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1   /*
2    * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package com.sun.rowset.internal;
27  
28  import java.sql.*;
29  import java.io.*;
30  import java.util.Arrays;
31  
32  /**
33   * The abstract base class from which the classes <code>Row</code>
34   * The class <code>BaseRow</code> stores
35   * a row's original values as an array of <code>Object</code>
36   * values, which can be retrieved with the method <code>getOrigRow</code>.
37   * This class also provides methods for getting and setting individual
38   * values in the row.
39   * <P>
40   * A row's original values are the values it contained before it was last
41   * modified.  For example, when the <code>CachedRowSet</code>method
42   * <code>acceptChanges</code> is called, it will reset a row's original
43   * values to be the row's current values.  Then, when the row is modified,
44   * the values that were previously the current values will become the row's
45   * original values (the values the row had immediately before it was modified).
46   * If a row has not been modified, its original values are its initial values.
47   * <P>
48   * Subclasses of this class contain more specific details, such as
49   * the conditions under which an exception is thrown or the bounds for
50   * index parameters.
51   */
52  public abstract class BaseRow implements Serializable, Cloneable {
53  
54  /**
55   * Specify the serialVersionUID
56   */
57  private static final long serialVersionUID = 4152013523511412238L;
58  
59  /**
60   * The array containing the original values for this <code>BaseRow</code>
61   * object.
62   * @serial
63   */
64      protected Object[] origVals;
65  
66  /**
67   * Retrieves the values that this row contained immediately
68   * prior to its last modification.
69   *
70   * @return an array of <code>Object</code> values containing this row's
71   * original values
72   */
73      public Object[] getOrigRow() {
74          Object[] origRow = this.origVals;
75          return (origRow == null) ? null: Arrays.copyOf(origRow, origRow.length);
76      }
77  
78  /**
79   * Retrieves the array element at the given index, which is
80   * the original value of column number <i>idx</i> in this row.
81   *
82   * @param idx the index of the element to return
83   * @return the <code>Object</code> value at the given index into this
84   *         row's array of original values
85   * @throws SQLException if there is an error
86   */
87      public abstract Object getColumnObject(int idx) throws SQLException;
88  
89  /**
90   * Sets the element at the given index into this row's array of
91   * original values to the given value.  Implementations of the classes
92   * <code>Row</code> and determine what happens
93   * when the cursor is on the insert row and when it is on any other row.
94   *
95   * @param idx the index of the element to be set
96   * @param obj the <code>Object</code> to which the element at index
97   *              <code>idx</code> to be set
98   * @throws SQLException if there is an error
99   */
100     public abstract void setColumnObject(int idx, Object obj) throws SQLException;
101 }