uk.ac.starlink.table
Class IteratorRowSequence

java.lang.Object
  extended by uk.ac.starlink.table.IteratorRowSequence
All Implemented Interfaces:
RowSequence

public class IteratorRowSequence
extends Object
implements RowSequence

Implementation of RowSequence based on an Iterator which returns table rows in sequence. The iterator's next method may throw an exception of the (unchecked) type IteratorRowSequence.PackagedIOException if it needs to throw something (Iterator.next is not declared to throw any checked exceptions).


Nested Class Summary
static class IteratorRowSequence.PackagedIOException
          Unchecked exception class to be used for smuggling IOExceptions out of the next method of an Iterator for use by IteratorRowSequence
 
Constructor Summary
IteratorRowSequence(Iterator rowIt)
          Constructs a new RowSequence from an Iterator.
 
Method Summary
 void close()
          Indicates that this sequence will not be required any more.
 Object getCell(int icol)
          Returns the contents of a cell in the current row.
 Object[] getRow()
          Returns the contents of the current table row, as an array with the same number of elements as there are columns in this table.
 boolean next()
          Attempts to advances the current row to the next one.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

IteratorRowSequence

public IteratorRowSequence(Iterator rowIt)
Constructs a new RowSequence from an Iterator. Each object returned by the iterator's next method must be an Object[] array representing the data in the next table row (it must have one element for each column). The next method may throw IteratorRowSequence.PackagedIOExceptions.

Parameters:
rowIt - iterator over the rows
Method Detail

next

public boolean next()
             throws IOException
Description copied from interface: RowSequence
Attempts to advances the current row to the next one. If true is returned the attempt has been successful, and if false is returned there are no more rows in this sequence. Since the initial position of a RowSequence is before the first row, this method must be called before current row data can be accessed using the RowSequence.getCell(int) or RowSequence.getRow() methods.

Specified by:
next in interface RowSequence
Returns:
true iff this sequence has been advanced to the next row
Throws:
IOException - if there is some error

getRow

public Object[] getRow()
Description copied from interface: RowSequence
Returns the contents of the current table row, as an array with the same number of elements as there are columns in this table. An unchecked exception will be thrown if there is no current row (next has not yet been called).

Specified by:
getRow in interface RowSequence
Returns:
an array of the objects in each cell in row irow

getCell

public Object getCell(int icol)
Description copied from interface: RowSequence
Returns the contents of a cell in the current row. The class of the returned object should be the same as, or a subclass of, the class returned by getColumnInfo(icol).getContentClass(). An unchecked exception will be thrown if there is no current row (next has not yet been called).

Specified by:
getCell in interface RowSequence
Returns:
the contents of cell icol in the current row

close

public void close()
Description copied from interface: RowSequence
Indicates that this sequence will not be required any more. This should release resources associated with this object. The effect of calling any of the other methods following a close is undefined.

Specified by:
close in interface RowSequence

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