/*
 * Copyright 2002-2013 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
 *
 *      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.springframework.jdbc.core;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import javax.sql.DataSource;

import org.springframework.dao.DataAccessException;
import org.springframework.dao.InvalidDataAccessApiUsageException;
import org.springframework.dao.support.DataAccessUtils;
import org.springframework.jdbc.SQLWarningException;
import org.springframework.jdbc.datasource.ConnectionProxy;
import org.springframework.jdbc.datasource.DataSourceUtils;
import org.springframework.jdbc.support.JdbcAccessor;
import org.springframework.jdbc.support.JdbcUtils;
import org.springframework.jdbc.support.KeyHolder;
import org.springframework.jdbc.support.nativejdbc.NativeJdbcExtractor;
import org.springframework.jdbc.support.rowset.SqlRowSet;
import org.springframework.util.Assert;
import org.springframework.util.LinkedCaseInsensitiveMap;

/**
 * <b>This is the central class in the JDBC core package.</b>
 * It simplifies the use of JDBC and helps to avoid common errors.
 * It executes core JDBC workflow, leaving application code to provide SQL
 * and extract results. This class executes SQL queries or updates, initiating
 * iteration over ResultSets and catching JDBC exceptions and translating
 * them to the generic, more informative exception hierarchy defined in the
 * {@code org.springframework.dao} package.
 *
 * <p>Code using this class need only implement callback interfaces, giving
 * them a clearly defined contract. The {@link PreparedStatementCreator} callback
 * interface creates a prepared statement given a Connection, providing SQL and
 * any necessary parameters. The {@link ResultSetExtractor} interface extracts
 * values from a ResultSet. See also {@link PreparedStatementSetter} and
 * {@link RowMapper} for two popular alternative callback interfaces.
 *
 * <p>Can be used within a service implementation via direct instantiation
 * with a DataSource reference, or get prepared in an application context
 * and given to services as bean reference. Note: The DataSource should
 * always be configured as a bean in the application context, in the first case
 * given to the service directly, in the second case to the prepared template.
 *
 * <p>Because this class is parameterizable by the callback interfaces and
 * the {@link org.springframework.jdbc.support.SQLExceptionTranslator}
 * interface, there should be no need to subclass it.
 *
 * <p>All SQL operations performed by this class are logged at debug level,
 * using "org.springframework.jdbc.core.JdbcTemplate" as log category.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @author Thomas Risberg
 * @since May 3, 2001
 * @see PreparedStatementCreator
 * @see PreparedStatementSetter
 * @see CallableStatementCreator
 * @see PreparedStatementCallback
 * @see CallableStatementCallback
 * @see ResultSetExtractor
 * @see RowCallbackHandler
 * @see RowMapper
 * @see org.springframework.jdbc.support.SQLExceptionTranslator
 */
public class JdbcTemplate extends JdbcAccessor implements JdbcOperations {

	private static final String RETURN_RESULT_SET_PREFIX = "#result-set-";

	private static final String RETURN_UPDATE_COUNT_PREFIX = "#update-count-";


	/** Custom NativeJdbcExtractor */
	private NativeJdbcExtractor nativeJdbcExtractor;

	/** If this variable is false, we will throw exceptions on SQL warnings */
	private boolean ignoreWarnings = true;

	/**
	 * If this variable is set to a non-zero value, it will be used for setting the
	 * fetchSize property on statements used for query processing.
	 */
	private int fetchSize = 0;

	/**
	 * If this variable is set to a non-zero value, it will be used for setting the
	 * maxRows property on statements used for query processing.
	 */
	private int maxRows = 0;

	/**
	 * If this variable is set to a non-zero value, it will be used for setting the
	 * queryTimeout property on statements used for query processing.
	 */
	private int queryTimeout = 0;

	/**
	 * If this variable is set to true then all results checking will be bypassed for any
	 * callable statement processing.  This can be used to avoid a bug in some older Oracle
	 * JDBC drivers like 10.1.0.2.
	 */
	private boolean skipResultsProcessing = false;

	/**
	 * If this variable is set to true then all results from a stored procedure call
	 * that don't have a corresponding SqlOutParameter declaration will be bypassed.
	 * All other results processing will be take place unless the variable
	 * {@code skipResultsProcessing} is set to {@code true}.
	 */
	private boolean skipUndeclaredResults = false;

	/**
	 * If this variable is set to true then execution of a CallableStatement will return
	 * the results in a Map that uses case insensitive names for the parameters if
	 * Commons Collections is available on the classpath.
	 */
	private boolean resultsMapCaseInsensitive = false;


	/**
	 * Construct a new JdbcTemplate for bean usage.
	 * <p>Note: The DataSource has to be set before using the instance.
	 * @see #setDataSource
	 */
	public JdbcTemplate() {
	}

	/**
	 * Construct a new JdbcTemplate, given a DataSource to obtain connections from.
	 * <p>Note: This will not trigger initialization of the exception translator.
	 * @param dataSource the JDBC DataSource to obtain connections from
	 */
	public JdbcTemplate(DataSource dataSource) {
		setDataSource(dataSource);
		afterPropertiesSet();
	}

	/**
	 * Construct a new JdbcTemplate, given a DataSource to obtain connections from.
	 * <p>Note: Depending on the "lazyInit" flag, initialization of the exception translator
	 * will be triggered.
	 * @param dataSource the JDBC DataSource to obtain connections from
	 * @param lazyInit whether to lazily initialize the SQLExceptionTranslator
	 */
	public JdbcTemplate(DataSource dataSource, boolean lazyInit) {
		setDataSource(dataSource);
		setLazyInit(lazyInit);
		afterPropertiesSet();
	}


	/**
	 * Set a NativeJdbcExtractor to extract native JDBC objects from wrapped handles.
	 * Useful if native Statement and/or ResultSet handles are expected for casting
	 * to database-specific implementation classes, but a connection pool that wraps
	 * JDBC objects is used (note: <i>any</i> pool will return wrapped Connections).
	 */
	public void setNativeJdbcExtractor(NativeJdbcExtractor extractor) {
		this.nativeJdbcExtractor = extractor;
	}

	/**
	 * Return the current NativeJdbcExtractor implementation.
	 */
	public NativeJdbcExtractor getNativeJdbcExtractor() {
		return this.nativeJdbcExtractor;
	}

	/**
	 * Set whether or not we want to ignore SQLWarnings.
	 * <p>Default is "true", swallowing and logging all warnings. Switch this flag
	 * to "false" to make the JdbcTemplate throw a SQLWarningException instead.
	 * @see java.sql.SQLWarning
	 * @see org.springframework.jdbc.SQLWarningException
	 * @see #handleWarnings
	 */
	public void setIgnoreWarnings(boolean ignoreWarnings) {
		this.ignoreWarnings = ignoreWarnings;
	}

	/**
	 * Return whether or not we ignore SQLWarnings.
	 */
	public boolean isIgnoreWarnings() {
		return this.ignoreWarnings;
	}

	/**
	 * Set the fetch size for this JdbcTemplate. This is important for processing
	 * large result sets: Setting this higher than the default value will increase
	 * processing speed at the cost of memory consumption; setting this lower can
	 * avoid transferring row data that will never be read by the application.
	 * <p>Default is 0, indicating to use the JDBC driver's default.
	 * @see java.sql.Statement#setFetchSize
	 */
	public void setFetchSize(int fetchSize) {
		this.fetchSize = fetchSize;
	}

	/**
	 * Return the fetch size specified for this JdbcTemplate.
	 */
	public int getFetchSize() {
		return this.fetchSize;
	}

	/**
	 * Set the maximum number of rows for this JdbcTemplate. This is important
	 * for processing subsets of large result sets, avoiding to read and hold
	 * the entire result set in the database or in the JDBC driver if we're
	 * never interested in the entire result in the first place (for example,
	 * when performing searches that might return a large number of matches).
	 * <p>Default is 0, indicating to use the JDBC driver's default.
	 * @see java.sql.Statement#setMaxRows
	 */
	public void setMaxRows(int maxRows) {
		this.maxRows = maxRows;
	}

	/**
	 * Return the maximum number of rows specified for this JdbcTemplate.
	 */
	public int getMaxRows() {
		return this.maxRows;
	}

	/**
	 * Set the query timeout for statements that this JdbcTemplate executes.
	 * <p>Default is 0, indicating to use the JDBC driver's default.
	 * <p>Note: Any timeout specified here will be overridden by the remaining
	 * transaction timeout when executing within a transaction that has a
	 * timeout specified at the transaction level.
	 * @see java.sql.Statement#setQueryTimeout
	 */
	public void setQueryTimeout(int queryTimeout) {
		this.queryTimeout = queryTimeout;
	}

	/**
	 * Return the query timeout for statements that this JdbcTemplate executes.
	 */
	public int getQueryTimeout() {
		return this.queryTimeout;
	}

	/**
	 * Set whether results processing should be skipped. Can be used to optimize callable
	 * statement processing when we know that no results are being passed back - the processing
	 * of out parameter will still take place. This can be used to avoid a bug in some older
	 * Oracle JDBC drivers like 10.1.0.2.
	 */
	public void setSkipResultsProcessing(boolean skipResultsProcessing) {
		this.skipResultsProcessing = skipResultsProcessing;
	}

	/**
	 * Return whether results processing should be skipped.
	 */
	public boolean isSkipResultsProcessing() {
		return this.skipResultsProcessing;
	}

	/**
	 * Set whether undeclared results should be skipped.
	 */
	public void setSkipUndeclaredResults(boolean skipUndeclaredResults) {
		this.skipUndeclaredResults = skipUndeclaredResults;
	}

	/**
	 * Return whether undeclared results should be skipped.
	 */
	public boolean isSkipUndeclaredResults() {
		return this.skipUndeclaredResults;
	}

	/**
	 * Set whether execution of a CallableStatement will return the results in a Map
	 * that uses case insensitive names for the parameters.
	 */
	public void setResultsMapCaseInsensitive(boolean resultsMapCaseInsensitive) {
		this.resultsMapCaseInsensitive = resultsMapCaseInsensitive;
	}

	/**
	 * Return whether execution of a CallableStatement will return the results in a Map
	 * that uses case insensitive names for the parameters.
	 */
	public boolean isResultsMapCaseInsensitive() {
		return this.resultsMapCaseInsensitive;
	}


	//-------------------------------------------------------------------------
	// Methods dealing with a plain java.sql.Connection
	//-------------------------------------------------------------------------

	public <T> T execute(ConnectionCallback<T> action) throws DataAccessException {
		Assert.notNull(action, "Callback object must not be null");

		Connection con = DataSourceUtils.getConnection(getDataSource());
		try {
			Connection conToUse = con;
			if (this.nativeJdbcExtractor != null) {
				// Extract native JDBC Connection, castable to OracleConnection or the like.
				conToUse = this.nativeJdbcExtractor.getNativeConnection(con);
			}
			else {
				// Create close-suppressing Connection proxy, also preparing returned Statements.
				conToUse = createConnectionProxy(con);
			}
			return action.doInConnection(conToUse);
		}
		catch (SQLException ex) {
			// Release Connection early, to avoid potential connection pool deadlock
			// in the case when the exception translator hasn't been initialized yet.
			DataSourceUtils.releaseConnection(con, getDataSource());
			con = null;
			throw getExceptionTranslator().translate("ConnectionCallback", getSql(action), ex);
		}
		finally {
			DataSourceUtils.releaseConnection(con, getDataSource());
		}
	}

	/**
	 * Create a close-suppressing proxy for the given JDBC Connection.
	 * Called by the {@code execute} method.
	 * <p>The proxy also prepares returned JDBC Statements, applying
	 * statement settings such as fetch size, max rows, and query timeout.
	 * @param con the JDBC Connection to create a proxy for
	 * @return the Connection proxy
	 * @see java.sql.Connection#close()
	 * @see #execute(ConnectionCallback)
	 * @see #applyStatementSettings
	 */
	protected Connection createConnectionProxy(Connection con) {
		return (Connection) Proxy.newProxyInstance(
				ConnectionProxy.class.getClassLoader(),
				new Class[] {ConnectionProxy.class},
				new CloseSuppressingInvocationHandler(con));
	}


	//-------------------------------------------------------------------------
	// Methods dealing with static SQL (java.sql.Statement)
	//-------------------------------------------------------------------------

	public <T> T execute(StatementCallback<T> action) throws DataAccessException {
		Assert.notNull(action, "Callback object must not be null");

		Connection con = DataSourceUtils.getConnection(getDataSource());
		Statement stmt = null;
		try {
			Connection conToUse = con;
			if (this.nativeJdbcExtractor != null &&
					this.nativeJdbcExtractor.isNativeConnectionNecessaryForNativeStatements()) {
				conToUse = this.nativeJdbcExtractor.getNativeConnection(con);
			}
			stmt = conToUse.createStatement();
			applyStatementSettings(stmt);
			Statement stmtToUse = stmt;
			if (this.nativeJdbcExtractor != null) {
				stmtToUse = this.nativeJdbcExtractor.getNativeStatement(stmt);
			}
			T result = action.doInStatement(stmtToUse);
			handleWarnings(stmt);
			return result;
		}
		catch (SQLException ex) {
			// Release Connection early, to avoid potential connection pool deadlock
			// in the case when the exception translator hasn't been initialized yet.
			JdbcUtils.closeStatement(stmt);
			stmt = null;
			DataSourceUtils.releaseConnection(con, getDataSource());
			con = null;
			throw getExceptionTranslator().translate("StatementCallback", getSql(action), ex);
		}
		finally {
			JdbcUtils.closeStatement(stmt);
			DataSourceUtils.releaseConnection(con, getDataSource());
		}
	}

	public void execute(final String sql) throws DataAccessException {
		if (logger.isDebugEnabled()) {
			logger.debug("Executing SQL statement [" + sql + "]");
		}
		class ExecuteStatementCallback implements StatementCallback<Object>, SqlProvider {
			public Object doInStatement(Statement stmt) throws SQLException {
				stmt.execute(sql);
				return null;
			}
			public String getSql() {
				return sql;
			}
		}
		execute(new ExecuteStatementCallback());
	}

	public <T> T query(final String sql, final ResultSetExtractor<T> rse) throws DataAccessException {
		Assert.notNull(sql, "SQL must not be null");
		Assert.notNull(rse, "ResultSetExtractor must not be null");
		if (logger.isDebugEnabled()) {
			logger.debug("Executing SQL query [" + sql + "]");
		}
		class QueryStatementCallback implements StatementCallback<T>, SqlProvider {
			public T doInStatement(Statement stmt) throws SQLException {
				ResultSet rs = null;
				try {
					rs = stmt.executeQuery(sql);
					ResultSet rsToUse = rs;
					if (nativeJdbcExtractor != null) {
						rsToUse = nativeJdbcExtractor.getNativeResultSet(rs);
					}
					return rse.extractData(rsToUse);
				}
				finally {
					JdbcUtils.closeResultSet(rs);
				}
			}
			public String getSql() {
				return sql;
			}
		}
		return execute(new QueryStatementCallback());
	}

	public void query(String sql, RowCallbackHandler rch) throws DataAccessException {
		query(sql, new RowCallbackHandlerResultSetExtractor(rch));
	}

	public <T> List<T> query(String sql, RowMapper<T> rowMapper) throws DataAccessException {
		return query(sql, new RowMapperResultSetExtractor<T>(rowMapper));
	}

	public Map<String, Object> queryForMap(String sql) throws DataAccessException {
		return queryForObject(sql, getColumnMapRowMapper());
	}

	public <T> T queryForObject(String sql, RowMapper<T> rowMapper) throws DataAccessException {
		List<T> results = query(sql, rowMapper);
		return DataAccessUtils.requiredSingleResult(results);
	}

	public <T> T queryForObject(String sql, Class<T> requiredType) throws DataAccessException {
		return queryForObject(sql, getSingleColumnRowMapper(requiredType));
	}

	@Deprecated
	public long queryForLong(String sql) throws DataAccessException {
		Number number = queryForObject(sql, Long.class);
		return (number != null ? number.longValue() : 0);
	}

	@Deprecated
	public int queryForInt(String sql) throws DataAccessException {
		Number number = queryForObject(sql, Integer.class);
		return (number != null ? number.intValue() : 0);
	}

	public <T> List<T> queryForList(String sql, Class<T> elementType) throws DataAccessException {
		return query(sql, getSingleColumnRowMapper(elementType));
	}

	public List<Map<String, Object>> queryForList(String sql) throws DataAccessException {
		return query(sql, getColumnMapRowMapper());
	}

	public SqlRowSet queryForRowSet(String sql) throws DataAccessException {
		return query(sql, new SqlRowSetResultSetExtractor());
	}

	public int update(final String sql) throws DataAccessException {
		Assert.notNull(sql, "SQL must not be null");
		if (logger.isDebugEnabled()) {
			logger.debug("Executing SQL update [" + sql + "]");
		}
		class UpdateStatementCallback implements StatementCallback<Integer>, SqlProvider {
			public Integer doInStatement(Statement stmt) throws SQLException {
				int rows = stmt.executeUpdate(sql);
				if (logger.isDebugEnabled()) {
					logger.debug("SQL update affected " + rows + " rows");
				}
				return rows;
			}
			public String getSql() {
				return sql;
			}
		}
		return execute(new UpdateStatementCallback());
	}

	public int[] batchUpdate(final String[] sql) throws DataAccessException {
		Assert.notEmpty(sql, "SQL array must not be empty");
		if (logger.isDebugEnabled()) {
			logger.debug("Executing SQL batch update of " + sql.length + " statements");
		}
		class BatchUpdateStatementCallback implements StatementCallback<int[]>, SqlProvider {
			private String currSql;
			public int[] doInStatement(Statement stmt) throws SQLException, DataAccessException {
				int[] rowsAffected = new int[sql.length];
				if (JdbcUtils.supportsBatchUpdates(stmt.getConnection())) {
					for (String sqlStmt : sql) {
						this.currSql = sqlStmt;
						stmt.addBatch(sqlStmt);
					}
					rowsAffected = stmt.executeBatch();
				}
				else {
					for (int i = 0; i < sql.length; i++) {
						this.currSql = sql[i];
						if (!stmt.execute(sql[i])) {
							rowsAffected[i] = stmt.getUpdateCount();
						}
						else {
							throw new InvalidDataAccessApiUsageException("Invalid batch SQL statement: " + sql[i]);
						}
					}
				}
				return rowsAffected;
			}
			public String getSql() {
				return this.currSql;
			}
		}
		return execute(new BatchUpdateStatementCallback());
	}


	//-------------------------------------------------------------------------
	// Methods dealing with prepared statements
	//-------------------------------------------------------------------------

	public <T> T execute(PreparedStatementCreator psc, PreparedStatementCallback<T> action)
			throws DataAccessException {

		Assert.notNull(psc, "PreparedStatementCreator must not be null");
		Assert.notNull(action, "Callback object must not be null");
		if (logger.isDebugEnabled()) {
			String sql = getSql(psc);
			logger.debug("Executing prepared SQL statement" + (sql != null ? " [" + sql + "]" : ""));
		}

		Connection con = DataSourceUtils.getConnection(getDataSource());
		PreparedStatement ps = null;
		try {
			Connection conToUse = con;
			if (this.nativeJdbcExtractor != null &&
					this.nativeJdbcExtractor.isNativeConnectionNecessaryForNativePreparedStatements()) {
				conToUse = this.nativeJdbcExtractor.getNativeConnection(con);
			}
			ps = psc.createPreparedStatement(conToUse);
			applyStatementSettings(ps);
			PreparedStatement psToUse = ps;
			if (this.nativeJdbcExtractor != null) {
				psToUse = this.nativeJdbcExtractor.getNativePreparedStatement(ps);
			}
			T result = action.doInPreparedStatement(psToUse);
			handleWarnings(ps);
			return result;
		}
		catch (SQLException ex) {
			// Release Connection early, to avoid potential connection pool deadlock
			// in the case when the exception translator hasn't been initialized yet.
			if (psc instanceof ParameterDisposer) {
				((ParameterDisposer) psc).cleanupParameters();
			}
			String sql = getSql(psc);
			psc = null;
			JdbcUtils.closeStatement(ps);
			ps = null;
			DataSourceUtils.releaseConnection(con, getDataSource());
			con = null;
			throw getExceptionTranslator().translate("PreparedStatementCallback", sql, ex);
		}
		finally {
			if (psc instanceof ParameterDisposer) {
				((ParameterDisposer) psc).cleanupParameters();
			}
			JdbcUtils.closeStatement(ps);
			DataSourceUtils.releaseConnection(con, getDataSource());
		}
	}

	public <T> T execute(String sql, PreparedStatementCallback<T> action) throws DataAccessException {
		return execute(new SimplePreparedStatementCreator(sql), action);
	}

	/**
	 * Query using a prepared statement, allowing for a PreparedStatementCreator
	 * and a PreparedStatementSetter. Most other query methods use this method,
	 * but application code will always work with either a creator or a setter.
	 * @param psc Callback handler that can create a PreparedStatement given a
	 * Connection
	 * @param pss object that knows how to set values on the prepared statement.
	 * If this is null, the SQL will be assumed to contain no bind parameters.
	 * @param rse object that will extract results.
	 * @return an arbitrary result object, as returned by the ResultSetExtractor
	 * @throws DataAccessException if there is any problem
	 */
	public <T> T query(
			PreparedStatementCreator psc, final PreparedStatementSetter pss, final ResultSetExtractor<T> rse)
			throws DataAccessException {

		Assert.notNull(rse, "ResultSetExtractor must not be null");
		logger.debug("Executing prepared SQL query");

		return execute(psc, new PreparedStatementCallback<T>() {
			public T doInPreparedStatement(PreparedStatement ps) throws SQLException {
				ResultSet rs = null;
				try {
					if (pss != null) {
						pss.setValues(ps);
					}
					rs = ps.executeQuery();
					ResultSet rsToUse = rs;
					if (nativeJdbcExtractor != null) {
						rsToUse = nativeJdbcExtractor.getNativeResultSet(rs);
					}
					return rse.extractData(rsToUse);
				}
				finally {
					JdbcUtils.closeResultSet(rs);
					if (pss instanceof ParameterDisposer) {
						((ParameterDisposer) pss).cleanupParameters();
					}
				}
			}
		});
	}

	public <T> T query(PreparedStatementCreator psc, ResultSetExtractor<T> rse) throws DataAccessException {
		return query(psc, null, rse);
	}

	public <T> T query(String sql, PreparedStatementSetter pss, ResultSetExtractor<T> rse) throws DataAccessException {
		return query(new SimplePreparedStatementCreator(sql), pss, rse);
	}

	public <T> T query(String sql, Object[] args, int[] argTypes, ResultSetExtractor<T> rse) throws DataAccessException {
		return query(sql, newArgTypePreparedStatementSetter(args, argTypes), rse);
	}

	public <T> T query(String sql, Object[] args, ResultSetExtractor<T> rse) throws DataAccessException {
		return query(sql, newArgPreparedStatementSetter(args), rse);
	}

	public <T> T query(String sql, ResultSetExtractor<T> rse, Object... args) throws DataAccessException {
		return query(sql, newArgPreparedStatementSetter(args), rse);
	}

	public void query(PreparedStatementCreator psc, RowCallbackHandler rch) throws DataAccessException {
		query(psc, new RowCallbackHandlerResultSetExtractor(rch));
	}

	public void query(String sql, PreparedStatementSetter pss, RowCallbackHandler rch) throws DataAccessException {
		query(sql, pss, new RowCallbackHandlerResultSetExtractor(rch));
	}

	public void query(String sql, Object[] args, int[] argTypes, RowCallbackHandler rch) throws DataAccessException {
		query(sql, newArgTypePreparedStatementSetter(args, argTypes), rch);
	}

	public void query(String sql, Object[] args, RowCallbackHandler rch) throws DataAccessException {
		query(sql, newArgPreparedStatementSetter(args), rch);
	}

	public void query(String sql, RowCallbackHandler rch, Object... args) throws DataAccessException {
		query(sql, newArgPreparedStatementSetter(args), rch);
	}

	public <T> List<T> query(PreparedStatementCreator psc, RowMapper<T> rowMapper) throws DataAccessException {
		return query(psc, new RowMapperResultSetExtractor<T>(rowMapper));
	}

	public <T> List<T> query(String sql, PreparedStatementSetter pss, RowMapper<T> rowMapper) throws DataAccessException {
		return query(sql, pss, new RowMapperResultSetExtractor<T>(rowMapper));
	}

	public <T> List<T> query(String sql, Object[] args, int[] argTypes, RowMapper<T> rowMapper) throws DataAccessException {
		return query(sql, args, argTypes, new RowMapperResultSetExtractor<T>(rowMapper));
	}

	public <T> List<T> query(String sql, Object[] args, RowMapper<T> rowMapper) throws DataAccessException {
		return query(sql, args, new RowMapperResultSetExtractor<T>(rowMapper));
	}

	public <T> List<T> query(String sql, RowMapper<T> rowMapper, Object... args) throws DataAccessException {
		return query(sql, args, new RowMapperResultSetExtractor<T>(rowMapper));
	}

	public <T> T queryForObject(String sql, Object[] args, int[] argTypes, RowMapper<T> rowMapper)
			throws DataAccessException {

		List<T> results = query(sql, args, argTypes, new RowMapperResultSetExtractor<T>(rowMapper, 1));
		return DataAccessUtils.requiredSingleResult(results);
	}

	public <T> T queryForObject(String sql, Object[] args, RowMapper<T> rowMapper) throws DataAccessException {
		List<T> results = query(sql, args, new RowMapperResultSetExtractor<T>(rowMapper, 1));
		return DataAccessUtils.requiredSingleResult(results);
	}

	public <T> T queryForObject(String sql, RowMapper<T> rowMapper, Object... args) throws DataAccessException {
		List<T> results = query(sql, args, new RowMapperResultSetExtractor<T>(rowMapper, 1));
		return DataAccessUtils.requiredSingleResult(results);
	}

	public <T> T queryForObject(String sql, Object[] args, int[] argTypes, Class<T> requiredType)
			throws DataAccessException {

		return queryForObject(sql, args, argTypes, getSingleColumnRowMapper(requiredType));
	}

	public <T> T queryForObject(String sql, Object[] args, Class<T> requiredType) throws DataAccessException {
		return queryForObject(sql, args, getSingleColumnRowMapper(requiredType));
	}

	public <T> T queryForObject(String sql, Class<T> requiredType, Object... args) throws DataAccessException {
		return queryForObject(sql, args, getSingleColumnRowMapper(requiredType));
	}

	public Map<String, Object> queryForMap(String sql, Object[] args, int[] argTypes) throws DataAccessException {
		return queryForObject(sql, args, argTypes, getColumnMapRowMapper());
	}

	public Map<String, Object> queryForMap(String sql, Object... args) throws DataAccessException {
		return queryForObject(sql, args, getColumnMapRowMapper());
	}

	@Deprecated
	public long queryForLong(String sql, Object[] args, int[] argTypes) throws DataAccessException {
		Number number = queryForObject(sql, args, argTypes, Long.class);
		return (number != null ? number.longValue() : 0);
	}

	@Deprecated
	public long queryForLong(String sql, Object... args) throws DataAccessException {
		Number number = queryForObject(sql, args, Long.class);
		return (number != null ? number.longValue() : 0);
	}

	@Deprecated
	public int queryForInt(String sql, Object[] args, int[] argTypes) throws DataAccessException {
		Number number = queryForObject(sql, args, argTypes, Integer.class);
		return (number != null ? number.intValue() : 0);
	}

	@Deprecated
	public int queryForInt(String sql, Object... args) throws DataAccessException {
		Number number = queryForObject(sql, args, Integer.class);
		return (number != null ? number.intValue() : 0);
	}

	public <T> List<T> queryForList(String sql, Object[] args, int[] argTypes, Class<T> elementType) throws DataAccessException {
		return query(sql, args, argTypes, getSingleColumnRowMapper(elementType));
	}

	public <T> List<T> queryForList(String sql, Object[] args, Class<T> elementType) throws DataAccessException {
		return query(sql, args, getSingleColumnRowMapper(elementType));
	}

	public <T> List<T> queryForList(String sql, Class<T> elementType, Object... args) throws DataAccessException {
		return query(sql, args, getSingleColumnRowMapper(elementType));
	}

	public List<Map<String, Object>> queryForList(String sql, Object[] args, int[] argTypes) throws DataAccessException {
		return query(sql, args, argTypes, getColumnMapRowMapper());
	}

	public List<Map<String, Object>> queryForList(String sql, Object... args) throws DataAccessException {
		return query(sql, args, getColumnMapRowMapper());
	}

	public SqlRowSet queryForRowSet(String sql, Object[] args, int[] argTypes) throws DataAccessException {
		return query(sql, args, argTypes, new SqlRowSetResultSetExtractor());
	}

	public SqlRowSet queryForRowSet(String sql, Object... args) throws DataAccessException {
		return query(sql, args, new SqlRowSetResultSetExtractor());
	}

	protected int update(final PreparedStatementCreator psc, final PreparedStatementSetter pss)
			throws DataAccessException {

		logger.debug("Executing prepared SQL update");
		return execute(psc, new PreparedStatementCallback<Integer>() {
			public Integer doInPreparedStatement(PreparedStatement ps) throws SQLException {
				try {
					if (pss != null) {
						pss.setValues(ps);
					}
					int rows = ps.executeUpdate();
					if (logger.isDebugEnabled()) {
						logger.debug("SQL update affected " + rows + " rows");
					}
					return rows;
				}
				finally {
					if (pss instanceof ParameterDisposer) {
						((ParameterDisposer) pss).cleanupParameters();
					}
				}
			}
		});
	}

	public int update(PreparedStatementCreator psc) throws DataAccessException {
		return update(psc, (PreparedStatementSetter) null);
	}

	public int update(final PreparedStatementCreator psc, final KeyHolder generatedKeyHolder)
			throws DataAccessException {

		Assert.notNull(generatedKeyHolder, "KeyHolder must not be null");
		logger.debug("Executing SQL update and returning generated keys");

		return execute(psc, new PreparedStatementCallback<Integer>() {
			public Integer doInPreparedStatement(PreparedStatement ps) throws SQLException {
				int rows = ps.executeUpdate();
				List<Map<String, Object>> generatedKeys = generatedKeyHolder.getKeyList();
				generatedKeys.clear();
				ResultSet keys = ps.getGeneratedKeys();
				if (keys != null) {
					try {
						RowMapperResultSetExtractor<Map<String, Object>> rse =
								new RowMapperResultSetExtractor<Map<String, Object>>(getColumnMapRowMapper(), 1);
						generatedKeys.addAll(rse.extractData(keys));
					}
					finally {
						JdbcUtils.closeResultSet(keys);
					}
				}
				if (logger.isDebugEnabled()) {
					logger.debug("SQL update affected " + rows + " rows and returned " + generatedKeys.size() + " keys");
				}
				return rows;
			}
		});
	}

	public int update(String sql, PreparedStatementSetter pss) throws DataAccessException {
		return update(new SimplePreparedStatementCreator(sql), pss);
	}

	public int update(String sql, Object[] args, int[] argTypes) throws DataAccessException {
		return update(sql, newArgTypePreparedStatementSetter(args, argTypes));
	}

	public int update(String sql, Object... args) throws DataAccessException {
		return update(sql, newArgPreparedStatementSetter(args));
	}

	public int[] batchUpdate(String sql, final BatchPreparedStatementSetter pss) throws DataAccessException {
		if (logger.isDebugEnabled()) {
			logger.debug("Executing SQL batch update [" + sql + "]");
		}

		return execute(sql, new PreparedStatementCallback<int[]>() {
			public int[] doInPreparedStatement(PreparedStatement ps) throws SQLException {
				try {
					int batchSize = pss.getBatchSize();
					InterruptibleBatchPreparedStatementSetter ipss =
							(pss instanceof InterruptibleBatchPreparedStatementSetter ?
							(InterruptibleBatchPreparedStatementSetter) pss : null);
					if (JdbcUtils.supportsBatchUpdates(ps.getConnection())) {
						for (int i = 0; i < batchSize; i++) {
							pss.setValues(ps, i);
							if (ipss != null && ipss.isBatchExhausted(i)) {
								break;
							}
							ps.addBatch();
						}
						return ps.executeBatch();
					}
					else {
						List<Integer> rowsAffected = new ArrayList<Integer>();
						for (int i = 0; i < batchSize; i++) {
							pss.setValues(ps, i);
							if (ipss != null && ipss.isBatchExhausted(i)) {
								break;
							}
							rowsAffected.add(ps.executeUpdate());
						}
						int[] rowsAffectedArray = new int[rowsAffected.size()];
						for (int i = 0; i < rowsAffectedArray.length; i++) {
							rowsAffectedArray[i] = rowsAffected.get(i);
						}
						return rowsAffectedArray;
					}
				}
				finally {
					if (pss instanceof ParameterDisposer) {
						((ParameterDisposer) pss).cleanupParameters();
					}
				}
			}
		});
	}

	public int[] batchUpdate(String sql, List<Object[]> batchArgs) {
		return batchUpdate(sql, batchArgs, new int[0]);
	}

	public int[] batchUpdate(String sql, List<Object[]> batchArgs, int[] argTypes) {
		return BatchUpdateUtils.executeBatchUpdate(sql, batchArgs, argTypes, this);
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.jdbc.core.JdbcOperations#batchUpdate(java.lang.String, java.util.Collection, int, org.springframework.jdbc.core.ParameterizedPreparedStatementSetter)
	 *
	 * Contribution by Nicolas Fabre
	 */
	public <T> int[][] batchUpdate(String sql, final Collection<T> batchArgs, final int batchSize, final ParameterizedPreparedStatementSetter<T> pss) {
		if (logger.isDebugEnabled()) {
			logger.debug("Executing SQL batch update [" + sql + "] with a batch size of " + batchSize);
		}
		return execute(sql, new PreparedStatementCallback<int[][]>() {
			public int[][] doInPreparedStatement(PreparedStatement ps) throws SQLException {
				List<int[]> rowsAffected = new ArrayList<int[]>();
				try {
					boolean batchSupported = true;
					if (!JdbcUtils.supportsBatchUpdates(ps.getConnection())) {
						batchSupported = false;
						logger.warn("JDBC Driver does not support Batch updates; resorting to single statement execution");
					}
					int n = 0;
					for (T obj : batchArgs) {
						pss.setValues(ps, obj);
						n++;
						if (batchSupported) {
							ps.addBatch();
							if (n % batchSize == 0 || n == batchArgs.size()) {
								if (logger.isDebugEnabled()) {
									int batchIdx = (n % batchSize == 0) ? n / batchSize : (n / batchSize) + 1;
									int items = n - ((n % batchSize == 0) ? n / batchSize - 1 : (n / batchSize)) * batchSize;
									logger.debug("Sending SQL batch update #" + batchIdx + " with " + items + " items");
								}
								rowsAffected.add(ps.executeBatch());
							}
						}
						else {
							int i = ps.executeUpdate();
							rowsAffected.add(new int[] {i});
						}
					}
					int[][] result = new int[rowsAffected.size()][];
					for (int i = 0; i < result.length; i++) {
						result[i] = rowsAffected.get(i);
					}
					return result;
				} finally {
					if (pss instanceof ParameterDisposer) {
						((ParameterDisposer) pss).cleanupParameters();
					}
				}
			}
		});
	}

	//-------------------------------------------------------------------------
	// Methods dealing with callable statements
	//-------------------------------------------------------------------------

	public <T> T execute(CallableStatementCreator csc, CallableStatementCallback<T> action)
			throws DataAccessException {

		Assert.notNull(csc, "CallableStatementCreator must not be null");
		Assert.notNull(action, "Callback object must not be null");
		if (logger.isDebugEnabled()) {
			String sql = getSql(csc);
			logger.debug("Calling stored procedure" + (sql != null ? " [" + sql  + "]" : ""));
		}

		Connection con = DataSourceUtils.getConnection(getDataSource());
		CallableStatement cs = null;
		try {
			Connection conToUse = con;
			if (this.nativeJdbcExtractor != null) {
				conToUse = this.nativeJdbcExtractor.getNativeConnection(con);
			}
			cs = csc.createCallableStatement(conToUse);
			applyStatementSettings(cs);
			CallableStatement csToUse = cs;
			if (this.nativeJdbcExtractor != null) {
				csToUse = this.nativeJdbcExtractor.getNativeCallableStatement(cs);
			}
			T result = action.doInCallableStatement(csToUse);
			handleWarnings(cs);
			return result;
		}
		catch (SQLException ex) {
			// Release Connection early, to avoid potential connection pool deadlock
			// in the case when the exception translator hasn't been initialized yet.
			if (csc instanceof ParameterDisposer) {
				((ParameterDisposer) csc).cleanupParameters();
			}
			String sql = getSql(csc);
			csc = null;
			JdbcUtils.closeStatement(cs);
			cs = null;
			DataSourceUtils.releaseConnection(con, getDataSource());
			con = null;
			throw getExceptionTranslator().translate("CallableStatementCallback", sql, ex);
		}
		finally {
			if (csc instanceof ParameterDisposer) {
				((ParameterDisposer) csc).cleanupParameters();
			}
			JdbcUtils.closeStatement(cs);
			DataSourceUtils.releaseConnection(con, getDataSource());
		}
	}

	public <T> T execute(String callString, CallableStatementCallback<T> action) throws DataAccessException {
		return execute(new SimpleCallableStatementCreator(callString), action);
	}

	public Map<String, Object> call(CallableStatementCreator csc, List<SqlParameter> declaredParameters)
			throws DataAccessException {

		final List<SqlParameter> updateCountParameters = new ArrayList<SqlParameter>();
		final List<SqlParameter> resultSetParameters = new ArrayList<SqlParameter>();
		final List<SqlParameter> callParameters = new ArrayList<SqlParameter>();
		for (SqlParameter parameter : declaredParameters) {
			if (parameter.isResultsParameter()) {
				if (parameter instanceof SqlReturnResultSet) {
					resultSetParameters.add(parameter);
				}
				else {
					updateCountParameters.add(parameter);
				}
			}
			else {
				callParameters.add(parameter);
			}
		}
		return execute(csc, new CallableStatementCallback<Map<String, Object>>() {
			public Map<String, Object> doInCallableStatement(CallableStatement cs) throws SQLException {
				boolean retVal = cs.execute();
				int updateCount = cs.getUpdateCount();
				if (logger.isDebugEnabled()) {
					logger.debug("CallableStatement.execute() returned '" + retVal + "'");
					logger.debug("CallableStatement.getUpdateCount() returned " + updateCount);
				}
				Map<String, Object> returnedResults = createResultsMap();
				if (retVal || updateCount != -1) {
					returnedResults.putAll(extractReturnedResults(cs, updateCountParameters, resultSetParameters, updateCount));
				}
				returnedResults.putAll(extractOutputParameters(cs, callParameters));
				return returnedResults;
			}
		});
	}

	/**
	 * Extract returned ResultSets from the completed stored procedure.
	 * @param cs JDBC wrapper for the stored procedure
	 * @param updateCountParameters Parameter list of declared update count parameters for the stored procedure
	 * @param resultSetParameters Parameter list of declared resultSet parameters for the stored procedure
	 * @return Map that contains returned results
	 */
	@SuppressWarnings("rawtypes")
	protected Map<String, Object> extractReturnedResults(
			CallableStatement cs, List updateCountParameters, List resultSetParameters, int updateCount)
			throws SQLException {

		Map<String, Object> returnedResults = new HashMap<String, Object>();
		int rsIndex = 0;
		int updateIndex = 0;
		boolean moreResults;
		if (!skipResultsProcessing) {
			do {
				if (updateCount == -1) {
					if (resultSetParameters != null && resultSetParameters.size() > rsIndex) {
						SqlReturnResultSet declaredRsParam = (SqlReturnResultSet)resultSetParameters.get(rsIndex);
						returnedResults.putAll(processResultSet(cs.getResultSet(), declaredRsParam));
						rsIndex++;
					}
					else {
						if (!skipUndeclaredResults) {
							String rsName = RETURN_RESULT_SET_PREFIX + (rsIndex + 1);
							SqlReturnResultSet undeclaredRsParam = new SqlReturnResultSet(rsName, new ColumnMapRowMapper());
							logger.info("Added default SqlReturnResultSet parameter named " + rsName);
							returnedResults.putAll(processResultSet(cs.getResultSet(), undeclaredRsParam));
							rsIndex++;
						}
					}
				}
				else {
					if (updateCountParameters != null && updateCountParameters.size() > updateIndex) {
						SqlReturnUpdateCount ucParam = (SqlReturnUpdateCount)updateCountParameters.get(updateIndex);
						String declaredUcName = ucParam.getName();
						returnedResults.put(declaredUcName, updateCount);
						updateIndex++;
					}
					else {
						if (!skipUndeclaredResults) {
							String undeclaredUcName = RETURN_UPDATE_COUNT_PREFIX + (updateIndex + 1);
							logger.info("Added default SqlReturnUpdateCount parameter named " + undeclaredUcName);
							returnedResults.put(undeclaredUcName, updateCount);
							updateIndex++;
						}
					}
				}
				moreResults = cs.getMoreResults();
				updateCount = cs.getUpdateCount();
				if (logger.isDebugEnabled()) {
					logger.debug("CallableStatement.getUpdateCount() returned " + updateCount);
				}
			}
			while (moreResults || updateCount != -1);
		}
		return returnedResults;
	}

	/**
	 * Extract output parameters from the completed stored procedure.
	 * @param cs JDBC wrapper for the stored procedure
	 * @param parameters parameter list for the stored procedure
	 * @return Map that contains returned results
	 */
	protected Map<String, Object> extractOutputParameters(CallableStatement cs, List<SqlParameter> parameters)
			throws SQLException {

		Map<String, Object> returnedResults = new HashMap<String, Object>();
		int sqlColIndex = 1;
		for (SqlParameter param : parameters) {
			if (param instanceof SqlOutParameter) {
				SqlOutParameter outParam = (SqlOutParameter) param;
				if (outParam.isReturnTypeSupported()) {
					Object out = outParam.getSqlReturnType().getTypeValue(
							cs, sqlColIndex, outParam.getSqlType(), outParam.getTypeName());
					returnedResults.put(outParam.getName(), out);
				}
				else {
					Object out = cs.getObject(sqlColIndex);
					if (out instanceof ResultSet) {
						if (outParam.isResultSetSupported()) {
							returnedResults.putAll(processResultSet((ResultSet) out, outParam));
						}
						else {
							String rsName = outParam.getName();
							SqlReturnResultSet rsParam = new SqlReturnResultSet(rsName, new ColumnMapRowMapper());
							returnedResults.putAll(processResultSet(cs.getResultSet(), rsParam));
							logger.info("Added default SqlReturnResultSet parameter named " + rsName);
						}
					}
					else {
						returnedResults.put(outParam.getName(), out);
					}
				}
			}
			if (!(param.isResultsParameter())) {
				sqlColIndex++;
			}
		}
		return returnedResults;
	}

	/**
	 * Process the given ResultSet from a stored procedure.
	 * @param rs the ResultSet to process
	 * @param param the corresponding stored procedure parameter
	 * @return Map that contains returned results
	 */
	@SuppressWarnings({ "unchecked", "rawtypes" })
	protected Map<String, Object> processResultSet(ResultSet rs, ResultSetSupportingSqlParameter param) throws SQLException {
		if (rs == null) {
			return Collections.emptyMap();
		}
		Map<String, Object> returnedResults = new HashMap<String, Object>();
		try {
			ResultSet rsToUse = rs;
			if (this.nativeJdbcExtractor != null) {
				rsToUse = this.nativeJdbcExtractor.getNativeResultSet(rs);
			}
			if (param.getRowMapper() != null) {
				RowMapper rowMapper = param.getRowMapper();
				Object result = (new RowMapperResultSetExtractor(rowMapper)).extractData(rsToUse);
				returnedResults.put(param.getName(), result);
			}
			else if (param.getRowCallbackHandler() != null) {
				RowCallbackHandler rch = param.getRowCallbackHandler();
				(new RowCallbackHandlerResultSetExtractor(rch)).extractData(rsToUse);
				returnedResults.put(param.getName(), "ResultSet returned from stored procedure was processed");
			}
			else if (param.getResultSetExtractor() != null) {
				Object result = param.getResultSetExtractor().extractData(rsToUse);
				returnedResults.put(param.getName(), result);
			}
		}
		finally {
			JdbcUtils.closeResultSet(rs);
		}
		return returnedResults;
	}


	//-------------------------------------------------------------------------
	// Implementation hooks and helper methods
	//-------------------------------------------------------------------------

	/**
	 * Create a new RowMapper for reading columns as key-value pairs.
	 * @return the RowMapper to use
	 * @see ColumnMapRowMapper
	 */
	protected RowMapper<Map<String, Object>> getColumnMapRowMapper() {
		return new ColumnMapRowMapper();
	}

	/**
	 * Create a new RowMapper for reading result objects from a single column.
	 * @param requiredType the type that each result object is expected to match
	 * @return the RowMapper to use
	 * @see SingleColumnRowMapper
	 */
	protected <T> RowMapper<T> getSingleColumnRowMapper(Class<T> requiredType) {
		return new SingleColumnRowMapper<T>(requiredType);
	}

	/**
	 * Create a Map instance to be used as results map.
	 * <p>If "isResultsMapCaseInsensitive" has been set to true,
	 * a linked case-insensitive Map will be created.
	 * @return the results Map instance
	 * @see #setResultsMapCaseInsensitive
	 */
	protected Map<String, Object> createResultsMap() {
		if (isResultsMapCaseInsensitive()) {
			return new LinkedCaseInsensitiveMap<Object>();
		}
		else {
			return new LinkedHashMap<String, Object>();
		}
	}

	/**
	 * Prepare the given JDBC Statement (or PreparedStatement or CallableStatement),
	 * applying statement settings such as fetch size, max rows, and query timeout.
	 * @param stmt the JDBC Statement to prepare
	 * @throws SQLException if thrown by JDBC API
	 * @see #setFetchSize
	 * @see #setMaxRows
	 * @see #setQueryTimeout
	 * @see org.springframework.jdbc.datasource.DataSourceUtils#applyTransactionTimeout
	 */
	protected void applyStatementSettings(Statement stmt) throws SQLException {
		int fetchSize = getFetchSize();
		if (fetchSize > 0) {
			stmt.setFetchSize(fetchSize);
		}
		int maxRows = getMaxRows();
		if (maxRows > 0) {
			stmt.setMaxRows(maxRows);
		}
		DataSourceUtils.applyTimeout(stmt, getDataSource(), getQueryTimeout());
	}

	/**
	 * Create a new ArgPreparedStatementSetter using the args passed in. This method allows the
	 * creation to be overridden by sub-classes.
	 * @param args object array with arguments
	 * @return the new PreparedStatementSetter
	 */
	protected PreparedStatementSetter newArgPreparedStatementSetter(Object[] args) {
		return new ArgPreparedStatementSetter(args);
	}

	/**
	 * Create a new ArgTypePreparedStatementSetter using the args and argTypes passed in.
	 * This method allows the creation to be overridden by sub-classes.
	 * @param args object array with arguments
	 * @param argTypes int array of SQLTypes for arguments
	 * @return the new PreparedStatementSetter
	 */
	protected PreparedStatementSetter newArgTypePreparedStatementSetter(Object[] args, int[] argTypes) {
		return new ArgTypePreparedStatementSetter(args, argTypes);
	}

	/**
	 * Throw an SQLWarningException if we're not ignoring warnings,
	 * else log the warnings (at debug level).
	 * @param stmt the current JDBC statement
	 * @throws SQLWarningException if not ignoring warnings
	 * @see org.springframework.jdbc.SQLWarningException
	 */
	protected void handleWarnings(Statement stmt) throws SQLException {
		if (isIgnoreWarnings()) {
			if (logger.isDebugEnabled()) {
				SQLWarning warningToLog = stmt.getWarnings();
				while (warningToLog != null) {
					logger.debug("SQLWarning ignored: SQL state '" + warningToLog.getSQLState() + "', error code '" +
							warningToLog.getErrorCode() + "', message [" + warningToLog.getMessage() + "]");
					warningToLog = warningToLog.getNextWarning();
				}
			}
		}
		else {
			handleWarnings(stmt.getWarnings());
		}
	}

	/**
	 * Throw an SQLWarningException if encountering an actual warning.
	 * @param warning the warnings object from the current statement.
	 * May be {@code null}, in which case this method does nothing.
	 * @throws SQLWarningException in case of an actual warning to be raised
	 */
	protected void handleWarnings(SQLWarning warning) throws SQLWarningException {
		if (warning != null) {
			throw new SQLWarningException("Warning not ignored", warning);
		}
	}

	/**
	 * Determine SQL from potential provider object.
	 * @param sqlProvider object that's potentially a SqlProvider
	 * @return the SQL string, or {@code null}
	 * @see SqlProvider
	 */
	private static String getSql(Object sqlProvider) {
		if (sqlProvider instanceof SqlProvider) {
			return ((SqlProvider) sqlProvider).getSql();
		}
		else {
			return null;
		}
	}


	/**
	 * Invocation handler that suppresses close calls on JDBC Connections.
	 * Also prepares returned Statement (Prepared/CallbackStatement) objects.
	 * @see java.sql.Connection#close()
	 */
	private class CloseSuppressingInvocationHandler implements InvocationHandler {

		private final Connection target;

		public CloseSuppressingInvocationHandler(Connection target) {
			this.target = target;
		}

		@SuppressWarnings("rawtypes")
		public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
			// Invocation on ConnectionProxy interface coming in...

			if (method.getName().equals("equals")) {
				// Only consider equal when proxies are identical.
				return (proxy == args[0]);
			}
			else if (method.getName().equals("hashCode")) {
				// Use hashCode of PersistenceManager proxy.
				return System.identityHashCode(proxy);
			}
			else if (method.getName().equals("unwrap")) {
				if (((Class) args[0]).isInstance(proxy)) {
					return proxy;
				}
			}
			else if (method.getName().equals("isWrapperFor")) {
				if (((Class) args[0]).isInstance(proxy)) {
					return true;
				}
			}
			else if (method.getName().equals("close")) {
				// Handle close method: suppress, not valid.
				return null;
			}
			else if (method.getName().equals("isClosed")) {
				return false;
			}
			else if (method.getName().equals("getTargetConnection")) {
				// Handle getTargetConnection method: return underlying Connection.
				return this.target;
			}

			// Invoke method on target Connection.
			try {
				Object retVal = method.invoke(this.target, args);

				// If return value is a JDBC Statement, apply statement settings
				// (fetch size, max rows, transaction timeout).
				if (retVal instanceof Statement) {
					applyStatementSettings(((Statement) retVal));
				}

				return retVal;
			}
			catch (InvocationTargetException ex) {
				throw ex.getTargetException();
			}
		}
	}


	/**
	 * Simple adapter for PreparedStatementCreator, allowing to use a plain SQL statement.
	 */
	private static class SimplePreparedStatementCreator implements PreparedStatementCreator, SqlProvider {

		private final String sql;

		public SimplePreparedStatementCreator(String sql) {
			Assert.notNull(sql, "SQL must not be null");
			this.sql = sql;
		}

		public PreparedStatement createPreparedStatement(Connection con) throws SQLException {
			return con.prepareStatement(this.sql);
		}

		public String getSql() {
			return this.sql;
		}
	}


	/**
	 * Simple adapter for CallableStatementCreator, allowing to use a plain SQL statement.
	 */
	private static class SimpleCallableStatementCreator implements CallableStatementCreator, SqlProvider {

		private final String callString;

		public SimpleCallableStatementCreator(String callString) {
			Assert.notNull(callString, "Call string must not be null");
			this.callString = callString;
		}

		public CallableStatement createCallableStatement(Connection con) throws SQLException {
			return con.prepareCall(this.callString);
		}

		public String getSql() {
			return this.callString;
		}
	}


	/**
	 * Adapter to enable use of a RowCallbackHandler inside a ResultSetExtractor.
	 * <p>Uses a regular ResultSet, so we have to be careful when using it:
	 * We don't use it for navigating since this could lead to unpredictable consequences.
	 */
	private static class RowCallbackHandlerResultSetExtractor implements ResultSetExtractor<Object> {

		private final RowCallbackHandler rch;

		public RowCallbackHandlerResultSetExtractor(RowCallbackHandler rch) {
			this.rch = rch;
		}

		public Object extractData(ResultSet rs) throws SQLException {
			while (rs.next()) {
				this.rch.processRow(rs);
			}
			return null;
		}
	}

}
