AbstractDao.java

package org.jtheque.persistence.utils;

/*
 * Copyright JTheque (Baptiste Wicht)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import org.jtheque.persistence.Dao;
import org.jtheque.persistence.DaoPersistenceContext;
import org.jtheque.persistence.DataListener;
import org.jtheque.persistence.QueryMapper;
import org.jtheque.persistence.Entity;
import org.jtheque.utils.annotations.GuardedInternally;
import org.jtheque.utils.annotations.ThreadSafe;
import org.jtheque.utils.collections.WeakEventListenerList;

import org.springframework.jdbc.core.RowMapper;

import javax.annotation.Resource;

/**
 * An abstract Dao using Spring JDBC.
 *
 * @author Baptiste Wicht
 * @param <T> The type of data contained in this DAO.
 */
@ThreadSafe
public abstract class AbstractDao<T extends Entity> implements Dao<T> {
    @Resource
    private DaoPersistenceContext persistenceContext;

    @GuardedInternally
    private final WeakEventListenerList<DataListener> listenerList = WeakEventListenerList.create();

    private final String table;

    /**
     * Construct a new AbstractDao.
     *
     * @param table The table of this dao.
     */
    protected AbstractDao(String table) {
        super();

        this.table = table;
    }

    @Override
    public final void addDataListener(DataListener listener) {
        listenerList.add(listener);
    }

    @Override
    public final void removeDataListener(DataListener listener) {
        listenerList.remove(listener);
    }

    @Override
    public String getTable() {
        return table;
    }

    /**
     * Return the query mapper for the DAO.
     *
     * @return The query mapper for the DAO.
     */
    protected abstract QueryMapper getQueryMapper();

    /**
     * Return the row mapper of this DAO.
     *
     * @return The RowMapper of this DAO.
     */
    protected abstract RowMapper<T> getRowMapper();

    /**
     * Return the persistence context for this dao.
     *
     * @return The persistence context for this dao.
     */
    protected DaoPersistenceContext getContext() {
        return persistenceContext;
    }

    /**
     * Avert the listeners that the data have changed.
     */
    protected final void fireDataChanged() {
        for (DataListener listener : listenerList) {
            listener.dataChanged();
        }
    }
}