Package de.digitalcollections.workflow.engine

Class Engine

java.lang.Object

de.digitalcollections.workflow.engine.Engine

public class Engine
extends Object

Run flows Flow for every message from the MessageBroker - usually several in parallel.

Constructor Summary

Constructors

Constructor	Description
Engine(MessageBroker messageBroker, Flow flow)	Creates a new Engine instance with concurrent workers.
Engine(MessageBroker messageBroker, Flow flow, int concurrentWorkers)	Creates a new Engine instance with a fixed number of concurrent workers.
Engine(MessageBroker messageBroker, Flow flow, int concurrentWorkers, ProcessReport processReport)	Creates a new Engine instance with a fixed number of concurrent workers.
Engine(MessageBroker messageBroker, Flow flow, ProcessReport processReport)	Creates a new Engine instance with a customized process report.

Method Summary

Modifier and Type	Method	Description
EngineStats	getStats()
void	start()	Starts processing messages until stop() is called.
void	stop()	Stops processing new messages or waiting for new messages to arrive.

Methods inherited from class java.lang.Object

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

Constructor Detail

Engine

public Engine(MessageBroker messageBroker,
              Flow flow)
       throws IOException

Creates a new Engine instance with concurrent workers.

Parameters:

messageBroker - the message broker to get messages from or send messages to

flow - the flow to execute agains every message

Throws:

IOException - if reading/writing to the message broker fails

Engine

public Engine(MessageBroker messageBroker,
              Flow flow,
              int concurrentWorkers)
       throws IOException

Creates a new Engine instance with a fixed number of concurrent workers.

Parameters:

messageBroker - the message broker to get messages from or send messages to

flow - the flow to execute agains every message

concurrentWorkers - the number of concurrent workers

Throws:

IOException - if reading/writing to the message broker fails

Engine

public Engine(MessageBroker messageBroker,
              Flow flow,
              ProcessReport processReport)
       throws IOException

Creates a new Engine instance with a customized process report.

Parameters:

messageBroker - the message broker to get messages from or send messages to

flow - the flow to execute agains every message

processReport - Reporting implementation

Throws:

IOException - if reading/writing to the message broker fails

Engine

public Engine(MessageBroker messageBroker,
              Flow flow,
              int concurrentWorkers,
              ProcessReport processReport)
       throws IOException

Creates a new Engine instance with a fixed number of concurrent workers.

Parameters:

messageBroker - the message broker to get messages from or send messages to

flow - the flow to execute agains every message

concurrentWorkers - the number of concurrent workers

processReport - Reporting implementation (or null, if DefaultProcessReport shall be used)

Throws:

IOException - if reading/writing to the message broker fails

Method Detail

start

public void start()

Starts processing messages until stop() is called. If there are no messages in the input queue, the engine waits for new messages to arrive.

stop

public void stop()

Stops processing new messages or waiting for new messages to arrive. This usually means that the application will shut down when the last worker finished.

getStats

public EngineStats getStats()

Returns:

statistics about the engine's state like active workers