org.exolab.jms.persistence
Class Messages

java.lang.Object
  |
  +--org.exolab.jms.persistence.Messages

public class Messages

extends java.lang.Object

This class manages the persistence of message objects.

Version:

$Revision: 1.3 $ $Date: 2005/06/09 14:39:52 $

Author:

Tim Anderson

Constructor Summary

protected

Messages() Default constructor does nothing at the moment.

Method Summary

void	add(java.sql.Connection connection, MessageImpl message) Add a message to the database, in the context of the specified transaction and connection.
void	close() Reset the instance.
MessageImpl	deserialize(byte[] blob) Set the message from a serialized blob
MessageImpl	get(java.sql.Connection connection, java.lang.String messageId) Return the message identified by the message Id
java.util.HashMap	getMessageIds(java.sql.Connection connection, long time, int hint) Retrieve the specified number of message ids from the database with a time greater than that specified.
java.util.Vector	getMessages(java.sql.Connection connection, java.lang.String destination, int priority, long time) Retrieve the next set of messages for the specified destination with an acceptance time greater or equal to that specified.
java.util.Vector	getNonExpiredMessages(java.sql.Connection connection, JmsDestination destination) Retrieve the message handle for all unexpired messages
java.util.Vector	getUnprocessedMessages(java.sql.Connection connection) Retrieve a list of unprocessed messages and return them to the client.
static Messages	initialise() Create an initialise the singleton istance of this class.
static Messages	instance() Returns a reference to the singleton instance.
void	remove(java.sql.Connection connection, java.lang.String messageId) Remove a message with the specified identity from the database
void	removeExpiredMessages(java.sql.Connection connection) Delete all expired messages and associated message handles.
int	removeMessages(java.sql.Connection connection, java.lang.String destination) Delete all messages for the given destination
byte[]	serialize(MessageImpl message) Get the message as a serialized blob
void	update(java.sql.Connection connection, MessageImpl message) Update the message state in the database.

Methods inherited from class java.lang.Object

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

Constructor Detail

Messages

protected Messages()

Default constructor does nothing at the moment.

Method Detail

instance

public static Messages instance()

Returns a reference to the singleton instance.

Note that initialise() must have been invoked first for this to return a valid instance.

Returns:

Messages the singleton instance

initialise

public static Messages initialise()

Create an initialise the singleton istance of this class.

Returns:

Messages the singleton instance

add

public void add(java.sql.Connection connection,
                MessageImpl message)
         throws PersistenceException

Add a message to the database, in the context of the specified transaction and connection.

Parameters:

connection - - execute on this connection

message - - the message to add

Throws:

PersistenceException - - an sql related error

update

public void update(java.sql.Connection connection,
                   MessageImpl message)
            throws PersistenceException

Update the message state in the database. This will be called to set the message state to processed by the provider

Parameters:

connection - - execute on this connection

message - - the message to update

Throws:

PersistenceException - - an sql related error

remove

public void remove(java.sql.Connection connection,
                   java.lang.String messageId)
            throws PersistenceException

Remove a message with the specified identity from the database

Parameters:

connection - - execute on this connection

messageId - - the message id of the message to remove

Throws:

PersistenceException - - an sql related error

get

public MessageImpl get(java.sql.Connection connection,
                       java.lang.String messageId)
                throws PersistenceException

Return the message identified by the message Id

Parameters:

connection - - execute on this connection

messageId - - id of message to retrieve

Returns:

MessageImpl - the associated message

Throws:

PersistenceException - - an sql related error

removeMessages

public int removeMessages(java.sql.Connection connection,
                          java.lang.String destination)
                   throws PersistenceException

Delete all messages for the given destination

Parameters:

connection - - execute on this connection

destination - the destination to remove messages for

Returns:

int - the number of messages purged

Throws:

PersistenceException - - an sql related error

getMessages

public java.util.Vector getMessages(java.sql.Connection connection,
                                    java.lang.String destination,
                                    int priority,
                                    long time)
                             throws PersistenceException

Retrieve the next set of messages for the specified destination with an acceptance time greater or equal to that specified. It will retrieve around 200 or so messages depending on what is available.

Parameters:

connection - - execute on this connection

destination - - the destination

priority - - the priority of the messages

time - - with timestamp greater or equal to this

Returns:

Vector - one or more MessageImpl objects

Throws:

PersistenceException - - if an SQL error occurs

getMessageIds

public java.util.HashMap getMessageIds(java.sql.Connection connection,
                                       long time,
                                       int hint)
                                throws PersistenceException

Retrieve the specified number of message ids from the database with a time greater than that specified. The number of items to retrieve is only a hint and does not reflect the number of messages actually returned.

Parameters:

connection - - execute on this connection

time - - with timestamp greater than

hint - - an indication of the number of messages to return.

Returns:

a map of messageId Strings to their creation time

Throws:

PersistenceException - - if an SQL error occurs

getUnprocessedMessages

public java.util.Vector getUnprocessedMessages(java.sql.Connection connection)
                                        throws PersistenceException

Retrieve a list of unprocessed messages and return them to the client. An unprocessed message has been accepted by the system but not processed.

Parameters:

connection - - execute on this connection

Returns:

Vector - one or more MessageImpl objects

Throws:

PersistenceException - - if an SQL error occurs

getNonExpiredMessages

public java.util.Vector getNonExpiredMessages(java.sql.Connection connection,
                                              JmsDestination destination)
                                       throws PersistenceException

Retrieve the message handle for all unexpired messages

Parameters:

connection - - execute on this connection

destination - - the destination in question

Returns:

Vector - collection of PersistentMessageHandle objects

Throws:

PersistenceException - - sql releated exception

removeExpiredMessages

public void removeExpiredMessages(java.sql.Connection connection)
                           throws PersistenceException

Delete all expired messages and associated message handles.

Parameters:

connection - - execute on this connection

Throws:

PersistenceException - - if an SQL error occurs

close

public void close()

Reset the instance. We need to deprecate this method since this class does not contain state information

serialize

public byte[] serialize(MessageImpl message)
                 throws PersistenceException

Get the message as a serialized blob

Parameters:

message - the message to serialize

Returns:

byte[] the serialized message

deserialize

public MessageImpl deserialize(byte[] blob)
                        throws PersistenceException

Set the message from a serialized blob

Parameters:

blob - the serialized message

Returns:

the re-constructed message