IndexServlet.java

package org.aplikator.server;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.HashMap;
import java.util.Map;

import freemarker.core.Environment;
import freemarker.template.Configuration;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import freemarker.template.TemplateExceptionHandler;

/**
 *
 */
@WebServlet(
        name = "IndexServlet",
        urlPatterns = {"/index.html"})
public class IndexServlet extends HttpServlet {

    private static final String CHAR_ENCODING = "UTF-8";

    private static Configuration getFreemarkerConfig() {
        return LazyHolder.instance;
    }

    private static Configuration instance() {
        Configuration cfg = new Configuration(Configuration.VERSION_2_3_23);
        cfg.setClassForTemplateLoading(IndexServlet.class, "");
        cfg.setDefaultEncoding(CHAR_ENCODING);
        cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
        cfg.setLogTemplateExceptions(false);
        return cfg;
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Map<String, String> root = new HashMap<String, String>();
        root.put("context", req.getContextPath().replace("/", ""));
        root.put("title", Configurator.get().getLocalizedString("aplikator.brand", req.getLocale()));


        /* Get the template (uses cache internally) */
        Template temp = getFreemarkerConfig().getTemplate("index.ftlh");

        /* Merge data-model with template */
        Writer out = new OutputStreamWriter(resp.getOutputStream(), CHAR_ENCODING);
        try {
            //temp.process(root, out);
            Environment env = temp.createProcessingEnvironment(root, out);
            env.setOutputEncoding(CHAR_ENCODING);
            env.process();
        } catch (TemplateException e) {
            throw new ServletException(e);
        }
    }

    private static class LazyHolder {
        private static Configuration instance = instance();
    }
}