py.una.pol.karaku.dao.entity.watchers.WatcherHandler.java Source code

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Here is the source code for py.una.pol.karaku.dao.entity.watchers.WatcherHandler.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.dao.entity.watchers;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.annotation.Nonnull;
import javax.annotation.PostConstruct;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import py.una.pol.karaku.dao.entity.Operation;

/**
 * 
 * @author Arturo Volpe
 * @since 2.2.8
 * @version 1.0 Nov 6, 2013
 * 
 */
@Component
public class WatcherHandler {

    @Autowired(required = false)
    private List<Watcher<?>> watchers;

    private Map<Class<?>, List<Watcher<?>>> maps;

    @PostConstruct
    void init() {

        maps = new HashMap<Class<?>, List<Watcher<?>>>();

        if (watchers == null) {
            return;
        }
        for (Watcher<?> w : watchers) {
            addOrCreateAndAdd(w, w.getTargetClass());
        }
    }

    private void addOrCreateAndAdd(Watcher<?> w, Class<?> c) {

        if (maps.get(c) == null) {
            maps.put(c, new ArrayList<Watcher<?>>());
        }
        maps.get(c).add(w);
    }

    /**
     * @return
     */
    public List<Watcher<?>> getWatchers() {

        return watchers;
    }

    /**
     * @param operation
     * @param dc
     * @return
     */
    @SuppressWarnings("unchecked")
    @Nonnull
    public <T> Operation redirect(@Nonnull Operation operation, @Nonnull Class<T> clazz, @Nonnull T dc) {

        Set<Watcher<?>> clazzwatchers = getWatchers(clazz);

        for (Watcher<?> watcher : clazzwatchers) {
            Watcher<T> wath = (Watcher<T>) watcher;
            Operation nOp = wath.redirect(operation, dc);
            if (!nOp.equals(operation)) {
                return redirect(nOp, clazz, dc);
            }
        }
        return operation;
    }

    /**
     * @param operation
     * @param dc
     * @return
     */
    @SuppressWarnings("unchecked")
    public <T> T process(Operation origin, Operation operation, Class<T> clazz, T dc) {

        Set<Watcher<?>> currentWatchers = getWatchers(clazz);

        T bean = dc;
        for (Watcher<?> watcher : currentWatchers) {
            Watcher<T> wath = (Watcher<T>) watcher;
            bean = wath.process(origin, operation, bean);
        }
        return bean;
    }

    /**
     * @param clazz
     * @return
     */
    private <T> Set<Watcher<?>> getWatchers(Class<T> clazz) {

        Set<Watcher<?>> currentWatchers = new HashSet<Watcher<?>>();
        for (Entry<Class<?>, List<Watcher<?>>> entry : maps.entrySet()) {

            Class<?> oClazz = entry.getKey();
            if (oClazz.isAssignableFrom(clazz)) {
                currentWatchers.addAll(entry.getValue());
            }
        }
        return currentWatchers;
    }
}