uk.ac.starlink.table
Class ConcatStarTable

java.lang.Object
  extended by uk.ac.starlink.table.WrapperStarTable
      extended by uk.ac.starlink.table.ConcatStarTable
All Implemented Interfaces:
StarTable

public class ConcatStarTable
extends WrapperStarTable

StarTable implementation which concatenates several tables together top-to-bottom. A (possibly blank) metadata table is supplied to define the column and table metadata for the result, and other data tables are added on one way or another, depending which constructor is used. The columns of each data table must be compatible with the columns of the metadata table, or the the data will not be included.

Since:
29 Mar 2004

Field Summary
 
Fields inherited from class uk.ac.starlink.table.WrapperStarTable
baseTable
 
Constructor Summary
ConcatStarTable(StarTable meta, java.util.Iterator tableIt)
          Constructs a concatenated table from a metadata table and an iterator over data-bearing tables.
ConcatStarTable(StarTable meta, StarTable[] tables)
          Constructs a concatenated table from a metadata table and an array of data-bearing tables.
 
Method Summary
 java.lang.Object getCell(long irow, int icol)
          Returns the contents of a given table cell.
 java.lang.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, setName, setParameter, setURL, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

ConcatStarTable

public ConcatStarTable(StarTable meta,
                       java.util.Iterator tableIt)
Constructs a concatenated table from a metadata table and an iterator over data-bearing tables. If any of the tables supplied by the iterator are incompatible with the metadata in meta a warning message is issued through the logging system and its rows are ignored.

Parameters:
meta - table supplying column and table metadata for this one; its row count is ignored and its data is never read
tableIt - iterator over constituent StarTables which taken in sequence supply the row data for this one

ConcatStarTable

public ConcatStarTable(StarTable meta,
                       StarTable[] tables)
                throws java.io.IOException
Constructs a concatenated table from a metadata table and an array of data-bearing tables. If any of tables are incompatible with the metadata in meta an IOException is thrown.

Parameters:
meta - table supplying column and table metadata for this one; its row count is ignored and its data is never read
tables - array of tables which taken in sequence supply the row data for this one
Throws:
java.io.IOException - if any of tables are not compatible with meta
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

getCell

public java.lang.Object getCell(long irow,
                                int icol)
                         throws java.io.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:
java.io.IOException - if there is an error reading the data

getRow

public java.lang.Object[] getRow(long irow)
                          throws java.io.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:
java.io.IOException - if there is an error reading the data

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

getRowSequence

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

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