uk.ac.starlink.table

Interface RowAccess

All Superinterfaces:

AutoCloseable, Closeable, RowData

All Known Implementing Classes:

EmptyRowSequence, WrapperRowAccess

public interface RowAccess
extends RowData, Closeable

Provides random access to table data. An instance of this class is not in general safe for use from multiple threads.

Since:

24 Jul 2020

Author:

Mark Taylor

Method Summary

Modifier and Type	Method and Description
void	close() Closes this reader.
Object	getCell(int icol) Returns the contents of a given cell at the current row.
Object[]	getRow() Returns the contents of all the cells at the current row.
void	setRowIndex(long irow) Sets the row index to which subsequent data accesses will refer.

Method Detail

setRowIndex

void setRowIndex(long irow)
          throws IOException

Sets the row index to which subsequent data accesses will refer.

This method must be called before the first invocation of getCell(int)/getRow(), otherwise behaviour is undefined (but implementations will likely throw an unchecked exception on subsequent getCell/getRow calls). The effect of setting the value to an out of range value is undefined; it may throw an exception here, or during subsequent calls, or behave otherwise.

Parameters:

irow - row index

Throws:

IOException

getCell

Object getCell(int icol)
        throws IOException

Returns the contents of a given cell at the current row.

Behaviour is undefined if the row index has not been set, or has been set to a value for which no table row exists; however implementations are encouraged to throw suitable RuntimeException in this case.

Specified by:

getCell in interface RowData

Parameters:

icol - column index

Returns:

contents of given column at current row

Throws:

IOException - if there's a problem reading the value

getRow

Object[] getRow()
         throws IOException

Returns the contents of all the cells at the current row.

Note the returned object may be reused between invocations,

Behaviour is undefined if the row index has not been set, or has been set to a value for which no table row exists; however implementations are encouraged to throw a suitable RuntimeException in this case.

Specified by:

getRow in interface RowData

Returns:

array with one element for each column in the table

Throws:

IOException

close

void close()
    throws IOException

Closes this reader. The effect of calling any of the other methods following a close is undefined.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException