/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.empire.spring;

import org.apache.empire.db.DBReader;

/**
 * Callback interface to use with {@link EmpireTemplate}'s query methods.
 * Implementations of this interface perform the actual work of extracting
 * results from a {@link DBReader}.
 * 
 * This class is the Empire equivalent of Spring's
 * {@link org.springframework.jdbc.core.ResultSetExtractor}.
 */

public interface DBReaderExtractor<K> {

	/**
	 * Implementations must implement this method to process the entire
	 * DBReader. Unlike DBRecordMapper and DBRecordCallbackHandler it's the
	 * developer's response to iterate through the reader calling reader.next();
	 * 
	 * @param reader
	 *            to process
	 * @return the result object, can be null
	 */

	K process(DBReader reader);

}