/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.springframework.jdbc.object;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Map;

import javax.sql.DataSource;

import org.springframework.lang.Nullable;

Reusable query in which concrete subclasses must implement the abstract
mapRow(ResultSet, int) method to convert each row of the JDBC ResultSet
into an object.
Simplifies MappingSqlQueryWithParameters API by dropping parameters and
context. Most subclasses won't care about parameters. If you don't use
contextual information, subclass this instead of MappingSqlQueryWithParameters.
Author:
Rod Johnson, Thomas Risberg, Jean-Pierre Pawlak
Type parameters:
<T> – the result type
See Also:
MappingSqlQueryWithParameters/**
 * Reusable query in which concrete subclasses must implement the abstract
 * mapRow(ResultSet, int) method to convert each row of the JDBC ResultSet
 * into an object.
 *
 * <p>Simplifies MappingSqlQueryWithParameters API by dropping parameters and
 * context. Most subclasses won't care about parameters. If you don't use
 * contextual information, subclass this instead of MappingSqlQueryWithParameters.
 *
 * @author Rod Johnson
 * @author Thomas Risberg
 * @author Jean-Pierre Pawlak
 * @param <T> the result type
 * @see MappingSqlQueryWithParameters
 */
public abstract class MappingSqlQuery<T> extends MappingSqlQueryWithParameters<T> {

	
Constructor that allows use as a JavaBean.
/**
	 * Constructor that allows use as a JavaBean.
	 */
	public MappingSqlQuery() {
	}

	
Convenient constructor with DataSource and SQL string.
Params:
ds – the DataSource to use to obtain connections
sql – the SQL to run/**
	 * Convenient constructor with DataSource and SQL string.
	 * @param ds the DataSource to use to obtain connections
	 * @param sql the SQL to run
	 */
	public MappingSqlQuery(DataSource ds, String sql) {
		super(ds, sql);
	}


	
This method is implemented to invoke the simpler mapRow
template method, ignoring parameters.
See Also:
mapRow(ResultSet, int)/**
	 * This method is implemented to invoke the simpler mapRow
	 * template method, ignoring parameters.
	 * @see #mapRow(ResultSet, int)
	 */
	@Override
	@Nullable
	protected final T mapRow(ResultSet rs, int rowNum, @Nullable Object[] parameters, @Nullable Map<?, ?> context)
			throws SQLException {

		return mapRow(rs, rowNum);
	}

	
Subclasses must implement this method to convert each row of the
ResultSet into an object of the result type.
Subclasses of this class, as opposed to direct subclasses of
MappingSqlQueryWithParameters, don't need to concern themselves
with the parameters to the execute method of the query object.
Params:
rs – the ResultSet we're working through
rowNum – row number (from 0) we're up to
Throws:
SQLException – if there's an error extracting data.
Subclasses can simply not catch SQLExceptions, relying on the
framework to clean up.
Returns:
an object of the result type/**
	 * Subclasses must implement this method to convert each row of the
	 * ResultSet into an object of the result type.
	 * <p>Subclasses of this class, as opposed to direct subclasses of
	 * MappingSqlQueryWithParameters, don't need to concern themselves
	 * with the parameters to the execute method of the query object.
	 * @param rs the ResultSet we're working through
	 * @param rowNum row number (from 0) we're up to
	 * @return an object of the result type
	 * @throws SQLException if there's an error extracting data.
	 * Subclasses can simply not catch SQLExceptions, relying on the
	 * framework to clean up.
	 */
	@Nullable
	protected abstract T mapRow(ResultSet rs, int rowNum) throws SQLException;

}