dynamically executing java code

[pouncer]

if a user submits their .java file to my online website, how could i make my java application automatically execute this code?

my java application runs on an aplet, and the things users submit are computer players for a game competition

[dlorde]

If they are submitting .java files (source code), you need to compile it before you can run it.

Check out the Compiler API - see JSR 199: Programmatic Compiling and Programmatic Compilation.

Once you've got the code compiled, you should be able load the class files with a class loader and run it in your own application.

Sounds easy, doesn't it? I bet it isn't...

The cheapest, fastest, and most reliable components of a computer system are those that aren't there...
G. Bell

[keang]

This classloaders tutorial shows an example of using classloaders by writing a sample program that compiles and runs code on the fly. This may just provide the basis of what you want.