2362N/A * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 2362N/A * published by the Free Software Foundation. Oracle designates this 0N/A * particular file as subject to the "Classpath" exception as provided 2362N/A * by Oracle in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2362N/A * or visit www.oracle.com if you need additional information or have any 0N/A * The standard interface that all standard implementations of 0N/A * <code>FilteredRowSet</code> must implement. The <code>FilteredRowSetImpl</code> class 0N/A * provides the reference implementation which may be extended if required. 0N/A * Alternatively, a vendor is free to implement its own version 0N/A * by implementing this interface. 0N/A * <h3>1.0 Background</h3> 0N/A * There are occasions when a <code>RowSet</code> object has a need to provide a degree 0N/A * of filtering to its contents. One possible solution is to provide 0N/A * a query language for all standard <code>RowSet</code> implementations; however, 0N/A * this is an impractical approach for lightweight components such as disconnected 0N/A * <code>RowSet</code> 0N/A * objects. The <code>FilteredRowSet</code> interface seeks to address this need 0N/A * without supplying a heavyweight query language along with the processing that 0N/A * such a query language would require. 0N/A * A JDBC <code>FilteredRowSet</code> standard implementation implements the 0N/A * <code>RowSet</code> interfaces and extends the 0N/A * <code>CachedRowSet</code><sup><font size=-2>TM</font></sup> class. The 0N/A * <code>CachedRowSet</code> class provides a set of protected cursor manipulation 0N/A * methods, which a <code>FilteredRowSet</code> implementation can override 0N/A * to supply filtering support. 0N/A * <h3>2.0 Predicate Sharing</h3> 0N/A * If a <code>FilteredRowSet</code> implementation is shared using the 0N/A * inherited <code>createShared</code> method in parent interfaces, the 0N/A * <code>Predicate</code> should be shared without modification by all 0N/A * <code>FilteredRowSet</code> instance clones. 0N/A * <h3>3.0 Usage</h3> 0N/A * By implementing a <code>Predicate</code> (see example in <a href="Predicate.html">Predicate</a> 0N/A * class JavaDoc), a <code>FilteredRowSet</code> could then be used as described 0N/A * FilteredRowSet frs = new FilteredRowSetImpl(); 0N/A * Range name = new Range("Alpha", "Bravo", "columnName"); 0N/A * frs.setFilter(name); 0N/A * frs.next() // only names from "Alpha" to "Bravo" will be returned 0N/A * In the example above, we initialize a <code>Range</code> object which 0N/A * implements the <code>Predicate</code> interface. This object expresses 0N/A * the following constraints: All rows outputted or modified from this 0N/A * <code>FilteredRowSet</code> object must fall between the values 'Alpha' and 0N/A * 'Bravo' both values inclusive, in the column 'columnName'. If a filter is 0N/A * applied to a <code>FilteredRowSet</code> object that contains no data that 0N/A * falls within the range of the filter, no rows are returned. 0N/A * This framework allows multiple classes implementing predicates to be 0N/A * used in combination to achieved the required filtering result with 0N/A * out the need for query language processing. 0N/A * <h3>4.0 Updating a <code>FilteredRowSet</code> Object</h3> 0N/A * The predicate set on a <code>FilteredRowSet</code> object 0N/A * applies a criterion on all rows in a 0N/A * <code>RowSet</code> object to manage a subset of rows in a <code>RowSet</code> 0N/A * object. This criterion governs the subset of rows that are visible and also 0N/A * defines which rows can be modified, deleted or inserted. 0N/A * Therefore, the predicate set on a <code>FilteredRowSet</code> object must be 0N/A * considered as bi-directional and the set criterion as the gating mechanism 0N/A * for all views and updates to the <code>FilteredRowSet</code> object. Any attempt 0N/A * to update the <code>FilteredRowSet</code> that violates the criterion will 0N/A * result in a <code>SQLException</code> object being thrown. 0N/A * The <code>FilteredRowSet</code> range criterion can be modified by applying 0N/A * a new <code>Predicate</code> object to the <code>FilteredRowSet</code> 0N/A * instance at any time. This is possible if no additional references to the 0N/A * <code>FilteredRowSet</code> object are detected. A new filter has has an 0N/A * immediate effect on criterion enforcement within the 0N/A * <code>FilteredRowSet</code> object, and all subsequent views and updates will be 0N/A * subject to similar enforcement. 0N/A * <h3>5.0 Behavior of Rows Outside the Filter</h3> 0N/A * Rows that fall outside of the filter set on a <code>FilteredRowSet</code> 0N/A * object cannot be modified until the filter is removed or a 0N/A * new filter is applied. 0N/A * Furthermore, only rows that fall within the bounds of a filter will be 0N/A * synchronized with the data source. 0N/A * @author Jonathan Bruce 0N/A * Applies the given <code>Predicate</code> object to this 0N/A * <code>FilteredRowSet</code> 0N/A * object. The filter applies controls both to inbound and outbound views, 0N/A * constraining which rows are visible and which 0N/A * rows can be manipulated. 0N/A * A new <code>Predicate</code> object may be set at any time. This has the 0N/A * effect of changing constraints on the <code>RowSet</code> object's data. 0N/A * In addition, modifying the filter at runtime presents issues whereby 0N/A * multiple components may be operating on one <code>FilteredRowSet</code> object. 0N/A * Application developers must take responsibility for managing multiple handles 0N/A * to <code>FilteredRowSet</code> objects when their underling <code>Predicate</code> 0N/A * @param p a <code>Predicate</code> object defining the filter for this 0N/A * <code>FilteredRowSet</code> object. Setting a <b>null</b> value 0N/A * will clear the predicate, allowing all rows to become visible. 0N/A * @throws SQLException if an error occurs when setting the 0N/A * <code>Predicate</code> object 0N/A * Retrieves the active filter for this <code>FilteredRowSet</code> object. 0N/A * @return p the <code>Predicate</code> for this <code>FilteredRowSet</code> 0N/A * object; <code>null</code> if no filter has been set.