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Applet Requirements
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The internal workings of the Jython interpreter rely on certain
operations that are not permitted for Java applets by default.
Therefore, you will have to change your Java policy file
to grant the following permissions to the applet, or the applet
will not run.
You will have to reload this page after changing your policy file.
Please check your browser and JDK/JRE/Java plugin
documentation for the details about the policy file location and syntax.
For example, on Unix/Linux systems, the policy file is called
.java.policy and located in your home directory.
First, the applet needs a PropertyPermission because the Jython
interpreter initialization reads your system properties.
This is fairly low risk, but exposes your user name and home
directory location to the applet.
Second, Jython requires a few RuntimePermissions because
it relies on its own classloader - the Jython input is first
compiled to Java bytecodes which are then loaded into the Java
virtual machine and executed by the Java VM.
Allowing classloader access is dangerous in general,
but absolutely necessary in this case.
Finally, if you would like to use your own Python input scripts with the
applet, you will have to grant local file access to the applet.
Note that you should never grant extra permissions to applets
from unknown or untrustworthy sites - you will have to decide for
yourself whether running Jython is worth the extra risk.
The following
template policy file
shows the (minimum) permissions required to
run the Jython interpreter applet. The codeBase entries grant the
permissions only to applets from this server:
/* AUTOMATICALLY GENERATED ON Thu Oct 04 11:12:41 CEST 2001*/
/* DO NOT EDIT */
grant codeBase "http://tams-www.informatik.uni-hamburg.de/applets/-" {
permission java.util.PropertyPermission "*", "read,write";
};
grant codeBase "http://tams-www.informatik.uni-hamburg.de/applets/jython/-" {
permission java.lang.RuntimePermission "createClassLoader";
permission java.lang.RuntimePermission "getClassLoader";
permission java.lang.RuntimePermission "getProtectionDomain";
};
grant codeBase "http://tams-www.informatik.uni-hamburg.de/applets/-" {
permission java.io.FilePermission "<>", "read, write, delete, execute";
};
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