uk.ac.starlink.table.jdbc

Class StarResultSet

java.lang.Object

uk.ac.starlink.table.jdbc.StarResultSet

public class StarResultSet
extends Object

Wraps the ResultSet class to provide the functions which are required to provide StarTable functionality.

Since:

23 Jul 2007

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
StarResultSet(ResultSet rset) Constructs a StarResultSet with default type mapping behaviour.
StarResultSet(ResultSet rset, TypeMapper typeMapper) Constructs a StarResultSet with given type mapping behaviour.

Method Summary

Modifier and Type	Method and Description
RowSequence	createRowSequence() Returns a sequential RowSequence based on this object.
Object	getCell(int icol) Returns the object at a given column in the current row of this result set in a form suitable for use as the content of a StarTable cell.
List<ValueInfo>	getColumnAuxDataInfos() Returns an ordered list of ValueInfo objects representing the auxilliary metadata returned by this object's ColumnInfo objects.
ColumnInfo[]	getColumnInfos() Returns the array of column metadata objects corresponding to the columns in this result set.
ResultSet	getResultSet() Returns the result set on which this table is based.
Object[]	getRow() Returns the current row of this result set in a form suitable for use as the content of a StarTable.
long	getRowCount() Lazily counts the number of rows in this result set, if it has random access.
boolean	isRandom() Indicates whether this result set can be used for random access.
void	setRowIndex(long lrow) Sets the row index from which subsequent getCell(int) and getRow() calls will read.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StarResultSet

public StarResultSet(ResultSet rset)
              throws SQLException

Constructs a StarResultSet with default type mapping behaviour.

Parameters:

rset - result set

Throws:

SQLException

StarResultSet

public StarResultSet(ResultSet rset,
                     TypeMapper typeMapper)
              throws SQLException

Constructs a StarResultSet with given type mapping behaviour.

Parameters:

rset - result set

typeMapper - handles conversion of JDBC types to cell types

Throws:

SQLException

Method Detail

getResultSet

public ResultSet getResultSet()

Returns the result set on which this table is based.

Returns:

result set

getColumnInfos

public ColumnInfo[] getColumnInfos()

Returns the array of column metadata objects corresponding to the columns in this result set.

Returns:

column info array (not a copy)

isRandom

public boolean isRandom()

Indicates whether this result set can be used for random access.

Returns:

true iff random access is possible

getRowCount

public long getRowCount()

Lazily counts the number of rows in this result set, if it has random access. Otherwise, returns -1 (unknown), since a count may be very expensive. If the count cannot be calculated for a random access table for some reason, zero is returned and a warning is logged.

Returns:

row count

getColumnAuxDataInfos

public List<ValueInfo> getColumnAuxDataInfos()

Returns an ordered list of ValueInfo objects representing the auxilliary metadata returned by this object's ColumnInfo objects.

Returns:

an unmodifiable ordered set of known metadata keys

See Also:

StarTable.getColumnAuxDataInfos()

setRowIndex

public void setRowIndex(long lrow)
                 throws IOException

Sets the row index from which subsequent getCell(int) and getRow() calls will read. Callers may need to worry about synchronization.

Parameters:

lrow - row index (0-based)

Throws:

UnsupportedOperationException - for non-random result sets

IOException

getCell

public Object getCell(int icol)
               throws IOException

Returns the object at a given column in the current row of this result set in a form suitable for use as the content of a StarTable cell. Callers may need to worry about synchronization.

Parameters:

icol - the column to use (first column is 0)

Returns:

the cell value

Throws:

IOException

getRow

public Object[] getRow()
                throws IOException

Returns the current row of this result set in a form suitable for use as the content of a StarTable. Callers may need to worry about synchronization.

Returns:

array of cell values in current row

Throws:

IOException

createRowSequence

public RowSequence createRowSequence()
                              throws IOException

Returns a sequential RowSequence based on this object. This assumes that the cursor is currently at the beginning of the result set - no checking is performed here.

Returns:

row sequence

Throws:

IOException