History

My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

Commit d37b88d1 parent 3f5b46618352 files · +2598093 −-8690Browse files

Showing the changes to java/pkg/javax/sql/rowset/FilteredRowSet.java (1 of 18352 files). Show all

Unified · Split

java/pkg/javax/sql/rowset/FilteredRowSet.java+160−0
@@ -0,0 +1,160 @@
1+/*
2+ * Copyright (c) 2003, 2004, 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 javax.sql.rowset;
27+
28+import java.sql.*;
29+import javax.sql.*;
30+import javax.naming.*;
31+import java.io.*;
32+import java.math.*;
33+
34+/**
35+ * The standard interface that all standard implementations of
36+ * <code>FilteredRowSet</code> must implement. The <code>FilteredRowSetImpl</code> class
37+ * provides the reference implementation which may be extended if required.
38+ * Alternatively, a vendor is free to implement its own version
39+ * by implementing this interface.
40+ *
41+ * <h3>1.0 Background</h3>
42+ *
43+ * There are occasions when a <code>RowSet</code> object has a need to provide a degree
44+ * of filtering to its contents. One possible solution is to provide
45+ * a query language for all standard <code>RowSet</code> implementations; however,
46+ * this is an impractical approach for lightweight components such as disconnected
47+ * <code>RowSet</code>
48+ * objects. The <code>FilteredRowSet</code> interface seeks to address this need
49+ * without supplying a heavyweight query language along with the processing that
50+ * such a query language would require.
51+ * <p>
52+ * A JDBC <code>FilteredRowSet</code> standard implementation implements the
53+ * <code>RowSet</code> interfaces and extends the
54+ * <code>CachedRowSet</code><sup><font size=-2>TM</font></sup> class. The
55+ * <code>CachedRowSet</code> class provides a set of protected cursor manipulation
56+ * methods, which a <code>FilteredRowSet</code> implementation can override
57+ * to supply filtering support.
58+ *
59+ * <h3>2.0 Predicate Sharing</h3>
60+ *
61+ * If a <code>FilteredRowSet</code> implementation is shared using the
62+ * inherited <code>createShared</code> method in parent interfaces, the
63+ * <code>Predicate</code> should be shared without modification by all
64+ * <code>FilteredRowSet</code> instance clones.
65+ *
66+ * <h3>3.0 Usage</h3>
67+ * <p>
68+ * By implementing a <code>Predicate</code> (see example in <a href="Predicate.html">Predicate</a>
69+ * class JavaDoc), a <code>FilteredRowSet</code> could then be used as described
70+ * below.
71+ * <P>
72+ * <code>
73+ * <pre>
74+ * FilteredRowSet frs = new FilteredRowSetImpl();
75+ * frs.populate(rs);
76+ *
77+ * Range name = new Range("Alpha", "Bravo", "columnName");
78+ * frs.setFilter(name);
79+ *
80+ * frs.next() // only names from "Alpha" to "Bravo" will be returned
81+ * </pre>
82+ * </code>
83+ * In the example above, we initialize a <code>Range</code> object which
84+ * implements the <code>Predicate</code> interface. This object expresses
85+ * the following constraints: All rows outputted or modified from this
86+ * <code>FilteredRowSet</code> object must fall between the values 'Alpha' and
87+ * 'Bravo' both values inclusive, in the column 'columnName'. If a filter is
88+ * applied to a <code>FilteredRowSet</code> object that contains no data that
89+ * falls within the range of the filter, no rows are returned.
90+ * <p>
91+ * This framework allows multiple classes implementing predicates to be
92+ * used in combination to achieved the required filtering result with
93+ * out the need for query language processing.
94+ * <p>
95+ * <h3>4.0 Updating a <code>FilteredRowSet</code> Object</h3>
96+ * The predicate set on a <code>FilteredRowSet</code> object
97+ * applies a criterion on all rows in a
98+ * <code>RowSet</code> object to manage a subset of rows in a <code>RowSet</code>
99+ * object. This criterion governs the subset of rows that are visible and also
100+ * defines which rows can be modified, deleted or inserted.
101+ * <p>
102+ * Therefore, the predicate set on a <code>FilteredRowSet</code> object must be
103+ * considered as bi-directional and the set criterion as the gating mechanism
104+ * for all views and updates to the <code>FilteredRowSet</code> object. Any attempt
105+ * to update the <code>FilteredRowSet</code> that violates the criterion will
106+ * result in a <code>SQLException</code> object being thrown.
107+ * <p>
108+ * The <code>FilteredRowSet</code> range criterion can be modified by applying
109+ * a new <code>Predicate</code> object to the <code>FilteredRowSet</code>
110+ * instance at any time. This is possible if no additional references to the
111+ * <code>FilteredRowSet</code> object are detected. A new filter has has an
112+ * immediate effect on criterion enforcement within the
113+ * <code>FilteredRowSet</code> object, and all subsequent views and updates will be
114+ * subject to similar enforcement.
115+ * <p>
116+ * <h3>5.0 Behavior of Rows Outside the Filter</h3>
117+ * Rows that fall outside of the filter set on a <code>FilteredRowSet</code>
118+ * object cannot be modified until the filter is removed or a
119+ * new filter is applied.
120+ * <p>
121+ * Furthermore, only rows that fall within the bounds of a filter will be
122+ * synchronized with the data source.
123+ *
124+ * @author Jonathan Bruce
125+ */
126+
127+public interface FilteredRowSet extends WebRowSet {
128+
129+ /**
130+ * Applies the given <code>Predicate</code> object to this
131+ * <code>FilteredRowSet</code>
132+ * object. The filter applies controls both to inbound and outbound views,
133+ * constraining which rows are visible and which
134+ * rows can be manipulated.
135+ * <p>
136+ * A new <code>Predicate</code> object may be set at any time. This has the
137+ * effect of changing constraints on the <code>RowSet</code> object's data.
138+ * In addition, modifying the filter at runtime presents issues whereby
139+ * multiple components may be operating on one <code>FilteredRowSet</code> object.
140+ * Application developers must take responsibility for managing multiple handles
141+ * to <code>FilteredRowSet</code> objects when their underling <code>Predicate</code>
142+ * objects change.
143+ *
144+ * @param p a <code>Predicate</code> object defining the filter for this
145+ * <code>FilteredRowSet</code> object. Setting a <b>null</b> value
146+ * will clear the predicate, allowing all rows to become visible.
147+ *
148+ * @throws SQLException if an error occurs when setting the
149+ * <code>Predicate</code> object
150+ */
151+ public void setFilter(Predicate p) throws SQLException;
152+
153+ /**
154+ * Retrieves the active filter for this <code>FilteredRowSet</code> object.
155+ *
156+ * @return p the <code>Predicate</code> for this <code>FilteredRowSet</code>
157+ * object; <code>null</code> if no filter has been set.
158+ */
159+ public Predicate getFilter() ;
160+}