DrJava scriptengine doesn't work - scriptengine

Question

I try to evaluate math expression in string form using scriptengine, but it throws me NullPointerException
java.lang.NullPointerException
at Math.main(Math.java:12)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:272)
Here is the code:
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Math{
public static void main(String[] args){
ScriptEngineManager mgr = new ScriptEngineManager();
ScriptEngine jsEngine = mgr.getEngineByName("JavaScript");
try {
System.out.println("scriptEngine result: "+jsEngine.eval("{2+4*3*[1+(1+2+4)]}"));
} catch (ScriptException ex) {
Logger.getLogger(Math.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
i tried the same code in netbeans and it works, but i also need it to work in DrJava development environment.
Is it possible to resolve this or is there any other library that can evaluate string like this with combination of all parenthesis "{[()]}"?