1 /*

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

     3  * All rights reserved.

     4  * This component and the accompanying materials are made available

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

     6  * which accompanies this distribution, and is available

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

     8  *

     9  * Initial Contributors:

    10  * Nokia Corporation - initial contribution.

    11  *

    12  * Contributors:

    13  *

    14  * Description:  

    15  *

    16  */

    17 package com.nokia.helium.metadata;

    18 

    19 import java.io.Serializable;

    20 import java.util.List;

    21 

    22 /**

    23  * Interface to implement the Data Access Object pattern. 

    24  *

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

    26  */

    27 public interface DAO<T> {

    28     

    29     /**

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

    31      * @param id the id to look for.

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

    33      */

    34     T findById(Serializable id);

    35     

    36     /**

    37      * Finding all rows from the database.

    38      * @return the list of T objects.

    39      */

    40     List<T> findAll();

    41     

    42     /**

    43      * Persisting the data object from the database. 

    44      * @param data the object to persist

    45      */

    46     void persist(T data);

    47 

    48     /**

    49      * Removing the data object from the database.

    50      * @param data the row to be removed

    51      */

    52     void remove(T data);

    53 }