uk.ac.starlink.table
Class ConcatStarTable

java.lang.Object
  |
  +--uk.ac.starlink.table.WrapperStarTable
        |
        +--uk.ac.starlink.table.ConcatStarTable
All Implemented Interfaces:
StarTable

public class ConcatStarTable
extends WrapperStarTable

Table representing the concatenation of rows from two tables. The first (base) table provides all the metadata plus the first lot of rows, and the second (secondary) one provides only additional rows. Of course it must be specified which columns in the secondary table correspond to the columns in the base.

Since:
26 Mar 2004

Field Summary
 
Fields inherited from class uk.ac.starlink.table.WrapperStarTable
baseTable
 
Constructor Summary
ConcatStarTable(StarTable base, StarTable secondary, int[] colMap)
          Constructs a new concatenated table.
 
Method Summary
 Object getCell(long irow, int icol)
          Returns the contents of a given table cell.
 Object[] getRow(long irow)
          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
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ConcatStarTable

public ConcatStarTable(StarTable base,
                       StarTable secondary,
                       int[] colMap)
Constructs a new concatenated table. The supplied colMap array defines which columns in the secondary correspond to which columns in the base; colMap[iBase]=iSecondary means that the data in column iBase of this table are supplied from column iSecondary of secondary. If iSecondary<0 or colMap.length<=iBase then the cells in column iBase are all null for the secondary part of the table.

Parameters:
base - base table
secondary - secondary table
colMap - mapping of columns in the base to columns in the secondary
Method Detail

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

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

getCell

public Object getCell(long irow,
                      int icol)
               throws IOException
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:
irow - the index of the cell's row
icol - the index of the cell's column
Returns:
the contents of this cell
Throws:
IOException - if there is an error reading the data

getRow

public Object[] getRow(long irow)
                throws IOException
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:
irow - the index of the row to retrieve
Returns:
an array of the objects in each cell in row irow
Throws:
IOException - if there is an error reading the data

getRowSequence

public RowSequence getRowSequence()
                           throws IOException
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
Throws:
IOException - if there is an error providing access

Copyright © 2004 CLRC: Central Laboratory of the Research Councils. All rights reserved.