I've got this crazy feeling that everyone's going to come and see me about how to get the SimpleIR example to compile and work, so I'm posting this little help document in the hopes that there won't be quite as many people knocking on my door or calling my cell phone about this.

For one, make sure you have the latest version --- the first one I posted did indeed have some problems; I fixed them and reposted the thing. You can download it here as well.

After you've tar-gunzipped the thing into a directory (preserve the paths), you should have the following directory structure:
    SimpleIR (contains a sample config file)
        /ir (contains bytecode)
        /src
            /ir (contains source)

I've already compiled the thing for you, and the compiled .class files can be found in the ir subdirectory, but if you want to recompile it (why?), execute the following command in the SimpleIR directory:
    javac -d . src/ir/*

Assuming you have javac installed correctly, this will compile all the source files and place the compiled .class files in the ir subdirectory. You can now proceed to try and run the thing. You do so by executing in the SimpleIR directory the following:
    java ir.SimpleIRUserInterface <conf_file_name>

Oh, and you do need to type in a valid configuration file name, a sample of which is provided as SimpleIR.cfg, and you do need to make modifications to the conf file so that it has proper values for all the listed items which the engine cares about. Fun, fun.

If you want to take a look at another sample information retrieval engine, or need help with JavaCC or other miscellaneous Java problems, you might take a look at my old Java class web page.