo) the whole shebang could fail.
Then you are left with an error message and an evening's worth of figuring out where it went wrong.
So let's review the steps necessary to get an applet working on your page and then you can compare this against what you have done.
Hopefully, it will be enough for you to spot the problem.
- Find an applet you like on the web.
- Download the applet files.
- Download the documentation provided by the author (often called README).
- Read the documentation.
- If the applet is distributed in a compressed form (like .zip or .tar), use WinZip to uncompress them. PAY THE SHAREEWARE LICENSE FOR WINZIP.
- After the applet is unzipped, you should have a bunch of .class files, an HTML file, supporting files (like images), and hopefully the JAVA source code in .java files.
- Put those files in a directory that can be accessed by the web (like other HTML pages on your website.
- Open the HTML file and find the <APPLET> tag.
- Follow the instructions in the documentation and modify the <APPLET> tag as instructed.
- Try to run the applet using a web browser.
- If you get a 404 Not Found error, you need to make sure the applet is in the right right directory : )
- If the error is "Class Not Found" it is likely that you have not placed the .class files in the same directory as the Java Applet that references them or they are in a subdirctory that does not reflect the <APPLET> tag.
- If you get the HTML with a blank box where the applet should be, go to the browser menu bar, choose to view the Java Console.
- In Netscape, you go to Communicator->Java console.
- In Intenet Explorer you need to got to View->Internet Options->Advanced and then click the box that says "Java Console enabled". Then go to View->Java console
- The Java Console will have all the errors that happened.
- Copy the error message EXACTLY and send that in an email to the author or a support network like the JavaBoutique Discussion Group.
If you do not send the error mesage EXACTLY it is very hard for someone else to figure out what the problem is.
Error messages often hold crucial clues.
Selena Sol contributes to the JavaBoutique's Introduction to Java. Selena curently works for Barclays Capital in London, one of the leading global investment banks in Europe and has worked as a software developer for the National Center for Human Genome research, Microline Software, Neuron Data, and Electric Eye in Singapore. Selena is perhaps best-known for creating the Public Domain Web Script Archive (Extropia) and writing several books on Web Programming (Perl, CGI, Java).
Email: selena@extropia.com
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