Package de.digitalcollections.workflow.engine.messagebroker

Class MessageBrokerBuilder

java.lang.Object

de.digitalcollections.workflow.engine.messagebroker.MessageBrokerBuilder

public class MessageBrokerBuilder
extends Object

Builder to create an instance of the MessageBroker which manages the connection to RabbitMQ and all related configuration and setups like creating queues and exchanges.

Constructor Summary

Constructors

Constructor	Description
MessageBrokerBuilder()

Method Summary

Modifier and Type	Method	Description
MessageBrokerBuilder	addFailurePolicy(FailurePolicy failurePolicy)
MessageBroker	build()	Finally builds the MessageBroker as configured, up and running and connected it to RabbitMQ.
MessageBrokerBuilder	connectTo(String connectionStr)
MessageBrokerBuilder	connectTo(String host, int port)	Adds an RabbitMQ host to connect to.
MessageBrokerBuilder	deadLetterExchange(String deadLetterExchange)	Sets the AMQP dead letter exchange (optional, defaults to 'workflow.dlx').
MessageBrokerBuilder	deadLetterWait(int milliseconds)	Sets the time to wait for dead-lettered messages before these are returned to the queue.
MessageBrokerBuilder	exchange(String exchange)	Sets the AMQP exchange (optional, defaults to 'workflow').
MessageBrokerBuilder	jacksonModules(com.fasterxml.jackson.databind.Module... modules)	Registers Jackson Modules to use with the object mapper.
MessageBrokerBuilder	maxRetries(int number)	Sets the maximum number of attempts before a message is sent to the failed queue instead of the dead letter queue.
MessageBrokerBuilder	messageMapping(Class<? extends Message> messageClass, Class<?> messageMixin)	Sets a Jackson mixin for a custom message implementation.
MessageBrokerBuilder	password(String password)	Sets the RabbitMQ password for authentication.
MessageBrokerBuilder	readFrom(String... inputQueues)	The queues to read from.
MessageBrokerBuilder	username(String username)	Sets the RabbitMQ username for authentication.
MessageBrokerBuilder	virtualHost(String virtualHost)	Sets the internal RabbitMQ virtualHost (default is "\").
MessageBrokerBuilder	writeTo(String outputRoutingKey)

Methods inherited from class java.lang.Object

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

Constructor Detail

MessageBrokerBuilder

public MessageBrokerBuilder()

Method Detail

connectTo

public MessageBrokerBuilder connectTo(String host,
                                      int port)

Adds an RabbitMQ host to connect to. Default would be localhost with port 5672. To configure cluster access call this method once for each server.

Parameters:

host - The host to connect to.

port - The port to use for this connection

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

connectTo

public MessageBrokerBuilder connectTo(String connectionStr)

password

public MessageBrokerBuilder password(String password)

Sets the RabbitMQ password for authentication.

Parameters:

password - The password for authentication.

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

username

public MessageBrokerBuilder username(String username)

Sets the RabbitMQ username for authentication.

Parameters:

username - The username for authentication.

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

virtualHost

public MessageBrokerBuilder virtualHost(String virtualHost)

Sets the internal RabbitMQ virtualHost (default is "\").

Parameters:

virtualHost - The virtual host.

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

jacksonModules

public MessageBrokerBuilder jacksonModules(com.fasterxml.jackson.databind.Module... modules)

Registers Jackson Modules to use with the object mapper.

Parameters:

modules - The Jackson @Modules to register

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

deadLetterWait

public MessageBrokerBuilder deadLetterWait(int milliseconds)

Sets the time to wait for dead-lettered messages before these are returned to the queue.

Parameters:

milliseconds - The waiting time.

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

maxRetries

public MessageBrokerBuilder maxRetries(int number)

Sets the maximum number of attempts before a message is sent to the failed queue instead of the dead letter queue.

Parameters:

number - The maximum number of attempts to process a message.

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

messageMapping

public MessageBrokerBuilder messageMapping(Class<? extends Message> messageClass,
                                           Class<?> messageMixin)

Sets a Jackson mixin for a custom message implementation.

Parameters:

messageClass - The custom message implementation you want to use.

messageMixin - The mixin to serialize/deserialize this message.

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

exchange

public MessageBrokerBuilder exchange(String exchange)

Sets the AMQP exchange (optional, defaults to 'workflow'). If an exchange does not exist it will be created.

Parameters:

exchange - The regular exchange.

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

deadLetterExchange

public MessageBrokerBuilder deadLetterExchange(String deadLetterExchange)

Sets the AMQP dead letter exchange (optional, defaults to 'workflow.dlx'). If an exchange does not exist it will be created.

Parameters:

deadLetterExchange - The dead letter exchange.

Returns:

This MessageBrokerBuilder instance to chain configuration calls.

build

public MessageBroker build()
                    throws WorkflowSetupException

Finally builds the MessageBroker as configured, up and running and connected it to RabbitMQ.

Returns:

A new MessageBroker

Throws:

WorkflowSetupException - If connection to RabbitMQ fails.

readFrom

public MessageBrokerBuilder readFrom(String... inputQueues)

The queues to read from. All queues are considered in order. Only if a queue is empty, the next queue will be queried.

Parameters:

inputQueues - The queue names to read from.

Returns:

This builder for a fluent interface.

addFailurePolicy

public MessageBrokerBuilder addFailurePolicy(FailurePolicy failurePolicy)

writeTo

public MessageBrokerBuilder writeTo(String outputRoutingKey)