py.una.pol.karaku.menu.server.MenuServerLogic.java Source code

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Here is the source code for py.una.pol.karaku.menu.server.MenuServerLogic.java

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/*-
 * Copyright (c)
 *
 *       2012-2014, Facultad Politcnica, Universidad Nacional de Asuncin.
 *       2012-2014, Facultad de Ciencias Mdicas, Universidad Nacional de Asuncin.
 *       2012-2013, Centro Nacional de Computacin, Universidad Nacional de Asuncin.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301  USA
 */
package py.una.pol.karaku.menu.server;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.NavigableSet;
import java.util.TreeSet;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import org.apache.commons.lang3.CharEncoding;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Component;
import py.una.pol.karaku.configuration.PropertiesUtil;
import py.una.pol.karaku.exception.KarakuRuntimeException;
import py.una.pol.karaku.menu.schemas.Menu;
import py.una.pol.karaku.util.I18nHelper;
import py.una.pol.karaku.util.ListHelper;
import py.una.pol.karaku.util.StringUtils;

/**
 * Component que provee las funcionalidades para proveer mens.
 * 
 * <p>
 * Funciones de esta clase:
 * <ol>
 * <li>Obtener el men del sistema actual, ver {@link #getCurrentSystemMenu()}</li>
 * <li>Construir un men dado, ver {@link #configMenu(Menu)}</li>
 * 
 * </ol>
 * </p>
 * 
 * @author Arturo Volpe
 * @since 2.2.8
 * @version 1.0 Oct 17, 2013
 * 
 */
@Component
public class MenuServerLogic {

    /**
     * Ubicacin de dondes se busca el menu del sistema.
     */
    public static final String KARAKU_MENU_LOCATION_KEY = "karaku.menu.location";

    @Autowired
    private I18nHelper helper;

    @Autowired
    private PropertiesUtil util;

    /**
     * Recibe un men y lo construye.
     * 
     * <p>
     * Se dice que un men configurado es aquel que ya esta ordenado, todas sus
     * cadenas estn internacionalizadas y su URL es absoluta.
     * </p>
     * 
     * @param m
     *            men a configurar
     * @return men ya configurado (misma instancia que el pasado como
     *         parmetro)
     */
    public Menu configMenu(Menu m) {

        handleRootMenu(m);
        return m;
    }

    /**
     * Retorna el men del sistema.
     * 
     * @return Men del sistema actual
     */
    public List<Menu> getCurrentSystemMenu() {

        try {
            Resource resource = new ClassPathResource(util.get(KARAKU_MENU_LOCATION_KEY));
            BufferedReader reader = new BufferedReader(
                    new InputStreamReader(resource.getInputStream(), CharEncoding.ISO_8859_1));
            Unmarshaller um = JAXBContext.newInstance(Menu.class).createUnmarshaller();
            Menu m = (Menu) um.unmarshal(reader);
            configMenu(m);
            if (skip(m)) {
                return m.getItems();
            }
            return Arrays.asList(m);
        } catch (UnsupportedEncodingException e) {
            throw new KarakuRuntimeException("Cant open the menu (wrong encoding)", e);
        } catch (IOException e) {
            throw new KarakuRuntimeException("Cant open the menu (file not found)", e);
        } catch (JAXBException e) {
            throw new KarakuRuntimeException("Cant open the menu (wrong XML)", e);
        }
    }

    private void handleRootMenu(Menu menu) {

        // Este hashSet se usa como un queue, solamente que es deseable que no
        // tenga valores repetidos
        NavigableSet<Menu> toSort = new TreeSet<Menu>();
        Map<Menu, Menu> parents = new HashMap<Menu, Menu>();
        toSort.add(menu);
        Menu next;
        while (!toSort.isEmpty()) {

            next = toSort.pollFirst();
            handleMenu(next, parents.get(next));
            if (ListHelper.hasElements(next.getItems())) {
                sortInMemory(next.getItems());
                toSort.addAll(next.getItems());
                for (Menu m : next.getItems()) {
                    parents.put(m, next);
                }
            }
        }
    }

    private boolean skip(Menu menu) {

        return "true".equalsIgnoreCase(menu.getSkipThis());
    }

    private void sortInMemory(List<Menu> menus) {

        Collections.sort(menus);
    }

    /**
     * Este mtodo se ejecuta una sola vez por item en el men. El orden no esta
     * asegurado.
     */
    private void handleMenu(Menu menu, Menu parent) {

        if (skip(menu)) {
            return;
        }
        if (menu.getOrder() == 0) {
            menu.setOrder(Integer.MAX_VALUE);
        }
        if (StringUtils.isValid(menu.getName())) {
            menu.setName(helper.getString(menu.getName().trim()));
        }
        if (menu.getUrl() != null) {
            String pre = util.get("application.host", "");
            String url = menu.getUrl().trim();
            if (!pre.endsWith("/") && !url.startsWith("/")) {
                pre += "/";
            }
            menu.setUrl(pre + url);
        }

        if (parent != null) {
            menu.setId(parent.getId() + "_" + menu.getId());
        }
    }
}