With Java ScriptEngine (Groovy), how to make it more performant?

Question

I am using ScriptEngine in my app to evaluate some client code in my application. The problem is it\'s not performant enough and I need to take measures to improve the time

Answer 1

Most likely the problem is that the engine actually evaluates the script every time eval() is called. Instead, you could re-use the precompiled script via Compilable interface.

    // move this into initialization part so that you do not call this every time.
    ScriptEngineManager manager = new ScriptEngineManager();
    ScriptEngine engine  = manager.getEngineByName("groovy");
    CompiledScript script = ((Compilable) engine).compile(urlGeneratorScript);

    //the code below will use the precompiled script code
    Bindings bindings = new Bindings();
    bindings.put("state", state;
    bindings.put("zipcode", zip);
    bindings.put("url", locationAwareAd.getLocationData().getGeneratedUrl());
    url = script.eval(bindings);

FWIW, you can also implement the file timestamp check, if the script is changed call compile(..) again.