guarana.toolkit.task.transformers
Class Splitter

java.lang.Object
  extended by guarana.util.observer.smart.SmartObservable
      extended by guarana.framework.task.Task
          extended by guarana.toolkit.task.transformers.Transformer
              extended by guarana.toolkit.task.transformers.Splitter
All Implemented Interfaces:
ISource, guarana.util.observer.smart.ISmartObserver

public abstract class Splitter
extends Transformer

Splits an inbound message into two or more outbound messages and puts them in a single slot. The CORRELATION_ID inside its header receives the MESSAGE_ID from the parent message. Each split message also receives a SEQUENCE_NUMBER and a SEQUENCE_SIZE to identify how many messages were split from the input message. All header from the inbound message is kept to the outbound message(s). Outbound messages have a new MESSAGE_ID and the inbound message as its parent.

Graphical notation:


This is an Integration Pattern implementation

Problem: How can we process a message if it contains multiple elements, each of which may have to be processed in a different way?

Solution: Use a Splitter to break out the composite message into a series of individual messages, each containing data related to one item.

Details:

Since:
Guaranį SDK 1.0.0
Author:
Rafael Z. Frantz
See Also:
Splitter pattern by Gregor Hohpe and Bobby Woolf for more details.

Field Summary
 
Fields inherited from class guarana.framework.task.Task
input, output
 
Constructor Summary
Splitter(String name)
          Constructs a new splitter task with a given name.
Splitter(String name, int numberOfInputs, int numberOfOutputs)
          Constructs a new splitter task.
 
Method Summary
abstract  void doWork(Exchange exchange)
          This method implements the business logic of this task.
 void execute()
          This method executes the business logic of this task.
 void update(guarana.util.observer.smart.SmartObservable slot, Object arg)
          This method is automatically called by the observable slot to notify the slot has received a message.
 
Methods inherited from class guarana.framework.task.Task
getName, getTriggerInterval, isTriggerTask, setName, setTriggerInterval
 
Methods inherited from class guarana.util.observer.smart.SmartObservable
addSmartObserver, containsSmartObserver, containsSmartObserver, countSmartObservers, deleteSmartObserver, deleteSmartObservers, hasChanged, notifySmartObservers, notifySmartObservers
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Splitter

public Splitter(String name)
Constructs a new splitter task with a given name.

Parameters:
name - The name of the splitter task.

Splitter

public Splitter(String name,
                int numberOfInputs,
                int numberOfOutputs)
Constructs a new splitter task.

Parameters:
name - The name of this task.
numberOfInputs - The number of input gateways this task must have.
numberOfOutputs - The number of output gateways this task must have.
Method Detail

execute

public void execute()
             throws TaskExecutionException
This method executes the business logic of this task. It is automatically invoked by workers.

Overrides:
execute in class Task
Throws:
TaskExecutionException - to report any exception that has occurred during the execution of this method.
See Also:
TaskExecutionException

doWork

public abstract void doWork(Exchange exchange)
                     throws TaskExecutionException
This method implements the business logic of this task.
Splits an inbound message into two or more outbound messages. The policy to split, as well as its implementation must be provided by the used in this method.

Overrides:
doWork in class Task
Parameters:
exchange - An exchange object that holds the inbound messages of this task.
Throws:
TaskExecutionException - to report any exception that has occurred during the execution of this method.

update

public void update(guarana.util.observer.smart.SmartObservable slot,
                   Object arg)
This method is automatically called by the observable slot to notify the slot has received a message. For all those tasks that can execute with one or more messages in its input slots, this method will add the task to the executable task reporter, so it can be executed. In this case the task execution will consume messages from all input slots.
Please, do not call this method by yourself. Overrides the implementation at Task for performance reasons.

Specified by:
update in interface guarana.util.observer.smart.ISmartObserver
Overrides:
update in class Task
Parameters:
slot - The Slot associated with this task.
arg - THIS PARAMETHER IS NOT USED.


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