Java applet problems

The HALcell Java applet

If there are problems getting the Java applets here to run, hopefully the information here will be of some help.

The applets here require Java 1.1 to operate successfully. They use the new event model which is not available in environments which support Java 1.0.2.

The class files are stored in a 'jar' (Java ARchive). Jars now seem to be pretty widely supported.

The class files have been squeezed by IBM's JAX program in the hope of producing faster download times and improved runtime performance.

I've tested the applets in IE 5.0 Netscape 4.5 and with "appletviewer"s from Sun's JDK 1.2.1 and IBM's JDK 1.1.7 runtime environments. They appear to run without any particularly serious problems.

Pages providing native applets and applets designed to run using Sun's browser plug-in are probided. Various bugs in each of these Java runtime implementations adversely affect the performance of my applets in various ways - but they should at least run.

My applets are currently quite poor at trapping exceptions caused by failure to allocate memory. As my machine has 128Mb, I don't notice these much myself. If the applets crash when you try to run them using high resolutions, "refresh" them and try less ambitions resolutions. I hope to be able to sort this problem out at some stage.

There appear be problems when running the applets here under some unix variants. On my Linux installation, Netscape completely crashes when it tries to run my applets. The applets work fine in Sun's appletviewer, or using the Java plug-in in these environments, though.

This is obviously Netscape's bug. My investigations apear to reveal that the problem is located in the thread handling code, which appears to be so broken that working around the problem would be highly impractical.

Hopefully future unix Netscape variants will have Java virtual machines which don't exhibit this type of severe problem.

If you have problem running the applets which is not mentioned above, you can try contacting me to see if I can sort things out.

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