uk.ac.starlink.table

Class IteratorRowSequence

java.lang.Object

uk.ac.starlink.table.IteratorRowSequence

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, RowData, RowSequence, Sequence

public class IteratorRowSequence
extends java.lang.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

Nested Classes

Modifier and Type	Class and Description
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

Constructors

Constructor and Description
IteratorRowSequence(java.util.Iterator<java.lang.Object[]> rowIt) Constructs a new RowSequence from an Iterator.

Method Summary

Modifier and Type	Method and Description
void	close() Indicates that this sequence will not be required any more.
java.lang.Object	getCell(int icol) Returns the contents of a cell in the current row.
java.lang.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 advance 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(java.util.Iterator<java.lang.Object[]> 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 java.io.IOException

Description copied from interface: RowSequence

Attempts to advance 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

Specified by:

next in interface Sequence

Returns:

true iff this sequence has been advanced to the next row

Throws:

java.io.IOException - if there is some error

getRow

public java.lang.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 RowData

Specified by:

getRow in interface RowSequence

Returns:

an array of the objects in each cell in row irow

getCell

public java.lang.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 RowData

Specified by:

getCell in interface RowSequence

Parameters:

icol - column index

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 java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface RowSequence