gistfile1.java

public class Application {

  public static void main(String[] args) throws IOException {
    final Configuration cfg = configureFreemarker();

    get(new Route("/") {
      @Override
      public Object handle(Request request, Response response) {

        //freemarker needs a Writer to render the final Html code
        StringWriter sw = new StringWriter();

        //params used in the template files
        //passed the sublayout filename and the title page
        HashMap<String, String> params = getPageParams("home.ftl", "Home page");
        try {

          //template engine processing
          cfg.getTemplate("main.ftl").process(params, sw);
        } catch (Exception e) {
          e.printStackTrace();
        }

        //return the rendered html code
        return sw.toString();
      }
    });
  }

  private static Configuration configureFreemarker() {
    Configuration cfg = new Configuration();

    try {

      //indicates the templates directory to freemarker
      cfg.setDirectoryForTemplateLoading(new File("templates"));
    } catch (IOException e) {
      e.printStackTrace();
    }
    return cfg;
  }
  
  //uses to create a Hashmap with specific keys
  private static HashMap<String, String> getPageParams(String page, String title) {
    HashMap<String, String> params = new HashMap<String, String>();

    //page and title from main.ftl
    params.put("page", "pages/" + page);
    params.put("title", title);
    return params;
  }

}