uk.ac.starlink.table
Class IteratorRowSequence

java.lang.Object
  |
  +--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 advance(long nrows)
          Moves the current row forward by offset rows.
 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.
 long getRowIndex()
          Returns the index of the current row.
 boolean hasNext()
          Indicates whether this table contains any more rows after the current one.
 void next()
          Advances the current row by 1.
 
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

hasNext

public boolean hasNext()
Description copied from interface: RowSequence
Indicates whether this table contains any more rows after the current one.

Specified by:
hasNext in interface RowSequence
Returns:
true iff another row exists

next

public void next()
          throws IOException
Description copied from interface: RowSequence
Advances the current row by 1. Since the initial value of the current row is -1, next must be called before current row data as accessed by the RowSequence.getCell(int) or RowSequence.getRow() methods are invoked.

Specified by:
next in interface RowSequence
Throws:
IOException - if there is some error in the positioning

advance

public void advance(long nrows)
             throws IOException
Description copied from interface: RowSequence
Moves the current row forward by offset rows.

Specified by:
advance in interface RowSequence
Parameters:
nrows - the number of rows to advance the current row by.
Throws:
IOException - if an attempt to advance beyond the end of the table is made, or if there is some other read 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.

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().

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

getRowIndex

public long getRowIndex()
Description copied from interface: RowSequence
Returns the index of the current row. This starts off at -1 before the first invocation of next.

Specified by:
getRowIndex in interface RowSequence
Returns:
the index of the current row

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