Module org.tentackle.persistence

Package org.tentackle.persist.rmi

Class RemoteResultSetCursorImpl<T extends PersistentDomainObject<T>>

java.lang.Object

org.tentackle.dbms.rmi.RemoteDelegateImpl<T>

org.tentackle.persist.rmi.RemoteResultSetCursorImpl<T>

Type Parameters:

T - the object type

All Implemented Interfaces:

Remote, RemoteDelegate, RemoteResultSetCursor<T>

public class RemoteResultSetCursorImpl<T extends PersistentDomainObject<T>>
extends RemoteDelegateImpl<T>
implements RemoteResultSetCursor<T>

Remote delegate implementation for ResultSetCursor.

Author:

harald

Constructor Summary

Constructors

Constructor	Description
RemoteResultSetCursorImpl(RemoteDbSessionImpl session, Class<T> clazz)	Creates a remote cursor delegate.

Method Summary

Modifier and Type	Method	Description
int	afterLast()	Positions the cursor after the last row. Works even for empty cursors.
void	beforeFirst()	Positions the cursor before the first row. Works even for empty cursors.
void	close()	Closes the scrollable resource. The scrollable resource is opened in its constructor.
void	configureDelegate(Object... args)	Configures the delegate.
RemoteException	createException(Throwable t)
ResultSetCursor.FetchList<T>	fetch()	Fetches the next objects up to the fetchsize. This method is provided to minimize the number of roundtrips especially for remote cursors.
boolean	first()	Rewinds the cursor to the first row.
T	get()	Gets the data object of the current row.
ResultSetCursor<T>	getCursor()	Gets the local cursor.
int	getFetchDirection()	Gets the fetch direction.
int	getFetchSize()	Gets the fetchsize.
boolean	isAfterLast()	Checks whether the cursor is after the last row.
int	last()	Positions the cursor on the last row.
boolean	next()	Moves the cursor to the next row.
boolean	previous()	Moves the cursor to the previous row.
int	scroll(int rows)	Moves the cursor a given number of rows.
void	setCursor(ResultSetCursor<T> cursor)	Sets the local cursor.
void	setFetchDirection(int direction)	Sets the fetch direction.
void	setFetchSize(int rows)	Sets the fetchsize. This is the number of rows the cursor will fetch from the server in one batch.
int	setRow(int row)	Sets the cursor to a given row. Row numbers start at 1.
List<T>	toList()	Returns the objects of this cursor as a list.
String	toString()

Methods inherited from class org.tentackle.dbms.rmi.RemoteDelegateImpl

getServerSession, getServicedClass, getSession, initialize

Methods inherited from class java.lang.Object

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

Constructor Detail

RemoteResultSetCursorImpl

public RemoteResultSetCursorImpl(RemoteDbSessionImpl session,
                                 Class<T> clazz)

Creates a remote cursor delegate.

Parameters:

session - is the RMI session

clazz - is the subclass of DbObject

Method Detail

toString

public String toString()

Overrides:

toString in class RemoteDelegateImpl<T extends PersistentDomainObject<T>>

configureDelegate

public void configureDelegate(Object... args)

Configures the delegate.

Invoked from RemoteDbSessionImpl.createRemoteDelegateInstance(java.lang.Class<T>, java.lang.Class<I>, java.lang.Class<?>, java.lang.Class<?>, java.lang.Object...) by reflection.

Parameters:

args - the configuration paramaters

setCursor

public void setCursor(ResultSetCursor<T> cursor)

Sets the local cursor.

Parameters:

cursor - the cursor

getCursor

public ResultSetCursor<T> getCursor()

Gets the local cursor.

Returns:

the local cursor

afterLast

public int afterLast()
              throws RemoteException

Description copied from interface: RemoteResultSetCursor

Positions the cursor after the last row.
Works even for empty cursors.

Specified by:

afterLast in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

the current row

Throws:

RemoteException - if failed

beforeFirst

public void beforeFirst()
                 throws RemoteException

Description copied from interface: RemoteResultSetCursor

Positions the cursor before the first row.
Works even for empty cursors.

Specified by:

beforeFirst in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Throws:

RemoteException - if failed

close

public void close()
           throws RemoteException

Description copied from interface: RemoteResultSetCursor

Closes the scrollable resource.
The scrollable resource is opened in its constructor. Closing an already closed scrollable resource is allowed.

Specified by:

close in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Throws:

RemoteException - if failed

first

public boolean first()
              throws RemoteException

Description copied from interface: RemoteResultSetCursor

Rewinds the cursor to the first row.

Specified by:

first in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

true if rewound, false if cursor is empty

Throws:

RemoteException - if failed

get

public T get()
      throws RemoteException

Description copied from interface: RemoteResultSetCursor

Gets the data object of the current row.

Specified by:

get in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

the object, null if invalid row or no such object

Throws:

RemoteException - if failed

isAfterLast

public boolean isAfterLast()
                    throws RemoteException

Description copied from interface: RemoteResultSetCursor

Checks whether the cursor is after the last row.

Specified by:

isAfterLast in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

true if after last

Throws:

RemoteException - if failed

last

public int last()
         throws RemoteException

Description copied from interface: RemoteResultSetCursor

Positions the cursor on the last row.

Specified by:

last in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

the current row

Throws:

RemoteException - if failed

next

public boolean next()
             throws RemoteException

Description copied from interface: RemoteResultSetCursor

Moves the cursor to the next row. If there are no more rows the current row remains unchanged.

Specified by:

next in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

true if moved, false if no more rows

Throws:

RemoteException - if failed

previous

public boolean previous()
                 throws RemoteException

Description copied from interface: RemoteResultSetCursor

Moves the cursor to the previous row. If we are already at the beginning, the cursor remains unchanged.

Specified by:

previous in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

true if advanced, false if already at the beginning

Throws:

RemoteException - if failed

setRow

public int setRow(int row)
           throws RemoteException

Description copied from interface: RemoteResultSetCursor

Sets the cursor to a given row.
Row numbers start at 1.

Specified by:

setRow in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Parameters:

row - the row number (must be ≥ 0)

Returns:

the new row number

Throws:

RemoteException - if failed

scroll

public int scroll(int rows)
           throws RemoteException

Description copied from interface: RemoteResultSetCursor

Moves the cursor a given number of rows.

Specified by:

scroll in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Parameters:

rows - the number of rows to move, negative to move backwards

Returns:

the current row

Throws:

RemoteException - if failed

toList

public List<T> toList()
               throws RemoteException

Description copied from interface: RemoteResultSetCursor

Returns the objects of this cursor as a list.

Specified by:

toList in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

the list

Throws:

RemoteException - if failed

setFetchSize

public void setFetchSize(int rows)
                  throws RemoteException

Description copied from interface: RemoteResultSetCursor

Sets the fetchsize.
This is the number of rows the cursor will fetch from the server in one batch. A fetchsize of 0 means server default.

Specified by:

setFetchSize in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Parameters:

rows - the fetchsize

Throws:

RemoteException - if failed

getFetchSize

public int getFetchSize()
                 throws RemoteException

Description copied from interface: RemoteResultSetCursor

Gets the fetchsize.

Specified by:

getFetchSize in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

the fetchsize

Throws:

RemoteException - if failed

setFetchDirection

public void setFetchDirection(int direction)
                       throws RemoteException

Description copied from interface: RemoteResultSetCursor

Sets the fetch direction.

Specified by:

setFetchDirection in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Parameters:

direction - the direction, see ResultSet.setFetchDirection(int)

Throws:

RemoteException - if failed

getFetchDirection

public int getFetchDirection()
                      throws RemoteException

Description copied from interface: RemoteResultSetCursor

Gets the fetch direction.

Specified by:

getFetchDirection in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

the direction

Throws:

RemoteException - if failed

fetch

public ResultSetCursor.FetchList<T> fetch()
                                   throws RemoteException

Description copied from interface: RemoteResultSetCursor

Fetches the next objects up to the fetchsize.
This method is provided to minimize the number of roundtrips especially for remote cursors. The cursor is closed at the end of the cursor.

Specified by:

fetch in interface RemoteResultSetCursor<T extends PersistentDomainObject<T>>

Returns:

the list of objects, null if no more objects found

Throws:

RemoteException - if failed

createException

public RemoteException createException(Throwable t)

Overrides:

createException in class RemoteDelegateImpl<T extends PersistentDomainObject<T>>