com.goldencode.p2j.persist

Class ForwardResults

java.lang.Object

com.goldencode.p2j.persist.ForwardResults

All Implemented Interfaces:

Results

final class ForwardResults
extends java.lang.Object
implements Results

A simple, forward only implementation of the Results interface, which offers a thin layer around the internal, ScrollableResults object provided by the query.

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	closed Track closed state of the results.
private boolean	hasResults Flag to check if the result set is empty
private boolean	isAfterLast Flag to check if the cursor is after last row
private static CentralLogger	LOG Logger
private Persistence	persistence Persistence object which provided the underlying ScrollableResults
private Persistence.Context	persistenceContext The Persistence context.
private ScrollableResults<java.lang.Object>	results Scrollable result set; primary keys or Records
private int	rowNumber Cache the row number

Constructor Summary

Constructors

Constructor and Description
ForwardResults(Persistence persistence, ScrollableResults<java.lang.Object> results) Construct an instance of this object from a scrollable result set provided by query execution.

Method Summary

Modifier and Type	Method and Description
void	cleanup() Close the wrapped ScrollableResults object.
boolean	first() Move cursor to the first result row only if the cursor is behind it.
java.lang.Object[]	get() Get the array of objects at the current result row.
java.lang.Object	get(int column) Get the object at the current result row, at the specified column.
java.lang.Long	getID(int column) Get the primary key ID at the current result row, at the specified column.
int	getRowNumber() Get the row number currently under the cursor.
boolean	isFirst() Is the cursor on the first row in the result set?
boolean	isLast() Is the cursor on the last row in the result set?
boolean	last() Move cursor to the last result row.
boolean	next() Move cursor to the next result row.
boolean	previous() Should move cursor to the previous result row, but it cannot be done in FORWARD_ONLY mode.
void	reset() Should reset the cursor to its natural starting position, before the first result row, but it cannot be done in FORWARD_ONLY mode.
boolean	scroll(int rows) Scroll the cursor ahead by the specified number of rows.
void	sessionClosing() Invoked when the current Hibernate session is about to close.
boolean	setRowNumber(int row) Set the cursor at the row number.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.goldencode.p2j.persist.Results

addRow, deleteRow, get, getNumberOfLoadedRows, isAutoFetch, isResultSetCached

Field Detail

LOG

private static final CentralLogger LOG

Logger

results

private final ScrollableResults<java.lang.Object> results

Scrollable result set; primary keys or Records

persistence

private final Persistence persistence

Persistence object which provided the underlying ScrollableResults

persistenceContext

private final Persistence.Context persistenceContext

The Persistence context. Only used at cleanup time when the getter is not accessible any more.

closed

private boolean closed

Track closed state of the results.

hasResults

private boolean hasResults

Flag to check if the result set is empty

isAfterLast

private boolean isAfterLast

Flag to check if the cursor is after last row

rowNumber

private int rowNumber

Cache the row number

Constructor Detail

ForwardResults

ForwardResults(Persistence persistence,
               ScrollableResults<java.lang.Object> results)
        throws PersistenceException

Construct an instance of this object from a scrollable result set provided by query execution.

Parameters:

persistence - The associated persistence service object.

results - Scrollable result set generated by the query.

Throws:

PersistenceException

Method Detail

first

public boolean first()

Move cursor to the first result row only if the cursor is behind it.

Specified by:

first in interface Results

Returns:

true if the cursor is already first or behind it.

last

public boolean last()

Move cursor to the last result row.

Specified by:

last in interface Results

Returns:

true if there are any results.

next

public boolean next()

Move cursor to the next result row.

Specified by:

next in interface Results

Returns:

true if there is a result under the cursor.

previous

public boolean previous()

Should move cursor to the previous result row, but it cannot be done in FORWARD_ONLY mode.

Specified by:

previous in interface Results

Returns:

false .

isFirst

public boolean isFirst()

Is the cursor on the first row in the result set?

Specified by:

isFirst in interface Results

Returns:

true if the cursor is on the first row.

isLast

public boolean isLast()

Is the cursor on the last row in the result set?

Specified by:

isLast in interface Results

Returns:

true if the cursor is on the last row.

get

public java.lang.Object[] get()

Get the array of objects at the current result row.

Specified by:

get in interface Results

Returns:

Object array or null.

get

public java.lang.Object get(int column)

Get the object at the current result row, at the specified column.

Specified by:

get in interface Results

Parameters:

column - Zero-based index column of the desired object.

Returns:

Object at column or null.

getID

public java.lang.Long getID(int column)

Get the primary key ID at the current result row, at the specified column.

Specified by:

getID in interface Results

Parameters:

column - Zero-based index column of the desired ID.

Returns:

ID of the record or null.

getRowNumber

public int getRowNumber()

Get the row number currently under the cursor.

Specified by:

getRowNumber in interface Results

Returns:

Zero-based index of the current row, or -1 if the cursor is not currently on a result.

setRowNumber

public boolean setRowNumber(int row)

Set the cursor at the row number.

Specified by:

setRowNumber in interface Results

Parameters:

row - Zero-based index of the row to be set as the current row.

Returns:

true if the row number is after the current position and before last; else false.

scroll

public boolean scroll(int rows)

Scroll the cursor ahead by the specified number of rows.

Specified by:

scroll in interface Results

Parameters:

rows - Number of rows to jump ahead or back.

Returns:

true if there is a row at the new location; else false.

reset

public void reset()

Should reset the cursor to its natural starting position, before the first result row, but it cannot be done in FORWARD_ONLY mode.

Specified by:

reset in interface Results

sessionClosing

public void sessionClosing()

Invoked when the current Hibernate session is about to close. Gives the implementation an opportunity to perform appropriate processing in response to this event.

Specified by:

sessionClosing in interface Results

cleanup

public void cleanup()

Close the wrapped ScrollableResults object.

Specified by:

cleanup in interface Results