ClassNotFoundException after Java version update

Question

I have an old Java web application that still uses Applets (not my decision).

After a recent Java upgrade (I believe it was 1.7 to 1.8) the app now throws a ClassNotFoundException and says that it can't find the JApplet class the Applet derives from before the Applet can load.

The path to the class is specified in a jsp page called loadApplet.jsp.

Here is the code in the loadApplet.jsp file. The only part that isn't an exact copy and paste is ThePathToTheJAppletClassWhichItAlwaysFoundBefore.class - which is just a string that defines where the package is.

<OBJECT classid = "clsid:8AD9C840-044E-11D1-B3E9-00805F499D93" codebase = "https://java.sun.com/products/plugin/autodl/jinstall-1_4-windows-i586.cab#Version=1,4,0,0" height = "0" width = "0">
<PARAM NAME = "CODE"          VALUE = "ThePathToTheJAppletClassWhichItAlwaysFoundBefore.class" >
<PARAM NAME = "type"          VALUE = "application/x-java-applet;jpi-version=1.3.1" >
<PARAM NAME = "scriptable"    VALUE = "false" >

Answer 1

Thanks for all the suggestions. What happened was during the upgrade the Java Security settings were automatically set to Very High - thus the class on the client could not be found. I reset the setting to High and it worked fine.