/*

 * Copyright (c) 2000, 2001, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package javax.sql;

import java.sql.*;

/**

 * The facility that a disconnected <code>RowSet</code> object calls on

 * to populate itself with rows of data. A reader (an object implementing the

 * <code>RowSetReader</code> interface) may be registered with

 * a <code>RowSet</code> object that supports the reader/writer paradigm.

 * When the <code>RowSet</code> object's <code>execute</code> method is

 * called, it in turn calls the reader's <code>readData</code> method.

 *

 * @since 1.4

 */

public interface RowSetReader {

  /**

   * Reads the new contents of the calling <code>RowSet</code> object.

   * In order to call this method, a <code>RowSet</code>

   * object must have implemented the <code>RowSetInternal</code> interface

   * and registered this <code>RowSetReader</code> object as its reader.

   * The <code>readData</code>  method is invoked internally

   * by the <code>RowSet.execute</code> method for rowsets that support the

   * reader/writer paradigm.

   *

   * <P>The <code>readData</code> method adds rows to the caller.

   * It can be implemented in a wide variety of ways and can even

   * populate the caller with rows from a nonrelational data source.

   * In general, a reader may invoke any of the rowset's methods,

   * with one exception. Calling the method <code>execute</code> will

   * cause an <code>SQLException</code> to be thrown

   * because <code>execute</code> may not be called recursively.  Also,

   * when a reader invokes <code>RowSet</code> methods, no listeners

   * are notified; that is, no <code>RowSetEvent</code> objects are

   * generated and no <code>RowSetListener</code> methods are invoked.

   * This is true because listeners are already being notified by the method

   * <code>execute</code>.

   *

   * @param caller the <code>RowSet</code> object (1) that has implemented the

   *         <code>RowSetInternal</code> interface, (2) with which this reader is

   *        registered, and (3) whose <code>execute</code> method called this reader

   * @exception SQLException if a database access error occurs or this method

   *            invokes the <code>RowSet.execute</code> method

   */

  void readData(RowSetInternal caller) throws SQLException;

}