FileReader can't find R Script - r

Question

I try run my R Script within JavaFx. I use Renjin for this purpose and it seems to work properly with statements I run internally. But I want to run an external R Script. The project is set up with Maven so the path should be easy as the R Script is in the resources folder. The path works when I load FXML files, so I'm pretty confused why it can't find my Script.
Here's a short example:
package survey;
import javax.script.*;
import org.renjin.script.*;
import java.io.FileReader;
public class calcFunction {
public static void main(String[] args) throws Exception {
// create a script engine manager:
RenjinScriptEngineFactory factory = new RenjinScriptEngineFactory();
// create a Renjin engine:
ScriptEngine engine = factory.getScriptEngine();
engine.put("x", 4);
engine.put("y", 5);
engine.eval(new FileReader("/test.R"));
}
}
Is something missing? Thanks in advance!
EDIT1:
With my FXML files it works with the "/" path like this:
root = FXMLLoader.load(getClass().getResource("/moduleDa.fxml"));
EDIT2:
Someone who deleted his comment proposed this:
engine.eval(new FileReader(new File(".").getAbsolutePath()+"/test.R"));
It works if the script is in the root directory, where the pom.xml file is located. #James_D made it work so the R script can be located in the resources folder - thanks a lot!

Answer 1

If your R script is bundled as part of the application, it can't be treated as a file - you need to treat it as a resource. Typically, you will deploy your application as a Jar file, and the resources will be elements within that jar file (they won't be files in their own right).
So just treat the R script as a resource and load it as such. I don't know the renjin framework, but I assume ScriptEngine here is a javax.script.ScriptEngine, in which case ScriptEngine.eval(...) takes a Reader as a parameter, and so (if your R script is located in the root of the class path) you can do
engine.eval(new InputStreamReader(getClass().getResourceAsStream("/test.R")));