# Results.java

    /*
    ** Module   : Results.java
    ** Abstract : Abstraction layer interface for query results
    **
    ** Copyright (c) 2006-2024, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- --JPRM-- ---------------------------Description------------------------------
    ** 001 ECF 20060214   @24711 Created initial version. Defines an API which abstracts the results
    **                           of a joinable query.
    ** 002 ECF 20060725   @28190 Added cleanup() method.
    ** 003 ECF 20070711   @34444 Added sessionClosing() method. This is needed in addition to
    **                           cleanup() because it may be necessary to behave differently at
    **                           session closing than at the end of the Results object's life.
    ** 004 ECF 20190427          Fixed results caching.
    ** 005 SVL 20191002          Added addRow.
    ** 006 ECF 20200906          New ORM implementation.
    ** 007 AL2 20230315          Added isAutoFetch.
    ** 008 AD  20231110          Added get() method with forceOnlyId parameter, with default implementation.
    **     AD  20231113          Added warning log in default implementation of get(boolean).
    **     AD  20231116          Made logger from default get() a static field.
    **     AD  20231124          Added condition when logging use of default implementation of get(boolean).
    ** 009 AL2 20240906          Made get call get(forceIdOnly) with false argument by default.
    */

    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program 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 Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
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    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
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    **     attribution required in this license.
    */

    package com.goldencode.p2j.persist;

    import com.goldencode.p2j.util.logging.CentralLogger;

    /**
     * An abstraction layer between a joinable query implementation and its results.  This interface
     * defines methods for manipulating a results set using a scrollable cursor paradigm.  Each row
     * is a virtual composite of one or more records, each represented by its primary key ID or by a
     * reference to the DMO itself.
     */
    interface Results
    {
       /** Logger */
       static final CentralLogger LOG = CentralLogger.get(Results.class.getName());

       /**
        * Move cursor to the first results row.
        *
        * @return  {@code true} if there are any results.
        */
       public boolean first();

       /**
        * Move cursor to the last results row.
        *
        * @return  {@code true} if there are any results.
        */
       public boolean last();

       /**
        * Move cursor to the next results row.
        *
        * @return  {@code true} if there is a result under the cursor after the move.
        */
       public boolean next();

       /**
        * Move cursor to the previous results row.
        *
        * @return  {@code true} if there is a result under the cursor after the move.
        */
       public boolean previous();

       /**
        * Is the cursor on the first row in the results set?
        *
        * @return  {@code true} if the cursor is on the first row.
        */
       public boolean isFirst();

       /**
        * Is the cursor on the last row in the results set?
        *
        * @return  {@code true} if the cursor is on the first row.
        */
       public boolean isLast();

       /**
        * Is the result delegate responsible for fetching? This is usually true when using
        * query delegates which handle the fetching process already.
        *
        * @return   {@code true} for complex results which also do the fetching.
        */
       default public boolean isAutoFetch()
       {
          return false;
       }

       /**
        * Get the array of objects at the current result row.
        *
        * @return  Object array or {@code null}.
        */
       default public Object[] get()
       {
          return get(false);
       }

       /**
        * Returns the row at the current position. It can be either only an array of PK or
        * an array of DMOs.
        *
        * @param   forceOnlyId
        *          Indicates whether it's only the primary keys that must be returned,
        *          or original data found is returned (either PK or DMO).
        *
        * @return  Object array or {@code null}.
        */
       public Object[] get(boolean forceOnlyId);

       /**
        * Get the object at the current result row, at the specified column.
        *
        * @param   column
        *          Zero-based index column of the desired object.
        *
        * @return  Object at {@code column} or {@code null}.
        */
       public Object get(int column);

       /**
        * Get the primary key ID at the current result row, at the specified column.
        *
        * @param   column
        *          Zero-based index column of the desired ID.
        *
        * @return  ID of the record or {@code null}.
        */
       public Long getID(int column);

       /**
        * Get the row number currently under the cursor.
        *
        * @return  Zero-based index of the current row, or {@code -1} if the cursor is not currently
        * on a result.
        */
       public int getRowNumber();

       /**
        * Set the row number currently under the cursor.
        *
        * @param   row
        *          Zero-based index of the row to be set as the current row.
        *
        * @return  {@code true} if there is a row at the specified row number, else {@code false}.
        */
       public boolean setRowNumber(int row);

       /**
        * Scroll the cursor ahead by the specified number of rows.  If the number is negative, the
        * cursor is moved backward. This may put the cursor off the end (either end) of the query's
        * results.
        *
        * @param   rows
        *          Number of rows to jump ahead or back.
        *
        * @return  {@code true} if there is a row at the new location, else {@code false}.
        */
       public boolean scroll(int rows);

       /**
        * Reset the cursor to its natural starting position, before the first result row.
        */
       public void reset();

       /**
        * Invoked when the current Hibernate session is about to close. Gives the implementation an
        * opportunity to perform appropriate processing in response to this event.
        */
       public void sessionClosing();

       /**
        * Clean up and release any resources which this object is holding, such as open result sets.
        */
       public void cleanup();

       /**
        * Indicate whether the full result set is cached in this object.
        *
        * @return  {@code true} if all results are contained this object; {@code false} if not or
        *          if unknown (such as for a scrolling or cursored result set. Default return value
        *          is {@code false}.
        */
       public default boolean isResultSetCached()
       {
          return false;
       }

       /**
        * Returns the number of rows which have been loaded by this object.
        *
        * @return  This default implementation returns 0.
        */
       public default int getNumberOfLoadedRows()
       {
          return 0;
       }

       /**
        * Delete the current row. This is an optional operation and this default implementation does
        * nothing.
        *
        * @return  {@code true} if the row was deleted. {@code false} if there is no row at
        *          the current position. This default implementation returns {@code false}.
        */
       public default boolean deleteRow()
       {
          return false;
       }

       /**
        * Add a new row.
        *
        * @param row
        *        Row data.
        * @param beforeRow
        *        <code>true</code> if the current position is before the row. <code>false</code> if
        *        the current position is on the row.
        */
       public default void addRow(Object[] row, boolean beforeRow)
       {
          throw new IllegalStateException("Cannot add a row for this type of results");
       }
    }