py.una.pol.karaku.replication.client.ReplicationResponseHandler.java Source code

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Here is the source code for py.una.pol.karaku.replication.client.ReplicationResponseHandler.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.replication.client;

import static py.una.pol.karaku.util.Checker.notNull;
import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import org.apache.commons.lang3.tuple.ImmutablePair;
import org.apache.commons.lang3.tuple.Pair;
import org.springframework.stereotype.Component;
import org.springframework.util.ReflectionUtils;
import py.una.pol.karaku.util.KarakuReflectionUtils;

/**
 * 
 * @author Arturo Volpe
 * @since 2.2.8
 * @version 1.0 Nov 26, 2013
 * 
 */
@Component
public class ReplicationResponseHandler {

    private static final String[] ID_FIELDS = { "id", "lastId" };
    private static final String[] CHANGE_FIELDS = { "entities", "data" };

    /**
     * Retorna un par inmutable que consta del ultimo identificador como llave,
     * y la lista de cambios como valor.
     * 
     * @param t1
     *            objeto retornado
     * @return pair, nunca <code>null</code>, que consta de la llave la ultima
     *         clave, y el valor la lista de cambios (no nula);
     */
    public Pair<String, Collection<?>> getChanges(Object t1) {

        return new ImmutablePair<String, Collection<?>>(getLastId(t1), getItems(t1));
    }

    /**
     * @param response
     * @return
     */
    @SuppressWarnings("rawtypes")
    private Collection getItems(Object response) {

        Object respuesta = notNull(response, "Cant get changes from null response");
        Class<?> clazz = notNull(respuesta.getClass());
        Field f = KarakuReflectionUtils.findField(clazz, CHANGE_FIELDS);

        if (f == null) {
            f = ReflectionUtils.findField(response.getClass(), null, List.class);
        }

        notNull(f,
                "Cant get the id field, " + "use the @ReplicationData annotation or create "
                        + "a field with name %s, please see %s",
                Arrays.toString(CHANGE_FIELDS), response.getClass().getName());
        f.setAccessible(true);
        Collection c = (Collection) ReflectionUtils.getField(f, response);

        if (c == null) {
            return Collections.EMPTY_LIST;
        }
        return c;
    }

    /**
     * @param response
     * @return
     */
    private String getLastId(Object response) {

        notNull(response, "Cant get id from null response");
        Class<?> clazz = notNull(response.getClass());

        Field f = KarakuReflectionUtils.findField(clazz, ID_FIELDS);

        notNull(f,
                "Cant get the id field, please use the @ReplicationId "
                        + "annotation, or create a field with name %s, see %s",
                Arrays.toString(ID_FIELDS), response.getClass());

        f.setAccessible(true);

        Object id = ReflectionUtils.getField(f, response);
        notNull(id, "Id null in response is not allowed");

        return id.toString();
    }
}