org.axiondb.engine.rowiterators
Class ChainedRowIterator

java.lang.Object
  extended by org.axiondb.engine.rowiterators.BaseRowIterator
      extended by org.axiondb.engine.rowiterators.ChainedRowIterator
All Implemented Interfaces:
RowIterator

public class ChainedRowIterator
extends BaseRowIterator
implements RowIterator

Chains together one or more RowIterators to make them look like one (similiar to a SQL UNION).

Version:
$Revision: 1.14 $ $Date: 2005/12/20 18:32:41 $

Constructor Summary
ChainedRowIterator()
           
 
Method Summary
 void add(Row row)
          Not supported in the base implementation.
 void addRowIterator(RowIterator iter)
           
 Row current()
          Returns the last Rowreturned by me (by RowIterator.next(),RowIterator.previous(), RowIterator.first(),RowIterator.last(), etc.).
 int currentIndex()
          Returns the index of the RowIterator.current()row, if any.
 boolean hasCurrent()
          Returns true if I have a current Row.
 boolean hasNext()
          Returns true if I have more Rows when traversing the list in the forward direction.
 boolean hasPrevious()
          Returns true if I have more Rows when traversing the list in the reverse direction.
 Row last()
          Returns the last Rowin the list, positioning the cursor to just after the last Rowin the list.
 Row next()
          Returns the next Rowin the list, or throws NoSuchElementExceptionif no next Row exists.
 int next(int count)
          Sets the current iterator position to currentIndex() + count; this will not set the current row, peekPrevious() may be used to return the current row.
 int nextIndex()
          Returns the index of the RowIterator.next()row, if any, or the number of elements is the iterator if we've reached the end.
 Row previous()
          Returns the previous Rowin the list, or throws NoSuchElementExceptionif no next Row exists.
 int previous(int count)
          Sets the current iterator position to currentIndex() - count; this will not set the current row, peekNext() may be used to return the current row.
 int previousIndex()
          Returns the index of the RowIterator.previous()row, if any, or -1 if we're add the beginning of the list.
 void remove()
          Not supported in the base implementation.
 void reset()
          Re-initialize this RowIterator to its initial state (positioned just before the first Rowin the list).
 void set(Row row)
          Not supported in the base implementation.
 int size()
          Retunrs the current size of the underlaying row collection
 java.lang.String toString()
           
 
Methods inherited from class org.axiondb.engine.rowiterators.BaseRowIterator
first, isEmpty, peekNext, peekPrevious
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface org.axiondb.RowIterator
first, isEmpty, peekNext, peekPrevious
 

Constructor Detail

ChainedRowIterator

public ChainedRowIterator()
Method Detail

add

public void add(Row row)
         throws AxionException
Description copied from class: BaseRowIterator
Not supported in the base implementation.

Specified by:
add in interface RowIterator
Overrides:
add in class BaseRowIterator
Throws:
AxionException

addRowIterator

public void addRowIterator(RowIterator iter)

current

public Row current()
Description copied from interface: RowIterator
Returns the last Rowreturned by me (by RowIterator.next(),RowIterator.previous(), RowIterator.first(),RowIterator.last(), etc.).

Specified by:
current in interface RowIterator
Specified by:
current in class BaseRowIterator

currentIndex

public int currentIndex()
Description copied from interface: RowIterator
Returns the index of the RowIterator.current()row, if any.

Specified by:
currentIndex in interface RowIterator
Specified by:
currentIndex in class BaseRowIterator

hasCurrent

public boolean hasCurrent()
Description copied from interface: RowIterator
Returns true if I have a current Row. (In other words, returns true iff RowIterator.current()would return a Rowrather than throwing an exception.)

Specified by:
hasCurrent in interface RowIterator
Specified by:
hasCurrent in class BaseRowIterator

hasNext

public boolean hasNext()
Description copied from interface: RowIterator
Returns true if I have more Rows when traversing the list in the forward direction. (In other words, returns true iff RowIterator.next()would return a Rowrather than throwing an exception.)

Specified by:
hasNext in interface RowIterator
Specified by:
hasNext in class BaseRowIterator

hasPrevious

public boolean hasPrevious()
Description copied from interface: RowIterator
Returns true if I have more Rows when traversing the list in the reverse direction. (In other words, returns true iff RowIterator.previous()would return a Rowrather than throwing an exception.)

Specified by:
hasPrevious in interface RowIterator
Specified by:
hasPrevious in class BaseRowIterator

last

public Row last()
         throws AxionException
Description copied from interface: RowIterator
Returns the last Rowin the list, positioning the cursor to just after the last Rowin the list. (In other words, after last is called both RowIterator.previous()and RowIterator.current()will return the last row in the list.)

Specified by:
last in interface RowIterator
Overrides:
last in class BaseRowIterator
Throws:
AxionException - when a problem occurs accessing the Row

next

public Row next()
         throws AxionException
Description copied from interface: RowIterator
Returns the next Rowin the list, or throws NoSuchElementExceptionif no next Row exists.

Specified by:
next in interface RowIterator
Specified by:
next in class BaseRowIterator
Throws:
AxionException - when a problem occurs accessing the Row

next

public int next(int count)
         throws AxionException
Description copied from interface: RowIterator
Sets the current iterator position to currentIndex() + count; this will not set the current row, peekPrevious() may be used to return the current row. This will provide random access e.g one can postion the cursor before the desired row and then call next().

Specified by:
next in interface RowIterator
Overrides:
next in class BaseRowIterator
Throws:
AxionException

nextIndex

public int nextIndex()
Description copied from interface: RowIterator
Returns the index of the RowIterator.next()row, if any, or the number of elements is the iterator if we've reached the end.

Specified by:
nextIndex in interface RowIterator
Specified by:
nextIndex in class BaseRowIterator

previous

public Row previous()
             throws AxionException
Description copied from interface: RowIterator
Returns the previous Rowin the list, or throws NoSuchElementExceptionif no next Row exists.

Specified by:
previous in interface RowIterator
Specified by:
previous in class BaseRowIterator
Throws:
AxionException - when a problem occurs accessing the Row

previous

public int previous(int count)
             throws AxionException
Description copied from interface: RowIterator
Sets the current iterator position to currentIndex() - count; this will not set the current row, peekNext() may be used to return the current row. This will provide random access e.g one can postion the cursor after the desired row and then call previous().

Specified by:
previous in interface RowIterator
Overrides:
previous in class BaseRowIterator
Throws:
AxionException

previousIndex

public int previousIndex()
Description copied from interface: RowIterator
Returns the index of the RowIterator.previous()row, if any, or -1 if we're add the beginning of the list.

Specified by:
previousIndex in interface RowIterator
Specified by:
previousIndex in class BaseRowIterator

remove

public void remove()
            throws AxionException
Description copied from class: BaseRowIterator
Not supported in the base implementation.

Specified by:
remove in interface RowIterator
Overrides:
remove in class BaseRowIterator
Throws:
AxionException

reset

public void reset()
           throws AxionException
Description copied from interface: RowIterator
Re-initialize this RowIterator to its initial state (positioned just before the first Rowin the list).

Specified by:
reset in interface RowIterator
Specified by:
reset in class BaseRowIterator
Throws:
AxionException

set

public void set(Row row)
         throws AxionException
Description copied from class: BaseRowIterator
Not supported in the base implementation.

Specified by:
set in interface RowIterator
Overrides:
set in class BaseRowIterator
Throws:
AxionException

size

public int size()
         throws AxionException
Description copied from interface: RowIterator
Retunrs the current size of the underlaying row collection

Specified by:
size in interface RowIterator
Overrides:
size in class BaseRowIterator
Throws:
AxionException

toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object