Opetushallitus/eperusteet-opintopolku

package fi.vm.sade.eperusteet.opintopolku;

/*
 * Copyright (c) 2013 The Finnish Board of Education - Opetushallitus
 *
 * This program is free software: Licensed under the EUPL, Version 1.1 or - as soon as they will be approved by the European Commission - subsequent versions of
 * the EUPL (the "Licence");
 *
 * You may not use this work except in compliance with the Licence. You may obtain a copy of the Licence at: http://ec.europa.eu/idabc/eupl
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the European Union Public Licence for more details.
 */
import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author jhyoty
 */
@WebServlet(urlPatterns = {"/config.json"}, loadOnStartup = 1)
public class ConfigServlet extends HttpServlet {

    private Map<String, String> config;
    private final ObjectMapper mapper = new ObjectMapper();

    @Override
    public void init() throws ServletException {
        final String home = System.getProperty("user.home");
        final Path path = FileSystems.getDefault().getPath(home,"oph-configuration","eperusteet-opintopolku.properties");
        try (Reader props = Files.newBufferedReader(path, StandardCharsets.ISO_8859_1)) {
            Properties p = new Properties();
            p.load(props);
            HashMap<String, String> tmp = new HashMap<>();
            for (Map.Entry<Object, Object> e : p.entrySet()) {
                tmp.put(e.getKey().toString(), e.getValue().toString());
            }
            this.config = Collections.unmodifiableMap(tmp);

        } catch (IOException ex) {
            throw new ServletException(ex);
        }
    }

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        response.setContentType("application/json;charset=UTF-8");
        response.setCharacterEncoding("UTF-8");
        try (PrintWriter out = response.getWriter()) {
            mapper.writeValue(out, config);
        }
    }

    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        processRequest(request, response);
    }

}