Mercurial > hg > monetdb-java

changeset 187:daa1a4c70879

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For MonetresultSet class: added method checkNotClosed() and invocation for all methods which should test it. This makes the behavior more robust and compliant with JDBC spec in case the ResultSet object was closed. Also changed 3 variables from public access into protected. For rsmdw class: added method checkColumnIndexValidity() and invocation for all relevant ResultSetMetaData methods. Previously when a method was called with column nr 0 it would not throw an exception. Now it does. Added made the internal array variables final.
author Martin van Dinther <martin.van.dinther@monetdbsolutions.com>
date Thu, 12 Oct 2017 18:50:18 +0200 (2017-10-12)
parents 4767b005a531
children 6cad43917d6e
files src/main/java/nl/cwi/monetdb/jdbc/MonetResultSet.java
diffstat 1 files changed, 191 insertions(+), 168 deletions(-) [+]
line wrap: on
line diff
--- a/src/main/java/nl/cwi/monetdb/jdbc/MonetResultSet.java
+++ b/src/main/java/nl/cwi/monetdb/jdbc/MonetResultSet.java
@@ -70,14 +70,9 @@ public class MonetResultSet
 	extends MonetWrapper
 	implements ResultSet, AutoCloseable
 {
-	// the following have default access modifier for the MonetVirtualResultSet subclass
-	/** The current line of the buffer split in columns */
-	final TupleLineParser tlp;
-	/** The current position of the cursor for this ResultSet object */
-	int curRow = 0;
-
-	// a blank final is immutable once assigned in the constructor
-	/** A Header to retrieve lines from */
+	/** The parental Statement object */
+	private final Statement statement;
+	/** A Header to retrieve lines from. Note: it will be null in case of a MonetVirtualResultSet ! */
 	private final MonetConnection.ResultSetResponse header;
 	/** The names of the columns in this ResultSet */
 	private final String[] columns;
@@ -85,11 +80,15 @@ public class MonetResultSet
 	private final String[] types;
 	/** The JDBC SQL types of the columns in this ResultSet. The content will be derived from the MonetDB types[] */
 	private final int[] JdbcSQLTypes;
+
+	// the following have protected access modifier for the MonetVirtualResultSet subclass
+	// they are accessed from MonetVirtualResultSet.absolute()
+	/** The current line of the buffer split in columns */
+	protected final TupleLineParser tlp;
+	/** The current position of the cursor for this ResultSet object */
+	protected int curRow = 0;
 	/** The number of rows in this ResultSet */
-	final int tupleCount;
-
-	/** The parental Statement object */
-	private final Statement statement;
+	protected final int tupleCount;
 
 	/** The type of this ResultSet (forward or scrollable) */
 	private int type = TYPE_FORWARD_ONLY;
@@ -246,13 +245,11 @@ public class MonetResultSet
 	 */
 	@Override
 	public boolean absolute(int row) throws SQLException {
+		checkNotClosed();
 		if (row != curRow + 1 && type == TYPE_FORWARD_ONLY)
 			throw new SQLException("(Absolute) positioning not allowed on forward " +
 				" only result sets!", "M1M05");
 
-		if (header.isClosed())
-			throw new SQLException("ResultSet is closed!", "M1M20");
-
 		// first calculate what the JDBC row is
 		if (row < 0) {
 			// calculate the negatives...
@@ -264,13 +261,13 @@ public class MonetResultSet
 		else if (row > tupleCount + 1)
 			row = tupleCount + 1;	// after last
 
-		String tmpLine = header.getLine(row - 1);
-
 		// store it
 		curRow = row;
 
+		String tmpLine = (header != null) ? header.getLine(row - 1) : null;
 		if (tmpLine == null)
 			return false;
+
 		try {
 			tlp.parse(tmpLine);
 		} catch (MCLParseException e) {
@@ -337,10 +334,12 @@ public class MonetResultSet
 	 *
 	 * @param columnLabel the name of the column
 	 * @return the column index of the given column name
-	 * @throws SQLException if the ResultSet object does not contain columnLabel
+	 * @throws SQLException if the ResultSet object does not contain a column labeled columnLabel,
+	 *	a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public int findColumn(String columnLabel) throws SQLException {
+		checkNotClosed();
 		if (columnLabel != null) {
 			final int array_size = columns.length;
 			for (int i = 0; i < array_size; i++) {
@@ -416,11 +415,11 @@ public class MonetResultSet
 	 * value as a stream of uninterpreted bytes; if the value is SQL
 	 * NULL, the value returned is null
 	 * @throws SQLException if the columnIndex is not valid; if a
-	 * database access error occurs or this method is called on a closed
-	 * result set
+	 * database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public InputStream getBinaryStream(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			switch (JdbcSQLTypes[columnIndex - 1]) {
 				case Types.BLOB:
@@ -461,8 +460,7 @@ public class MonetResultSet
 	 * value as a stream of uninterpreted bytes; if the value is SQL
 	 * NULL, the result is null
 	 * @throws SQLException if the columnLabel is not valid; if a
-	 * database access error occurs or this method is called on a closed
-	 * result set
+	 * database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public InputStream getBinaryStream(String columnLabel) throws SQLException {
@@ -477,10 +475,11 @@ public class MonetResultSet
 	 * @return a java.io.Reader object that contains the column value;
 	 *         if the value is SQL NULL, the value returned is null in
 	 *         the Java programming language.
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public Reader getCharacterStream(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -555,10 +554,11 @@ public class MonetResultSet
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @return a Blob object representing the SQL BLOB value in the
 	 *         specified column
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public Blob getBlob(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -596,10 +596,11 @@ public class MonetResultSet
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @return a Clob object representing the SQL CLOB value in the
 	 *         specified column
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public Clob getClob(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -671,10 +672,11 @@ public class MonetResultSet
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @return the column value (full precision); if the value is SQL NULL,
 	 *         the value returned is null in the Java programming language.
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public BigDecimal getBigDecimal(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -698,13 +700,14 @@ public class MonetResultSet
 	 * @param scale the number of digits to the right of the decimal point
 	 * @return the column value (full precision); if the value is SQL NULL,
 	 *         the value returned is null in the Java programming language.
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	@Deprecated
 	public BigDecimal getBigDecimal(int columnIndex, int scale)
 		throws SQLException
 	{
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -763,10 +766,12 @@ public class MonetResultSet
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @return the column value; if the value is SQL NULL, the value returned
 	 *         is false
-	 * @throws SQLException if there is no such column
+	 * @throws SQLException if the columnIndex is not valid; if a database access error occurs
+	 *	or this method is called on a closed result set
 	 */
 	@Override
 	public boolean getBoolean(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -845,10 +850,11 @@ public class MonetResultSet
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @return the column value; if the value is SQL NULL, the value returned
 	 *         is 0
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public byte getByte(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -886,10 +892,11 @@ public class MonetResultSet
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @return the column value; if the value is SQL NULL, the value returned
 	 *         is null
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public byte[] getBytes(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -990,12 +997,12 @@ public class MonetResultSet
 	 * ResultSet object as a double in the Java programming language.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is 0
-	 * @throws SQLException if there is no such column
+	 * @return the column value; if the value is SQL NULL, the value returned is 0
+	 * @throws SQLException if there is no such column or this method is called on a closed result set
 	 */
 	@Override
 	public double getDouble(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -1016,8 +1023,7 @@ public class MonetResultSet
 	 * ResultSet object as a double in the Java programming language.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is 0
+	 * @return the column value; if the value is SQL NULL, the value returned is 0
 	 * @throws SQLException if the ResultSet object does not contain columnLabel
 	 */
 	@Override
@@ -1039,7 +1045,6 @@ public class MonetResultSet
 
 	/**
 	 * Retrieves the fetch direction for this ResultSet object.
-	 * <b>currently not implemented</b>
 	 *
 	 * @return the current fetch direction for this ResultSet object
 	 */
@@ -1053,7 +1058,6 @@ public class MonetResultSet
 	 * object will be processed. The initial value is determined by the
 	 * Statement object that produced this ResultSet object.
 	 * The fetch direction may be changed at any time.
-	 * <b>currently not implemented</b>
 	 *
 	 * @param direction - an int specifying the suggested fetch direction;
 	 * one of ResultSet.FETCH_FORWARD, ResultSet.FETCH_REVERSE, or ResultSet.FETCH_UNKNOWN
@@ -1110,12 +1114,12 @@ public class MonetResultSet
 	 * ResultSet object as a float in the Java programming language.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is 0
-	 * @throws SQLException if there is no such column
+	 * @return the column value; if the value is SQL NULL, the value returned is 0
+	 * @throws SQLException if there is no such column or this method is called on a closed result set
 	 */
 	@Override
 	public float getFloat(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -1150,10 +1154,11 @@ public class MonetResultSet
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @return the column value; if the value is SQL NULL, the value returned is 0
-	 * @throws SQLException if there is no such column
+	 * @throws SQLException if there is no such column or this method is called on a closed result set
 	 */
 	@Override
 	public int getInt(int columnIndex) throws SQLException {
+		checkNotClosed();
 		String val = "";
 		try {
 			val = tlp.values[columnIndex - 1];
@@ -1201,10 +1206,11 @@ public class MonetResultSet
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @return the column value; if the value is SQL NULL, the value returned is 0
-	 * @throws SQLException if there is no such column
+	 * @throws SQLException if there is no such column or this method is called on a closed result set
 	 */
 	@Override
 	public long getLong(int columnIndex) throws SQLException {
+		checkNotClosed();
 		String val = "";
 		try {
 			val = tlp.values[columnIndex - 1];
@@ -1238,8 +1244,7 @@ public class MonetResultSet
 	 * ResultSet object as a long in the Java programming language.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is 0
+	 * @return the column value; if the value is SQL NULL, the value returned is 0
 	 * @throws SQLException if the ResultSet object does not contain columnLabel
 	 */
 	@Override
@@ -1247,6 +1252,7 @@ public class MonetResultSet
 		return getLong(findColumn(columnLabel));
 	}
 
+
 	/* helper for the anonymous class inside getMetaData */
 	private abstract class rsmdw extends MonetWrapper implements ResultSetMetaData {}
 	/**
@@ -1261,16 +1267,25 @@ public class MonetResultSet
 		return new rsmdw() {
 			// for the more expensive methods (getPrecision(), getScale(), isNullable()), we provide a simple cache
 			// caches to store precision, scale and isNullable values from getColumns()
-			final int array_size = columns.length + 1;  // add 1 as in JDBC columns start from 1 (array from 0).
-			private boolean[] _is_fetched	= new boolean[array_size];
-			private int[] _precision	= new int[array_size];
-			private int[] _scale		= new int[array_size];
-			private int[] _isNullable	= new int[array_size];
-			private boolean[] _isAutoincrement = new boolean[array_size];
+			private final int array_size = columns.length + 1;  // add 1 as in JDBC columns start from 1 (array from 0).
+			private final boolean[] _is_fetched	= new boolean[array_size];
+			private final int[] _precision	= new int[array_size];
+			private final int[] _scale		= new int[array_size];
+			private final int[] _isNullable	= new int[array_size];
+			private final boolean[] _isAutoincrement = new boolean[array_size];
 			private Connection conn = null;
 			private DatabaseMetaData dbmd = null;
 
 			/**
+			 * A private utility method to check validity of column index number
+			 * @throws an SQLDataException when invalid column index number
+			 */
+			private void checkColumnIndexValidity(int column) throws SQLDataException {
+				if (column < 1 || column > columns.length)
+					throw MonetResultSet.newSQLInvalidColumnIndexException(column);
+			}
+
+			/**
 			 * A private method to fetch the precision, scale, isNullable and isAutoincrement value for a fully qualified column.
 			 * As md.getColumns() is an expensive method we call it only once per column
 			 * and cache the precision, scale, isNullable and isAutoincrement values in the above array chaches.
@@ -1278,8 +1293,7 @@ public class MonetResultSet
 			 */
 			private void fetchColumnInfo(int column) throws SQLException
 			{
-				if (column <= 0 || column > columns.length)
-					throw newSQLInvalidColumnIndexException(column);
+				checkColumnIndexValidity(column);
 
 				_is_fetched[column] = true;
 				_precision[column] = 0;
@@ -1342,13 +1356,14 @@ public class MonetResultSet
 			 */
 			@Override
 			public boolean isAutoIncrement(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				try {
 					if (_is_fetched[column] != true) {
 						fetchColumnInfo(column);
 					}
 					return _isAutoincrement[column];
 				} catch (IndexOutOfBoundsException e) {
-					throw newSQLInvalidColumnIndexException(column);
+					throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 				}
 			}
 
@@ -1392,7 +1407,8 @@ public class MonetResultSet
 			 * @returns true
 			 */
 			@Override
-			public boolean isSearchable(int column) {
+			public boolean isSearchable(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				return true;
 			}
 
@@ -1407,7 +1423,8 @@ public class MonetResultSet
 			 * @returns false
 			 */
 			@Override
-			public boolean isCurrency(int column) {
+			public boolean isCurrency(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				return false;
 			}
 			
@@ -1462,12 +1479,13 @@ public class MonetResultSet
 			 */
 			@Override
 			public int getColumnDisplaySize(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				int ret = 1;
 				if (header != null) {
 					try {
 						ret = header.getColumnLengths()[column - 1];
 					} catch (IndexOutOfBoundsException e) {
-						throw newSQLInvalidColumnIndexException(column);
+						throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 					}
 				}
 				return ret;
@@ -1482,6 +1500,7 @@ public class MonetResultSet
 			 */
 			@Override
 			public String getSchemaName(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				if (header != null) {
 					// figure the name out
 					try {
@@ -1491,7 +1510,7 @@ public class MonetResultSet
 							return (dot >= 0) ? schema.substring(0, dot) : "";
 						}
 					} catch (IndexOutOfBoundsException e) {
-						throw newSQLInvalidColumnIndexException(column);
+						throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 					}
 				}
 				return "";
@@ -1505,6 +1524,7 @@ public class MonetResultSet
 			 */
 			@Override
 			public String getTableName(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				if (header != null) {
 					// figure the name out
 					try {
@@ -1514,7 +1534,7 @@ public class MonetResultSet
 							return (dot >= 0) ? table.substring(dot + 1) : table;
 						}
 					} catch (IndexOutOfBoundsException e) {
-						throw newSQLInvalidColumnIndexException(column);
+						throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 					}
 				}
 				return "";
@@ -1532,6 +1552,7 @@ public class MonetResultSet
 			 */
 			@Override
 			public int getPrecision(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				try {
 					if (_is_fetched[column] != true) {
 						fetchColumnInfo(column);
@@ -1590,7 +1611,7 @@ public class MonetResultSet
 					}
 					return _precision[column];
 				} catch (IndexOutOfBoundsException e) {
-					throw newSQLInvalidColumnIndexException(column);
+					throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 				}
 			}
 
@@ -1606,13 +1627,14 @@ public class MonetResultSet
 			 */
 			@Override
 			public int getScale(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				try {
 					if (_is_fetched[column] != true) {
 						fetchColumnInfo(column);
 					}
 					return _scale[column];
 				} catch (IndexOutOfBoundsException e) {
-					throw newSQLInvalidColumnIndexException(column);
+					throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 				}
 			}
 
@@ -1628,13 +1650,14 @@ public class MonetResultSet
 			 */
 			@Override
 			public int isNullable(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				try {
 					if (_is_fetched[column] != true) {
 						fetchColumnInfo(column);
 					}
 					return _isNullable[column];
 				} catch (IndexOutOfBoundsException e) {
-					throw newSQLInvalidColumnIndexException(column);
+					throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 				}
 			}
 
@@ -1648,6 +1671,7 @@ public class MonetResultSet
 			 */
 			@Override
 			public String getCatalogName(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				return null;	// MonetDB does NOT support catalogs
 
 			}
@@ -1661,7 +1685,8 @@ public class MonetResultSet
 			 * @return true if so; false otherwise
 			 */
 			@Override
-			public boolean isReadOnly(int column) {
+			public boolean isReadOnly(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				return true;
 			}
 
@@ -1673,7 +1698,8 @@ public class MonetResultSet
 			 * @return true if so; false otherwise
 			 */
 			@Override
-			public boolean isWritable(int column) {
+			public boolean isWritable(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				return false;
 			}
 
@@ -1685,7 +1711,8 @@ public class MonetResultSet
 			 * @return true if so; false otherwise
 			 */
 			@Override
-			public boolean isDefinitelyWritable(int column) {
+			public boolean isDefinitelyWritable(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				return false;
 			}
 
@@ -1706,6 +1733,7 @@ public class MonetResultSet
 			 */
 			@Override
 			public String getColumnClassName(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				if (conn == null) {
 					// first time, get a Connection object and cache it for all next columns
 					conn = getStatement().getConnection();
@@ -1728,7 +1756,7 @@ public class MonetResultSet
 					}
 					throw new SQLException("column type mapping null: " + MonetDBType, "M0M03");
 				} catch (IndexOutOfBoundsException e) {
-					throw newSQLInvalidColumnIndexException(column);
+					throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 				}
 			}
 
@@ -1755,10 +1783,11 @@ public class MonetResultSet
 			 */
 			@Override
 			public String getColumnName(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				try {
 					return columns[column - 1];
 				} catch (IndexOutOfBoundsException e) {
-					throw newSQLInvalidColumnIndexException(column);
+					throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 				}
 			}
 
@@ -1771,10 +1800,11 @@ public class MonetResultSet
 			 */
 			@Override
 			public int getColumnType(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				try {
 					return JdbcSQLTypes[column - 1];
 				} catch (IndexOutOfBoundsException e) {
-					throw newSQLInvalidColumnIndexException(column);
+					throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 				}
 			}
 
@@ -1789,10 +1819,11 @@ public class MonetResultSet
 			 */
 			@Override
 			public String getColumnTypeName(int column) throws SQLException {
+				checkColumnIndexValidity(column);
 				try {
 					return types[column - 1];
 				} catch (IndexOutOfBoundsException e) {
-					throw newSQLInvalidColumnIndexException(column);
+					throw MonetResultSet.newSQLInvalidColumnIndexException(column);
 				}
 			}
 
@@ -1817,12 +1848,14 @@ public class MonetResultSet
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @return a java.lang.Object holding the column value or null
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public Object getObject(int columnIndex) throws SQLException {
 		// Many generic JDBC programs use getObject(colnr) to retrieve value objects from a resultset
 		// For speed the implementation should be as fast as possible, so avoid method calls (by inlining code) where possible
+		checkNotClosed();
+
 		final int JdbcType;
 		final String val;
 		try {
@@ -1993,15 +2026,15 @@ public class MonetResultSet
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @param map a java.util.Map object that contains the mapping from SQL
 	 *        type names to classes in the Java programming language
-	 * @return an Object in the Java programming language representing the SQL
-	 *         value
-	 * @throws SQLException if a database access error occurs
+	 * @return an Object in the Java programming language representing the SQL value
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	@SuppressWarnings("unchecked")
 	public Object getObject(int columnIndex, Map<String,Class<?>> map)
 		throws SQLException
 	{
+		checkNotClosed();
 		final String val;
 		final String MonetDBtype;
 		try {
@@ -2238,6 +2271,7 @@ public class MonetResultSet
 	 */
 	@Override
 	public <T> T getObject(int columnIndex, Class<T> type) throws SQLException {
+		checkNotClosed();
 		if (type == null)
 			throw new SQLException("type is null", "M1M05");
 
@@ -2341,7 +2375,7 @@ public class MonetResultSet
 	 *
 	 * @param columnLabel the SQL name of the column
 	 * @return a java.lang.Object holding the column value
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public Object getObject(String columnLabel) throws SQLException {
@@ -2358,7 +2392,7 @@ public class MonetResultSet
 	 * @param map a java.util.Map object that contains the mapping from SQL
 	 *        type names to classes in the Java programming language
 	 * @return an Object representing the SQL value in the specified column
-	 * @throws SQLException if a database access error occurs
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public Object getObject(String columnLabel, Map<String,Class<?>> map) throws SQLException {
@@ -2425,12 +2459,12 @@ public class MonetResultSet
 	 * ResultSet object as a short in the Java programming language.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is 0
-	 * @throws SQLException if there is no such column
+	 * @return the column value; if the value is SQL NULL, the value returned is 0
+	 * @throws SQLException if there is no such column or this method is called on a closed result set
 	 */
 	@Override
 	public short getShort(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -2451,8 +2485,7 @@ public class MonetResultSet
 	 * ResultSet object as a short in the Java programming language.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is 0
+	 * @return the column value; if the value is SQL NULL, the value returned is 0
 	 * @throws SQLException if the ResultSet object does not contain columnLabel
 	 */
 	@Override
@@ -2461,12 +2494,12 @@ public class MonetResultSet
 	}
 
 	/**
-	 * Retrieves the Statement object that produced this ResultSet object. If
-	 * the result set was generated some other way, such as by a
-	 * DatabaseMetaData method, this method returns null.
+	 * Retrieves the Statement object that produced this ResultSet object.
+	 * If the result set was generated some other way, such as by a
+	 * DatabaseMetaData method, this method may return null.
 	 *
-	 * @return the Statement object that produced this ResultSet object or null
-	 *         if the result set was produced some other way
+	 * @return the Statement object that produced this ResultSet object or
+	 *         null if the result set was produced some other way
 	 */
 	@Override
 	public Statement getStatement() {
@@ -2478,12 +2511,12 @@ public class MonetResultSet
 	 * ResultSet object as a String in the Java programming language.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
-	 * @throws SQLException if there is no such column
+	 * @return the column value; if the value is SQL NULL, the value returned is null
+	 * @throws SQLException if there is no such column or this method is called on a closed result set
 	 */
 	@Override
 	public String getString(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -2502,8 +2535,7 @@ public class MonetResultSet
 	 * ResultSet object as a String in the Java programming language.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if the ResultSet object does not contain columnLabel
 	 */
 	@Override
@@ -2518,8 +2550,7 @@ public class MonetResultSet
 	 * and LONGNVARCHAR columns.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if there is no such column
 	 * @throws SQLFeatureNotSupportedException the JDBC driver does
 	 *         not support this method
@@ -2536,8 +2567,7 @@ public class MonetResultSet
 	 * and LONGNVARCHAR columns.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if the ResultSet object does not contain columnLabel
 	 * @throws SQLFeatureNotSupportedException the JDBC driver does
 	 *         not support this method
@@ -2597,14 +2627,14 @@ public class MonetResultSet
 	 *
 	 * @param cal the Calendar to use/fill when parsing the date/time
 	 * @param col the column to parse
-	 * @param type the corresponding java.sql.Types type of the calling
-	 *        function
+	 * @param type the corresponding java.sql.Types type of the calling function
 	 * @return the fractional seconds (nanos) or -1 if the value is NULL
 	 * @throws SQLException if a database error occurs
 	 */
 	private int getJavaDate(Calendar cal, int columnIndex, int type)
 		throws SQLException
 	{
+		checkNotClosed();
 		if (cal == null)
 			throw new IllegalArgumentException("No Calendar object given!");
 
@@ -2724,7 +2754,7 @@ public class MonetResultSet
 					}
 					while (ctr++ < 9)
 						nanos *= 10;
-				} catch(MCLParseException e) {
+				} catch (MCLParseException e) {
 					addWarning(e.getMessage() +
 							" found: '" + monDate[e.getErrorOffset()] + "'" +
 							" in: \"" + monetDate + "\"" +
@@ -2748,7 +2778,7 @@ public class MonetResultSet
 	 * @return the intrinsic value of the char
 	 * @throws MCLParseException if c is not a digit
 	 */
-	private final static int getIntrinsicValue(char c, int pos)
+	private static final int getIntrinsicValue(char c, int pos)
 		throws MCLParseException
 	{
 		// note: don't use Character.isDigit() here, because
@@ -2766,8 +2796,7 @@ public class MonetResultSet
 	 * language.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value as a java.sql.Date object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 * @see #getDate(int col, Calendar cal)
 	 */
@@ -2785,14 +2814,14 @@ public class MonetResultSet
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
 	 * @param cal the java.util.Calendar object to use in constructing the date
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value as a java.sql.Date object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
 	public java.sql.Date getDate(int columnIndex, Calendar cal)
 		throws SQLException
 	{
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -2822,10 +2851,8 @@ public class MonetResultSet
 	 * ResultSet object as a java.sql.Date object in the Java programming
 	 * language.
 	 *
-	 * @param columnLabel the SQL name of the column from which to retrieve the
-	 *        value
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @param columnLabel the SQL name of the column from which to retrieve the value
+	 * @return the column value as a java.sql.Date object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
@@ -2840,11 +2867,9 @@ public class MonetResultSet
 	 * millisecond value for the date if the underlying database does not store
 	 * timezone information.
 	 *
-	 * @param columnLabel the SQL name of the column from which to retrieve the
-	 *        value
+	 * @param columnLabel the SQL name of the column from which to retrieve the value
 	 * @param cal the java.util.Calendar object to use in constructing the date
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value as a java.sql.Date object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
@@ -2860,8 +2885,7 @@ public class MonetResultSet
 	 * language.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value as a java.sql.Time object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
@@ -2877,17 +2901,15 @@ public class MonetResultSet
 	 * timezone information.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @param cal the java.util.Calendar object to use in constructing the
-	 *        timestamp
-	 * @return the column value as a java.sql.Time object; if the value is
-	 *         SQL NULL, the value returned is null in the Java programming
-	 *         language
+	 * @param cal the java.util.Calendar object to use in constructing the timestamp
+	 * @return the column value as a java.sql.Time object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
 	public Time getTime(int columnIndex, Calendar cal)
 		throws SQLException
 	{
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -2918,8 +2940,7 @@ public class MonetResultSet
 	 * language.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value as a java.sql.Time object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
@@ -2935,11 +2956,8 @@ public class MonetResultSet
 	 * timezone information.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @param cal the java.util.Calendar object to use in constructing the
-	 *        timestamp
-	 * @return the column value as a java.sql.Time object; if the value is
-	 *         SQL NULL, the value returned is null in the Java programming
-	 *         language
+	 * @param cal the java.util.Calendar object to use in constructing the timestamp
+	 * @return the column value as a java.sql.Time object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
@@ -2955,8 +2973,7 @@ public class MonetResultSet
 	 * language.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value as a java.sql.Timestamp object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
@@ -2972,17 +2989,15 @@ public class MonetResultSet
 	 * store timezone information.
 	 *
 	 * @param columnIndex the first column is 1, the second is 2, ...
-	 * @param cal the java.util.Calendar object to use in constructing the
-	 *        timestamp
-	 * @return the column value as a java.sql.Timestamp object; if the value is
-	 *         SQL NULL, the value returned is null in the Java programming
-	 *         language
+	 * @param cal the java.util.Calendar object to use in constructing the timestamp
+	 * @return the column value as a java.sql.Timestamp object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
 	public Timestamp getTimestamp(int columnIndex, Calendar cal)
 		throws SQLException
 	{
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -3018,8 +3033,7 @@ public class MonetResultSet
 	 * language.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @return the column value; if the value is SQL NULL, the value returned
-	 *         is null
+	 * @return the column value as a java.sql.Timestamp object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
@@ -3035,11 +3049,8 @@ public class MonetResultSet
 	 * store timezone information.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @param cal the java.util.Calendar object to use in constructing the
-	 *        timestamp
-	 * @return the column value as a java.sql.Timestamp object; if the value is
-	 *         SQL NULL, the value returned is null in the Java programming
-	 *         language
+	 * @param cal the java.util.Calendar object to use in constructing the timestamp
+	 * @return the column value as a java.sql.Timestamp object; if the value is SQL NULL, the value returned is null
 	 * @throws SQLException if a database access error occurs
 	 */
 	@Override
@@ -3066,16 +3077,13 @@ public class MonetResultSet
 	 * of this ResultSet object as a java.net.URL object in the Java
 	 * programming language.
 	 *
-	 * @param columnIndex the index of the column 1 is the first,
-	 *                    2 is the second,...
-	 * @return the column value as a java.net.URL object; if the value
-	 *         is SQL NULL, the value returned is null in the Java
-	 *         programming language
-	 * @throws SQLException if a database access error occurs, or if a
-	 *         URL is malformed
+	 * @param columnIndex the index of the column 1 is the first, 2 is the second,...
+	 * @return the column value as a java.net.URL object; if the value is SQL NULL, the value returned is null
+	 * @throws SQLException if a database access error occurs, or if a URL is malformed
 	 */
 	@Override
 	public URL getURL(int columnIndex) throws SQLException {
+		checkNotClosed();
 		try {
 			String val = tlp.values[columnIndex - 1];
 			if (val == null) {
@@ -3099,11 +3107,8 @@ public class MonetResultSet
 	 * programming language.
 	 *
 	 * @param columnLabel the SQL name of the column
-	 * @return the column value as a java.net.URL object; if the value
-	 *         is SQL NULL, the value returned is null in the Java
-	 *         programming language
-	 * @throws SQLException if a database access error occurs, or if a
-	 *         URL is malformed
+	 * @return the column value as a java.net.URL object; if the value is SQL NULL, the value returned is null
+	 * @throws SQLException if a database access error occurs, or if a URL is malformed
 	 */
 	@Override
 	public URL getURL(String columnLabel) throws SQLException {
@@ -3122,14 +3127,11 @@ public class MonetResultSet
 	 * Note: Subsequent warnings will be chained to this SQLWarning.
 	 *
 	 * @return the first SQLWarning object or null if there are none
-	 * @throws SQLException if a database access error occurs or this method is
-	 *         called on a closed connection
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public SQLWarning getWarnings() throws SQLException {
-		if (header != null && header.isClosed())
-			throw new SQLException("Cannot call on closed ResultSet", "M1M20");
-
+		checkNotClosed();
 		// if there are no warnings, this will be null, which fits with the
 		// specification.
 		return warnings;
@@ -3141,9 +3143,11 @@ public class MonetResultSet
 	 *
 	 * @return true if the cursor is after the last row; false if the cursor is
 	 *         at any other position or the result set contains no rows
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
-	public boolean isAfterLast() {
+	public boolean isAfterLast() throws SQLException {
+		checkNotClosed();
 		return curRow == tupleCount + 1;
 	}
 
@@ -3153,9 +3157,11 @@ public class MonetResultSet
 	 *
 	 * @return true if the cursor is before the first row; false if the cursor
 	 *         is at any other position or the result set contains no rows
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
-	public boolean isBeforeFirst() {
+	public boolean isBeforeFirst() throws SQLException {
+		checkNotClosed();
 		return curRow == 0;
 	}
 
@@ -3164,11 +3170,11 @@ public class MonetResultSet
 	 * ResultSet is closed if the method close has been called on it, or
 	 * if it is automatically closed.
 	 *
-	 * @return true if this ResultSet object is closed; false if it is
-	 *         still open
+	 * @return true if this ResultSet object is closed; false if it is still open
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
-	public boolean isClosed() {
+	public boolean isClosed() throws SQLException {
 		return header != null && header.isClosed();
 	}
 
@@ -3177,9 +3183,11 @@ public class MonetResultSet
 	 * object.
 	 *
 	 * @return true if the cursor is on the first row; false otherwise
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
-	public boolean isFirst() {
+	public boolean isFirst() throws SQLException {
+		checkNotClosed();
 		return curRow == 1;
 	}
 
@@ -3187,9 +3195,11 @@ public class MonetResultSet
 	 * Retrieves whether the cursor is on the last row of this ResultSet object.
 	 *
 	 * @return true if the cursor is on the last row; false otherwise
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
-	public boolean isLast() {
+	public boolean isLast() throws SQLException {
+		checkNotClosed();
 		return curRow == tupleCount;
 	}
 
@@ -3200,6 +3210,7 @@ public class MonetResultSet
 	 *         in the result set
 	 * @throws SQLException if a database access error occurs or the result set
 	 *         type is TYPE_FORWARD_ONLY
+	 * @throws SQLException if a database access error occurs or this method is called on a closed result set
 	 */
 	@Override
 	public boolean last() throws SQLException {
@@ -3278,6 +3289,7 @@ public class MonetResultSet
 	 */
 	@Override
 	public boolean rowDeleted() throws SQLException {
+		checkNotClosed();
 		return false;
 	}
 
@@ -3297,6 +3309,7 @@ public class MonetResultSet
 	 */
 	@Override
 	public boolean rowInserted() throws SQLException {
+		checkNotClosed();
 		return false;
 	}
 
@@ -3316,6 +3329,7 @@ public class MonetResultSet
 	 */
 	@Override
 	public boolean rowUpdated() throws SQLException {
+		checkNotClosed();
 		return false;
 	}
 
@@ -3782,8 +3796,7 @@ public class MonetResultSet
 	 * its value and then call the method wasNull to see if the value read was
 	 * SQL NULL.
 	 *
-	 * @return true if the last column value read was SQL NULL and false
-	 *          otherwise
+	 * @return true if the last column value read was SQL NULL and false otherwise
 	 */
 	@Override
 	public boolean wasNull() {
@@ -3801,14 +3814,24 @@ public class MonetResultSet
 	 * @param reason the warning message
 	 */
 	private void addWarning(String reason, String sqlstate) {
+		SQLWarning warng = new SQLWarning(reason, sqlstate);
 		if (warnings == null) {
-			warnings = new SQLWarning(reason, sqlstate);
+			warnings = warng;
 		} else {
-			warnings.setNextWarning(new SQLWarning(reason, sqlstate));
+			warnings.setNextWarning(warng);
 		}
 	}
 
 	/**
+	 * Local helper method to test whether the ResultSet object is closed
+	 * When closed it throws an SQLException
+	 */
+	private void checkNotClosed() throws SQLException {
+		if (isClosed())
+			throw new SQLException("ResultSet is closed", "M1M20");
+	}
+
+	/**
 	 * Small helper method that formats the "Invalid Column Index number ..." message
 	 * and creates a new SQLDataException object whose SQLState is set
 	 * to "22010": invalid indicator parameter value.
@@ -3816,7 +3839,7 @@ public class MonetResultSet
 	 * @param colIdx the column index number
 	 * @return a new created SQLDataException object with SQLState 22010
 	 */
-	public final static SQLDataException newSQLInvalidColumnIndexException(int colIdx) {
+	public static final SQLDataException newSQLInvalidColumnIndexException(int colIdx) {
 		return new SQLDataException("Invalid Column Index number: " + colIdx, "22010");
 	}
 
@@ -3828,7 +3851,7 @@ public class MonetResultSet
 	 * @param error the NumberFormatException
 	 * @return a new created SQLDataException object with SQLState 22003
 	 */
-	private final static SQLDataException newSQLNumberFormatException(NumberFormatException error) {
+	private static final SQLDataException newSQLNumberFormatException(NumberFormatException error) {
 		return new SQLDataException("Could not convert value to a number. " + error.getMessage(), "22003");
 	}
 
@@ -3840,7 +3863,7 @@ public class MonetResultSet
 	 * @param name the method name
 	 * @return a new created SQLFeatureNotSupportedException object with SQLState 0A000
 	 */
-	private final static SQLFeatureNotSupportedException newSQLFeatureNotSupportedException(String name) {
+	private static final SQLFeatureNotSupportedException newSQLFeatureNotSupportedException(String name) {
 		return new SQLFeatureNotSupportedException("Method " + name + " not implemented", "0A000");
 	}
 }