如何从servlet调用JavaScript的功能

import javax.script.ScriptEngineManager;
import javax.script.ScriptException;

import org.apache.catalina.Context;
import org.apache.catalina.servlets.Servlet;

public class MyServlet extends Servlet {
  @Override
  public void init() throws ServletException {
    super.init();
    ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
    ScriptEngine scriptEngine = scriptEngineManager.getEngineByName("javascript");
    scriptEngine.eval("function helloWorld() { console.log('Hello, World!'); }");
  }

  @Override
  public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    Context context = getServletContext();
    scriptEngine.eval(context.getInitParameter("myScript"));
  }
}