uk.ac.starlink.table

Class WrapperRowAccess

java.lang.Object

uk.ac.starlink.table.WrapperRowAccess

All Implemented Interfaces:

Closeable, AutoCloseable, RowAccess, RowData

public class WrapperRowAccess
extends Object
implements RowAccess

RowAccess which wraps another RowAccess. This class acts as a wrapper around an existing 'base' RowSequence object; all its methods are implemented by forwarding them to the corresponding methods of that base sequence.

This class is provided so that it can be extended by subclasses which modify the view of the base sequence in useful ways.

Since:

24 Jul 2020

Author:

Mark Taylor (Starlink)

See Also:

WrapperStarTable

Constructor Summary

Constructors

Constructor and Description
WrapperRowAccess(RowAccess baseAcc) Constructs a new RowAccess based on a given one.
WrapperRowAccess(RowAccess baseAcc, RowData data) Constructs a new RowAccess based on a given one but with a supplied data access implementation.

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.
String	toString() Returns an indication of the wrapper structure of this object.

Methods inherited from class java.lang.Object

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

Constructor Detail

WrapperRowAccess

public WrapperRowAccess(RowAccess baseAcc)

Constructs a new RowAccess based on a given one.

Parameters:

baseAcc - the base row access

WrapperRowAccess

public WrapperRowAccess(RowAccess baseAcc,
                        RowData data)

Constructs a new RowAccess based on a given one but with a supplied data access implementation.

Parameters:

baseAcc - the base row access

data - RowData object whose methods will be used to implement the getCell and getRow methods

Method Detail

setRowIndex

public void setRowIndex(long irow)
                 throws IOException

Description copied from interface: RowAccess

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

This method must be called before the first invocation of RowAccess.getCell(int)/RowAccess.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.

Specified by:

setRowIndex in interface RowAccess

Parameters:

irow - row index

Throws:

IOException

getCell

public Object getCell(int icol)
               throws IOException

Description copied from interface: RowAccess

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 RowAccess

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

public Object[] getRow()
                throws IOException

Description copied from interface: RowAccess

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 RowAccess

Specified by:

getRow in interface RowData

Returns:

array with one element for each column in the table

Throws:

IOException

close

public void close()
           throws IOException

Description copied from interface: RowAccess

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

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface RowAccess

Throws:

IOException

toString

public String toString()

Returns an indication of the wrapper structure of this object.

Overrides:

toString in class Object

Returns:

string representation