uk.ac.starlink.table
Class EmptyStarTable

java.lang.Object
  uk.ac.starlink.table.WrapperStarTable
      uk.ac.starlink.table.EmptyStarTable

All Implemented Interfaces:

StarTable

public class EmptyStarTable
extends WrapperStarTable

A wrapper table which has the same metadata as its base table, but no rows.

Since:

5 Aug 2004

Field Summary

Fields inherited from class uk.ac.starlink.table.WrapperStarTable

baseTable

Constructor Summary

EmptyStarTable()
Creates a new empty table with no columns, no rows and no parameters.

EmptyStarTable(StarTable baseTable)
Creates a new empty table with metadata taken from an existing one.

Method Summary

java.lang.Object	getCell(long lrow, int icol) Returns the contents of a given table cell.
java.lang.Object[]	getRow(long lrow) Returns the contents of a given table row.
long	getRowCount() Returns the number of rows in this table, if known.
RowSequence	getRowSequence() Returns an object which can iterate over all the rows in the table sequentially.
boolean	isRandom() Indicates whether random access is provided by this table.

Methods inherited from class uk.ac.starlink.table.WrapperStarTable

checkedLongToInt, getBaseTable, getColumnAuxDataInfos, getColumnCount, getColumnInfo, getName, getParameterByName, getParameters, getURL, setName, setParameter, setURL, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

EmptyStarTable

public EmptyStarTable(StarTable baseTable)

Creates a new empty table with metadata taken from an existing one.

Parameters:

baseTable - base table

EmptyStarTable

public EmptyStarTable()

Creates a new empty table with no columns, no rows and no parameters.

Method Detail

isRandom

public boolean isRandom()

Description copied from interface: StarTable

Indicates whether random access is provided by this table. Only if the result is true may the StarTable.getRow(long) and StarTable.getCell(long, int) methods be used.

Specified by:

isRandom in interface StarTable

Overrides:

isRandom in class WrapperStarTable

Returns:

true if table random access methods are available

getRowCount

public long getRowCount()

Description copied from interface: StarTable

Returns the number of rows in this table, if known. If the number of rows cannot be (easily) determined, a value of -1 will be returned.

Specified by:

getRowCount in interface StarTable

Overrides:

getRowCount in class WrapperStarTable

Returns:

the number of rows, or -1

getCell

public java.lang.Object getCell(long lrow,
                                int icol)

Description copied from interface: StarTable

Returns the contents of a given table cell. The class of the returned object should be the same as, or a subclass of, the class returned by getColumnInfo(icol).getContentClass().

Specified by:

getCell in interface StarTable

Overrides:

getCell in class WrapperStarTable

Parameters:

lrow - the index of the cell's row

icol - the index of the cell's column

Returns:

the contents of this cell

getRow

public java.lang.Object[] getRow(long lrow)

Description copied from interface: StarTable

Returns the contents of a given table row. The returned value is equivalent to an array formed of all the objects returned by getCell(irow,icol) for all the columns icol in sequence.

Specified by:

getRow in interface StarTable

Overrides:

getRow in class WrapperStarTable

Parameters:

lrow - the index of the row to retrieve

Returns:

an array of the objects in each cell in row irow

getRowSequence

public RowSequence getRowSequence()

Description copied from interface: StarTable

Returns an object which can iterate over all the rows in the table sequentially.

Specified by:

getRowSequence in interface StarTable

Overrides:

getRowSequence in class WrapperStarTable

Returns:

an object providing sequential access to the table data