Message Class

A message is the unit that is enqueued dequeued. A Message object holds both its content, or payload, and its properties. This class provides methods to get and set message properties.

Table 12-24 Enumerated Values Used by Message Class

Attribute	Options
MessageState	MSG_WAITING indicates that the message delay time has not been reached `MSG_READY` indicates that the message is ready to be processed `MSG_PROCESSED` indicates that the message has been processed, and is being retained `MSG_EXPIRED` indicates that the message has been moced to the exception queue.
PayloadType	`RAW` ANYDATA `OBJECT`

Table 12-25 Summary of Message Methods

Method	Summary
Message()	`Message` class constructor.
getAnyData()	Retrieves `AnyData` payload of the message.
getAttemptsToDequeue()	Retrieves the number of attempts made to dequeue the message.
getBytes()	Retrieves `Bytes` payload of the message.
getCorrelationId()	Retrieves the identification string.
getDelay()	Retrieves delay with which message was enqueued.
getExceptionQueueName()	Retrieves name of queue to which `Message` is moved when it cannot be processed.
getExpiration()	Retrieves the expiration of the message.
getMessageEnqueuedTime()	Retrieves time at which message was enqueued.
getMessageState()	Retrieves state of the message at time of enqueuing.
getObject()	Retrieves object payload of the message.
getOriginalMessageId()	Retrieves the Id of the message that generated this message on the last queue.
getPayloadType()	Retrieves the type of the payload..
getPriority()	Retrieves the priority of the message.
getSenderId()	Retrieves the agent who send the `Message`.
isNull()	Tests whether the `Message` object is `NULL`.
operator=()	Assignment operator for `Message`.
setAnyData()	Specifies `AnyData` payload of the message.
setBytes()	Specifies `Bytes` payload of the message.
setCorrelationId()	Specifies the identification string.
setDelay()	Specifies the number of seconds to delay the enqueued `Message`.
setExceptionQueueName()	Specifies the name of the queue to which the `Message` object will be moved if it cannot be precessed.
setExpiration()	Specifies the duration of time that `Message` can be dequeued before it expires.
setNull()	Sets the `Message` object to `NULL`.
setObject()	Specifies object payload of the message.
setOriginalMessageId()	Specifies id of last queue that generated the `Message`.
setPriority()	Specifies priority of the `Message` object.
setRecipientList()	Specifies the list of agents for whom the message is intended.
setSenderId()	Specifies the sender of the `Message`.

Message()

Message class constructor.

Syntax	Description
Message( const Environment *env);	Creates a `Message` object within the specified `Environment`.
Message( const Message& mes);	Copy constructor.

Parameter	Description
env	The environment of the `Message`.
mes	The original `Message`..

getAnyData()

Retrieves the AnyData payload of the Message.

Syntax

AnyData getAnyData() const;

getAttemptsToDequeue()

Retrieves the number of attempts made to dequeue the message. This property cannot be retrieved while enqueuing.

Syntax

int getAttemptsToDequeue() const;

getBytes()

Retrieves Bytes payload of the Message.

Syntax

Bytes getBytes() const;

getCorrelationId()

Retrieves the identification string.

Syntax

string getCorrelationId() const;

getDelay()

Retrieves the delay (in seconds) with which the Message was enqueued.

Syntax

int getDelay() const;

getExceptionQueueName()

Retrieves the name of the queue to which the Message is moved, in cases when the Message cannot be processed successfully.

Syntax

string getExceptionQueueName() const;

getExpiration()

Retrieves the expiration time of the Message (in seconds). This is the duration for which the message is available for dequeuing.

Syntax

int getExpiration() const;

getMessageEnqueuedTime()

Retrieves the time at which the message was enqueued, in Date format. This value is determined by the system, and cannot be set by the user.

Syntax

Date getMessageEnqueuedTime() const;

getMessageState()

Retrieves the state of the message at the time of enqueuing. This parameter cannot be set an enqueuing time. MessageState is defined in Table 12-24.

Syntax

MessageState getMessageState() const;

getObject()

Retrieves object payload of the Message.

Syntax

PObject* getObject();

getOriginalMessageId()

Retrieves the original message Id. When a message is propogated from one queue to another, gets the ID to the last queue that generated this message.

Syntax

Bytes getOriginalMessageId() const;

getPayloadType()

Retrieves the type of the payload, as defined for PayloadType in Table 12-24.

Syntax

PayloadType getPayloadType( ) const;

getPriority()

Retrieves the priority of the Message.

Syntax

int getPriority() const;

getSenderId()

Retrieves the agent who send the Message.

Syntax

Agent getSenderId() const;

isNull()

Tests whether the Message object is NULL. If the Message object is NULL, then TRUE is returned; otherwise, FALSE is returned.

Syntax

bool isNull() const;

operator=()

Assignment operator for Message.

void operator=(
   const Message& mes);

Parameter	Description
mes	Original message..

setAnyData()

Specifies AnyData payload of the Message.

Syntax

void setAnyData(
   const AnyData& anydata);

Parameter	Description
anydata	Data content of the `Message`.

setBytes()

Specifies Bytes payload of the Message.

Syntax

void setBytes(
   const Bytes& bytes);

Parameter	Description
bytes	Data content of the `Message`.

setCorrelationId()

Specifies the identification string. This parameter is set at enqueuing time by the Producer. Messages can be dequeued with this id. The id can contain wildcard characters.

Syntax

void setCorrelationId(
   const string& id);

Parameter	Description
id	The id; upper limit of `128` bytes.

setDelay()

Specifies the time (in seconds) to delay the enqueued Message. After the delay ends, the Message is available for dequeuing.

Note:

Dequeuing by msgid overrides the delay specification. A Message enqueued with delay will be in the WAITING state. Delay is set by the producer of the Message.

Syntax

void setDelay(
   int delay);

Parameter	Description
delay	The delay.

setExceptionQueueName()

Specifies the name of the queue to which the Message object will be moved if it cannot be processed successfully. The queue name must be valid.

Note:

If the exception queue does not exist at the time of the move, the Message will be moved to the default exception queue associated with the queue table; a warning will be logged in the alert file.
If the default exception queue is used, the parameter will return a NULL value at enqueuing time; the attribute must refer to a valid queue name.

Syntax

void setExceptionQueueName(
   const string& queue);

Parameter	Description
queue	The name of the exception queue.

setExpiration()

Specifies the duration time (in seconds) that the Message object is available for dequeuing. A Message expires after this time.

Syntax

void setExpiration(
   int exp);

Parameter	Description
exp	The duration of expiration.

setNull()

Sets the Message object to NULL. Before the Connection is destroyed by the terminateConnection() call of the Environment Class, all Message objects need to be set to NULL.

Syntax

void setNull();

setObject()

Specifies object payload of the Message.

Syntax

void setObject(
   PObject& pobj);

Parameter	Description
pobj	Content of the data

setOriginalMessageId()

Sets the Id of the last queue that generated the message, when a message is propogated from one queue to another.

Syntax

void setOriginalMessageId(
   const Bytes& queue);

Parameter	Description
queue	The last queue.

setPriority()

Specifies the priority of the Message object. This property is set during enqueuing time, and can be negative. Default is 0.

Syntax

void setPriority(
   int priority);

Parameter	Description
priority	The priority of the `Message`.

setRecipientList()

Specifies the list of Agents for whom the Message is intended. These recipients are not identical to subscribers of the queue. The property is set during enqueuing. All Agents in the list must be valid. The recipient list will override the default subscriber list.

Syntax

void setRecipientList(
   vector<Agent>& agentList);

Parameter	Description
agentList	The list of `Agent`s.

setSenderId()

Specifies the sender of the Message.

Syntax

void setSenderId(
   const Agent& sender);

Parameter	Description
sender	Sender id.