/*
 * 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
 *
 *      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.support.rowset;

import java.math.BigDecimal;
import java.sql.Date;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.Calendar;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.springframework.jdbc.InvalidResultSetAccessException;

The default implementation of Spring's SqlRowSet interface, wrapping a ResultSet, catching any SQLExceptions and translating them to a corresponding Spring InvalidResultSetAccessException. 
The passed-in ResultSet should already be disconnected if the SqlRowSet is supposed to be usable in a disconnected fashion. This means that you will usually pass in a javax.sql.rowset.CachedRowSet, which implements the ResultSet interface. 
Note: Since JDBC 4.0, it has been clarified that any methods using a String to identify the column should be using the column label. The column label is assigned using the ALIAS keyword in the SQL query string. When the query doesn't use an ALIAS, the default label is the column name. Most JDBC ResultSet implementations follow this new pattern but there are exceptions such as the com.sun.rowset.CachedRowSetImpl class which only uses the column name, ignoring any column labels. As of Spring 3.0.5, ResultSetWrappingSqlRowSet will translate column labels to the correct column index to provide better support for the com.sun.rowset.CachedRowSetImpl which is the default implementation used by JdbcTemplate when working with RowSets. 
Note: This class implements the java.io.Serializable marker interface through the SqlRowSet interface, but is only actually serializable if the disconnected ResultSet/RowSet contained in it is serializable. Most CachedRowSet implementations are actually serializable, so this should usually work out. 
Author:
Thomas Risberg, Juergen Hoeller
See Also:
ResultSet
CachedRowSet
JdbcTemplate.queryForRowSet
Since:
1.2/**
 * The default implementation of Spring's {@link SqlRowSet} interface, wrapping a
 * {@link java.sql.ResultSet}, catching any {@link SQLException SQLExceptions} and
 * translating them to a corresponding Spring {@link InvalidResultSetAccessException}.
 *
 * <p>The passed-in ResultSet should already be disconnected if the SqlRowSet is supposed
 * to be usable in a disconnected fashion. This means that you will usually pass in a
 * {@code javax.sql.rowset.CachedRowSet}, which implements the ResultSet interface.
 *
 * <p>Note: Since JDBC 4.0, it has been clarified that any methods using a String to identify
 * the column should be using the column label. The column label is assigned using the ALIAS
 * keyword in the SQL query string. When the query doesn't use an ALIAS, the default label is
 * the column name. Most JDBC ResultSet implementations follow this new pattern but there are
 * exceptions such as the {@code com.sun.rowset.CachedRowSetImpl} class which only uses
 * the column name, ignoring any column labels. As of Spring 3.0.5, ResultSetWrappingSqlRowSet
 * will translate column labels to the correct column index to provide better support for the
 * {@code com.sun.rowset.CachedRowSetImpl} which is the default implementation used by
 * {@link org.springframework.jdbc.core.JdbcTemplate} when working with RowSets.
 *
 * <p>Note: This class implements the {@code java.io.Serializable} marker interface
 * through the SqlRowSet interface, but is only actually serializable if the disconnected
 * ResultSet/RowSet contained in it is serializable. Most CachedRowSet implementations
 * are actually serializable, so this should usually work out.
 *
 * @author Thomas Risberg
 * @author Juergen Hoeller
 * @since 1.2
 * @see java.sql.ResultSet
 * @see javax.sql.rowset.CachedRowSet
 * @see org.springframework.jdbc.core.JdbcTemplate#queryForRowSet
 */
public class ResultSetWrappingSqlRowSet implements SqlRowSet {

	
use serialVersionUID from Spring 1.2 for interoperability. /** use serialVersionUID from Spring 1.2 for interoperability. */
	private static final long serialVersionUID = -4688694393146734764L;


	private final ResultSet resultSet;

	private final SqlRowSetMetaData rowSetMetaData;

	private final Map<String, Integer> columnLabelMap;


	
Create a new ResultSetWrappingSqlRowSet for the given ResultSet.
Params:
resultSet – a disconnected ResultSet to wrap (usually a javax.sql.rowset.CachedRowSet)
Throws:
InvalidResultSetAccessException – if extracting
the ResultSetMetaData failed
See Also:
CachedRowSet
ResultSet.getMetaData
ResultSetWrappingSqlRowSetMetaData/**
	 * Create a new ResultSetWrappingSqlRowSet for the given ResultSet.
	 * @param resultSet a disconnected ResultSet to wrap
	 * (usually a {@code javax.sql.rowset.CachedRowSet})
	 * @throws InvalidResultSetAccessException if extracting
	 * the ResultSetMetaData failed
	 * @see javax.sql.rowset.CachedRowSet
	 * @see java.sql.ResultSet#getMetaData
	 * @see ResultSetWrappingSqlRowSetMetaData
	 */
	public ResultSetWrappingSqlRowSet(ResultSet resultSet) throws InvalidResultSetAccessException {
		this.resultSet = resultSet;
		try {
			this.rowSetMetaData = new ResultSetWrappingSqlRowSetMetaData(resultSet.getMetaData());
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
		try {
			ResultSetMetaData rsmd = resultSet.getMetaData();
			if (rsmd != null) {
				int columnCount = rsmd.getColumnCount();
				this.columnLabelMap = new HashMap<>(columnCount);
				for (int i = 1; i <= columnCount; i++) {
					String key = rsmd.getColumnLabel(i);
					// Make sure to preserve first matching column for any given name,
					// as defined in ResultSet's type-level javadoc (lines 81 to 83).
					if (!this.columnLabelMap.containsKey(key)) {
						this.columnLabelMap.put(key, i);
					}
				}
			}
			else {
				this.columnLabelMap = Collections.emptyMap();
			}
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}

	}


	
Return the underlying ResultSet (usually a javax.sql.rowset.CachedRowSet). 
See Also:
CachedRowSet/**
	 * Return the underlying ResultSet
	 * (usually a {@code javax.sql.rowset.CachedRowSet}).
	 * @see javax.sql.rowset.CachedRowSet
	 */
	public final ResultSet getResultSet() {
		return this.resultSet;
	}

	
See Also:
getCatalogName.getCatalogName(int)/**
	 * @see java.sql.ResultSetMetaData#getCatalogName(int)
	 */
	@Override
	public final SqlRowSetMetaData getMetaData() {
		return this.rowSetMetaData;
	}

	
See Also:
findColumn.findColumn(String)/**
	 * @see java.sql.ResultSet#findColumn(String)
	 */
	@Override
	public int findColumn(String columnLabel) throws InvalidResultSetAccessException {
		Integer columnIndex = this.columnLabelMap.get(columnLabel);
		if (columnIndex != null) {
			return columnIndex;
		}
		else {
			try {
				return this.resultSet.findColumn(columnLabel);
			}
			catch (SQLException se) {
				throw new InvalidResultSetAccessException(se);
			}
		}
	}


	// RowSet methods for extracting data values

	
See Also:
getBigDecimal.getBigDecimal(int)/**
	 * @see java.sql.ResultSet#getBigDecimal(int)
	 */
	@Override
	public BigDecimal getBigDecimal(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getBigDecimal(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getBigDecimal.getBigDecimal(String)/**
	 * @see java.sql.ResultSet#getBigDecimal(String)
	 */
	@Override
	public BigDecimal getBigDecimal(String columnLabel) throws InvalidResultSetAccessException {
		return getBigDecimal(findColumn(columnLabel));
	}

	
See Also:
getBoolean.getBoolean(int)/**
	 * @see java.sql.ResultSet#getBoolean(int)
	 */
	@Override
	public boolean getBoolean(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getBoolean(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getBoolean.getBoolean(String)/**
	 * @see java.sql.ResultSet#getBoolean(String)
	 */
	@Override
	public boolean getBoolean(String columnLabel) throws InvalidResultSetAccessException {
		return getBoolean(findColumn(columnLabel));
	}

	
See Also:
getByte.getByte(int)/**
	 * @see java.sql.ResultSet#getByte(int)
	 */
	@Override
	public byte getByte(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getByte(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getByte.getByte(String)/**
	 * @see java.sql.ResultSet#getByte(String)
	 */
	@Override
	public byte getByte(String columnLabel) throws InvalidResultSetAccessException {
		return getByte(findColumn(columnLabel));
	}

	
See Also:
getDate.getDate(int)/**
	 * @see java.sql.ResultSet#getDate(int)
	 */
	@Override
	public Date getDate(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getDate(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getDate.getDate(String)/**
	 * @see java.sql.ResultSet#getDate(String)
	 */
	@Override
	public Date getDate(String columnLabel) throws InvalidResultSetAccessException {
		return getDate(findColumn(columnLabel));
	}

	
See Also:
getDate.getDate(int, Calendar)/**
	 * @see java.sql.ResultSet#getDate(int, Calendar)
	 */
	@Override
	public Date getDate(int columnIndex, Calendar cal) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getDate(columnIndex, cal);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getDate.getDate(String, Calendar)/**
	 * @see java.sql.ResultSet#getDate(String, Calendar)
	 */
	@Override
	public Date getDate(String columnLabel, Calendar cal) throws InvalidResultSetAccessException {
		return getDate(findColumn(columnLabel), cal);
	}

	
See Also:
getDouble.getDouble(int)/**
	 * @see java.sql.ResultSet#getDouble(int)
	 */
	@Override
	public double getDouble(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getDouble(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getDouble.getDouble(String)/**
	 * @see java.sql.ResultSet#getDouble(String)
	 */
	@Override
	public double getDouble(String columnLabel) throws InvalidResultSetAccessException {
		return getDouble(findColumn(columnLabel));
	}

	
See Also:
getFloat.getFloat(int)/**
	 * @see java.sql.ResultSet#getFloat(int)
	 */
	@Override
	public float getFloat(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getFloat(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getFloat.getFloat(String)/**
	 * @see java.sql.ResultSet#getFloat(String)
	 */
	@Override
	public float getFloat(String columnLabel) throws InvalidResultSetAccessException {
		return getFloat(findColumn(columnLabel));
	}

	
See Also:
getInt.getInt(int)/**
	 * @see java.sql.ResultSet#getInt(int)
	 */
	@Override
	public int getInt(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getInt(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getInt.getInt(String)/**
	 * @see java.sql.ResultSet#getInt(String)
	 */
	@Override
	public int getInt(String columnLabel) throws InvalidResultSetAccessException {
		return getInt(findColumn(columnLabel));
	}

	
See Also:
getLong.getLong(int)/**
	 * @see java.sql.ResultSet#getLong(int)
	 */
	@Override
	public long getLong(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getLong(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getLong.getLong(String)/**
	 * @see java.sql.ResultSet#getLong(String)
	 */
	@Override
	public long getLong(String columnLabel) throws InvalidResultSetAccessException {
		return getLong(findColumn(columnLabel));
	}

	
See Also:
getNString.getNString(int)/**
	 * @see java.sql.ResultSet#getNString(int)
	 */
	@Override
	public String getNString(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getNString(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getNString.getNString(String)/**
	 * @see java.sql.ResultSet#getNString(String)
	 */
	@Override
	public String getNString(String columnLabel) throws InvalidResultSetAccessException {
		return getNString(findColumn(columnLabel));
	}

	
See Also:
getObject.getObject(int)/**
	 * @see java.sql.ResultSet#getObject(int)
	 */
	@Override
	public Object getObject(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getObject(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getObject.getObject(String)/**
	 * @see java.sql.ResultSet#getObject(String)
	 */
	@Override
	public Object getObject(String columnLabel) throws InvalidResultSetAccessException {
		return getObject(findColumn(columnLabel));
	}

	
See Also:
getObject.getObject(int, Map)/**
	 * @see java.sql.ResultSet#getObject(int, Map)
	 */
	@Override
	public Object getObject(int columnIndex, Map<String, Class<?>> map) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getObject(columnIndex, map);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getObject.getObject(String, Map)/**
	 * @see java.sql.ResultSet#getObject(String, Map)
	 */
	@Override
	public Object getObject(String columnLabel, Map<String, Class<?>> map) throws InvalidResultSetAccessException {
		return getObject(findColumn(columnLabel), map);
	}

	
See Also:
getObject.getObject(int, Class)/**
	 * @see java.sql.ResultSet#getObject(int, Class)
	 */
	@Override
	public <T> T getObject(int columnIndex, Class<T> type) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getObject(columnIndex, type);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getObject.getObject(String, Class)/**
	 * @see java.sql.ResultSet#getObject(String, Class)
	 */
	@Override
	public <T> T getObject(String columnLabel, Class<T> type) throws InvalidResultSetAccessException {
		return getObject(findColumn(columnLabel), type);
	}

	
See Also:
getShort.getShort(int)/**
	 * @see java.sql.ResultSet#getShort(int)
	 */
	@Override
	public short getShort(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getShort(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getShort.getShort(String)/**
	 * @see java.sql.ResultSet#getShort(String)
	 */
	@Override
	public short getShort(String columnLabel) throws InvalidResultSetAccessException {
		return getShort(findColumn(columnLabel));
	}

	
See Also:
getString.getString(int)/**
	 * @see java.sql.ResultSet#getString(int)
	 */
	@Override
	public String getString(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getString(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getString.getString(String)/**
	 * @see java.sql.ResultSet#getString(String)
	 */
	@Override
	public String getString(String columnLabel) throws InvalidResultSetAccessException {
		return getString(findColumn(columnLabel));
	}

	
See Also:
getTime.getTime(int)/**
	 * @see java.sql.ResultSet#getTime(int)
	 */
	@Override
	public Time getTime(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getTime(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getTime.getTime(String)/**
	 * @see java.sql.ResultSet#getTime(String)
	 */
	@Override
	public Time getTime(String columnLabel) throws InvalidResultSetAccessException {
		return getTime(findColumn(columnLabel));
	}

	
See Also:
getTime.getTime(int, Calendar)/**
	 * @see java.sql.ResultSet#getTime(int, Calendar)
	 */
	@Override
	public Time getTime(int columnIndex, Calendar cal) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getTime(columnIndex, cal);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getTime.getTime(String, Calendar)/**
	 * @see java.sql.ResultSet#getTime(String, Calendar)
	 */
	@Override
	public Time getTime(String columnLabel, Calendar cal) throws InvalidResultSetAccessException {
		return getTime(findColumn(columnLabel), cal);
	}

	
See Also:
getTimestamp.getTimestamp(int)/**
	 * @see java.sql.ResultSet#getTimestamp(int)
	 */
	@Override
	public Timestamp getTimestamp(int columnIndex) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getTimestamp(columnIndex);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getTimestamp.getTimestamp(String)/**
	 * @see java.sql.ResultSet#getTimestamp(String)
	 */
	@Override
	public Timestamp getTimestamp(String columnLabel) throws InvalidResultSetAccessException {
		return getTimestamp(findColumn(columnLabel));
	}

	
See Also:
getTimestamp.getTimestamp(int, Calendar)/**
	 * @see java.sql.ResultSet#getTimestamp(int, Calendar)
	 */
	@Override
	public Timestamp getTimestamp(int columnIndex, Calendar cal) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getTimestamp(columnIndex, cal);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getTimestamp.getTimestamp(String, Calendar)/**
	 * @see java.sql.ResultSet#getTimestamp(String, Calendar)
	 */
	@Override
	public Timestamp getTimestamp(String columnLabel, Calendar cal) throws InvalidResultSetAccessException {
		return getTimestamp(findColumn(columnLabel), cal);
	}


	// RowSet navigation methods

	
See Also:
absolute.absolute(int)/**
	 * @see java.sql.ResultSet#absolute(int)
	 */
	@Override
	public boolean absolute(int row) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.absolute(row);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
afterLast.afterLast()/**
	 * @see java.sql.ResultSet#afterLast()
	 */
	@Override
	public void afterLast() throws InvalidResultSetAccessException {
		try {
			this.resultSet.afterLast();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
beforeFirst.beforeFirst()/**
	 * @see java.sql.ResultSet#beforeFirst()
	 */
	@Override
	public void beforeFirst() throws InvalidResultSetAccessException {
		try {
			this.resultSet.beforeFirst();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
first.first()/**
	 * @see java.sql.ResultSet#first()
	 */
	@Override
	public boolean first() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.first();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
getRow.getRow()/**
	 * @see java.sql.ResultSet#getRow()
	 */
	@Override
	public int getRow() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.getRow();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
isAfterLast.isAfterLast()/**
	 * @see java.sql.ResultSet#isAfterLast()
	 */
	@Override
	public boolean isAfterLast() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.isAfterLast();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
isBeforeFirst.isBeforeFirst()/**
	 * @see java.sql.ResultSet#isBeforeFirst()
	 */
	@Override
	public boolean isBeforeFirst() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.isBeforeFirst();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
isFirst.isFirst()/**
	 * @see java.sql.ResultSet#isFirst()
	 */
	@Override
	public boolean isFirst() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.isFirst();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
isLast.isLast()/**
	 * @see java.sql.ResultSet#isLast()
	 */
	@Override
	public boolean isLast() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.isLast();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
last.last()/**
	 * @see java.sql.ResultSet#last()
	 */
	@Override
	public boolean last() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.last();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
next.next()/**
	 * @see java.sql.ResultSet#next()
	 */
	@Override
	public boolean next() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.next();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
previous.previous()/**
	 * @see java.sql.ResultSet#previous()
	 */
	@Override
	public boolean previous() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.previous();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
relative.relative(int)/**
	 * @see java.sql.ResultSet#relative(int)
	 */
	@Override
	public boolean relative(int rows) throws InvalidResultSetAccessException {
		try {
			return this.resultSet.relative(rows);
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

	
See Also:
wasNull.wasNull()/**
	 * @see java.sql.ResultSet#wasNull()
	 */
	@Override
	public boolean wasNull() throws InvalidResultSetAccessException {
		try {
			return this.resultSet.wasNull();
		}
		catch (SQLException se) {
			throw new InvalidResultSetAccessException(se);
		}
	}

}