/*

 * Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiary(-ies).

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of the License "Eclipse Public License v1.0"

 * which accompanies this distribution, and is available

 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

 *

 * Initial Contributors:

 * Nokia Corporation - initial contribution.

 *

 * Contributors:

 *

 * Description:  

 *

 */

package com.nokia.helium.metadata;

import java.io.Serializable;

import java.util.List;

/**

 * Interface to implement the Data Access Object pattern. 

 *

 * @param <T> the type of the object to persist.

 */

public interface DAO<T> {

    /**

     * Find a particular T object based on it's id. 

     * @param id the id to look for.

     * @return the retrieved object, or null if not found.

     */

    T findById(Serializable id);

    /**

     * Finding all rows from the database.

     * @return the list of T objects.

     */

    List<T> findAll();

    /**

     * Persisting the data object from the database. 

     * @param data the object to persist

     */

    void persist(T data);

    /**

     * Removing the data object from the database.

     * @param data the row to be removed

     */

    void remove(T data);

}