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1   /*
2    * Copyright (c) 2005, 2006, 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
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24   */
25  
26  package java.sql;
27  
28  /**
29   *
30   * The representation (mapping) in the Java programming language of an SQL ROWID
31   * value. An SQL ROWID is a built-in type, a value of which can be thought of as
32   * an address  for its identified row in a database table. Whether that address
33   * is logical or, in any  respects, physical is determined by its originating data
34   * source.
35   * <p>
36   * Methods in the interfaces <code>ResultSet</code>, <code>CallableStatement</code>,
37   * and <code>PreparedStatement</code>, such as <code>getRowId</code> and <code>setRowId</code>
38   * allow a programmer to access a SQL <code>ROWID</code>  value. The <code>RowId</code>
39   * interface provides a method
40   * for representing the value of the <code>ROWID</code> as a byte array or as a
41   * <code>String</code>.
42   * <p>
43   * The method <code>getRowIdLifetime</code> in the interface <code>DatabaseMetaData</code>,
44   * can be used
45   * to determine if a <code>RowId</code> object remains valid for the duration of the transaction in
46   * which  the <code>RowId</code> was created, the duration of the session in which
47   * the <code>RowId</code> was created,
48   * or, effectively, for as long as its identified row is not deleted. In addition
49   * to specifying the duration of its valid lifetime outside its originating data
50   * source, <code>getRowIdLifetime</code> specifies the duration of a <code>ROWID</code>
51   * value's valid lifetime
52   * within its originating data source. In this, it differs from a large object,
53   * because there is no limit on the valid lifetime of a large  object within its
54   * originating data source.
55   * <p>
56   * All methods on the <code>RowId</code> interface must be fully implemented if the
57   * JDBC driver supports the data type.
58   *
59   * @see java.sql.DatabaseMetaData
60   * @since 1.6
61   */
62  
63  public interface RowId {
64      /**
65       * Compares this <code>RowId</code> to the specified object. The result is
66       * <code>true</code> if and only if the argument is not null and is a RowId
67       * object that represents the same ROWID as  this object.
68       * <p>
69       * It is important
70       * to consider both the origin and the valid lifetime of a <code>RowId</code>
71       * when comparing it to another <code>RowId</code>. If both are valid, and
72       * both are from the same table on the same data source, then if they are equal
73       * they identify
74       * the same row; if one or more is no longer guaranteed to be valid, or if
75       * they originate from different data sources, or different tables on the
76       * same data source, they  may be equal but still
77       * not identify the same row.
78       *
79       * @param obj the <code>Object</code> to compare this <code>RowId</code> object
80       *     against.
81       * @return true if the <code>RowId</code>s are equal; false otherwise
82       * @since 1.6
83       */
84      boolean equals(Object obj);
85  
86      /**
87       * Returns an array of bytes representing the value of the SQL <code>ROWID</code>
88       * designated by this <code>java.sql.RowId</code> object.
89       *
90       * @return an array of bytes, whose length is determined by the driver supplying
91       *     the connection, representing the value of the ROWID designated by this
92       *     java.sql.RowId object.
93       */
94       byte[] getBytes();
95  
96       /**
97        * Returns a String representing the value of the SQL ROWID designated by this
98        * <code>java.sql.RowId</code> object.
99        * <p>
100       *Like <code>java.sql.Date.toString()</code>
101       * returns the contents of its DATE as the <code>String</code> "2004-03-17"
102       * rather than as  DATE literal in SQL (which would have been the <code>String</code>
103       * DATE "2004-03-17"), toString()
104       * returns the contents of its ROWID in a form specific to the driver supplying
105       * the connection, and possibly not as a <code>ROWID</code> literal.
106       *
107       * @return a String whose format is determined by the driver supplying the
108       *     connection, representing the value of the <code>ROWID</code> designated
109       *     by this <code>java.sql.RowId</code>  object.
110       */
111      String toString();
112 
113      /**
114       * Returns a hash code value of this <code>RowId</code> object.
115       *
116       * @return a hash code for the <code>RowId</code>
117       */
118      int hashCode();
119 
120 }