org.camunda.bpm.engine.impl
Class MessageCorrelationBuilderImpl

java.lang.Object
  org.camunda.bpm.engine.impl.MessageCorrelationBuilderImpl

All Implemented Interfaces:

MessageCorrelationBuilder

public class MessageCorrelationBuilderImpl
extends Object
implements MessageCorrelationBuilder

Author:

Daniel Meyer

Field Summary

protected String	businessKey
protected CommandContext	commandContext
protected CommandExecutor	commandExecutor
protected Map<String,Object>	correlationProcessInstanceVariables
protected boolean	isExclusiveCorrelation
protected String	messageName
protected Map<String,Object>	payloadProcessInstanceVariables
protected String	processInstanceId

Constructor Summary

MessageCorrelationBuilderImpl(CommandContext commandContext, String messageName)

MessageCorrelationBuilderImpl(CommandExecutor commandExecutor, String messageName)

Method Summary

void	correlate() Executes the message correlation.
void	correlateAll() Executes the message correlation for multiple messages.
void	correlateExclusively() Behaves like MessageCorrelationBuilder.correlate(), however uses pessimistic locking for correlating a waiting execution, meaning that two threads correlating a message to the same execution in parallel do not end up continuing the process in parallel until the next wait state is reached
protected void	ensurePayloadProcessInstanceVariablesInitialized()
String	getBusinessKey()
CommandContext	getCommandContext()
CommandExecutor	getCommandExecutor()
Map<String,Object>	getCorrelationProcessInstanceVariables()
String	getMessageName()
Map<String,Object>	getPayloadProcessInstanceVariables()
String	getProcessInstanceId()
boolean	isExclusiveCorrelation()
MessageCorrelationBuilder	processInstanceBusinessKey(String businessKey) Correlate the message such that the process instance has a business with the given name and value.
MessageCorrelationBuilder	processInstanceId(String id) Correlate the message such that a process instance with the given id is selected.
MessageCorrelationBuilder	processInstanceVariableEquals(String variableName, Object variableValue) Correlate the message such that the process instance has a variable with the given name and value.
MessageCorrelationBuilder	setVariable(String variableName, Object variableValue) Pass a variable to the execution waiting on the message.
MessageCorrelationBuilder	setVariables(Map<String,Object> variables) Pass a map of variables to the execution waiting on the message.

Methods inherited from class java.lang.Object

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

Field Detail

commandExecutor

protected CommandExecutor commandExecutor

commandContext

protected CommandContext commandContext

isExclusiveCorrelation

protected boolean isExclusiveCorrelation

messageName

protected String messageName

businessKey

protected String businessKey

processInstanceId

protected String processInstanceId

correlationProcessInstanceVariables

protected Map<String,Object> correlationProcessInstanceVariables

payloadProcessInstanceVariables

protected Map<String,Object> payloadProcessInstanceVariables

Constructor Detail

MessageCorrelationBuilderImpl

public MessageCorrelationBuilderImpl(CommandExecutor commandExecutor,
                                     String messageName)

MessageCorrelationBuilderImpl

public MessageCorrelationBuilderImpl(CommandContext commandContext,
                                     String messageName)

Method Detail

processInstanceBusinessKey

public MessageCorrelationBuilder processInstanceBusinessKey(String businessKey)

Description copied from interface: MessageCorrelationBuilder

Correlate the message such that the process instance has a business with the given name and value.

Specified by:

processInstanceBusinessKey in interface MessageCorrelationBuilder

Parameters:

businessKey - the businessKey to correlate on.

Returns:

the builder

processInstanceVariableEquals

public MessageCorrelationBuilder processInstanceVariableEquals(String variableName,
                                                               Object variableValue)

Description copied from interface: MessageCorrelationBuilder

Correlate the message such that the process instance has a variable with the given name and value.

Specified by:

processInstanceVariableEquals in interface MessageCorrelationBuilder

Parameters:

variableName - the name of the process instance variable to correlate on.

variableValue - the value of the process instance variable to correlate on.

Returns:

the builder

processInstanceId

public MessageCorrelationBuilder processInstanceId(String id)

Description copied from interface: MessageCorrelationBuilder

Correlate the message such that a process instance with the given id is selected.

Specified by:

processInstanceId in interface MessageCorrelationBuilder

Parameters:

id - the id of the process instance to correlate on.

Returns:

the builder

setVariable

public MessageCorrelationBuilder setVariable(String variableName,
                                             Object variableValue)

Description copied from interface: MessageCorrelationBuilder

Pass a variable to the execution waiting on the message. Use this method for passing the message's payload.

Invoking this method multiple times allows passing multiple variables.

Specified by:

setVariable in interface MessageCorrelationBuilder

Parameters:

variableName - the name of the variable to set

variableValue - the value of the variable to set

Returns:

the builder

setVariables

public MessageCorrelationBuilder setVariables(Map<String,Object> variables)

Description copied from interface: MessageCorrelationBuilder

Pass a map of variables to the execution waiting on the message. Use this method for passing the message's payload

Specified by:

setVariables in interface MessageCorrelationBuilder

Parameters:

variables - the map of variables

Returns:

the builder

ensurePayloadProcessInstanceVariablesInitialized

protected void ensurePayloadProcessInstanceVariablesInitialized()

correlate

public void correlate()

Description copied from interface: MessageCorrelationBuilder

Executes the message correlation.

This will result in either:

• Exactly one waiting execution is notified to continue. The notification is performed synchronously.
• Exactly one Process Instance is started in case the message name matches a message start event of a process. The instantiation is performed synchronously.
• MismatchingMessageCorrelationException is thrown. This means that either too many executions match the correlation or that no execution matches the correlation.

Specified by:

correlate in interface MessageCorrelationBuilder

correlateExclusively

public void correlateExclusively()

Description copied from interface: MessageCorrelationBuilder

Behaves like MessageCorrelationBuilder.correlate(), however uses pessimistic locking for correlating a waiting execution, meaning that two threads correlating a message to the same execution in parallel do not end up continuing the process in parallel until the next wait state is reached

CAUTION: Wherever there are pessimistic locks, there is a potential for deadlocks to occur. This can either happen when multiple messages are correlated in parallel, but also with other race conditions such as a message boundary event on a user task. The process engine is not able to detect such a potential. In consequence, the user of this API should investigate this potential in his/her use case and implement countermeasures if needed.

A less error-prone alternative to this method is to set appropriate async boundaries in the process model such that parallel message correlation is solved by optimistic locking.

Specified by:

correlateExclusively in interface MessageCorrelationBuilder

correlateAll

public void correlateAll()

Description copied from interface: MessageCorrelationBuilder

Executes the message correlation for multiple messages.

This will result in any number of the following:

• Any number of waiting executions are notified to continue. The notification is performed synchronously.
• Zero or one Process Instance is started in case the message name matches a message start event of a process. The instantiation is performed synchronously.

Specified by:

correlateAll in interface MessageCorrelationBuilder

getCommandExecutor

public CommandExecutor getCommandExecutor()

getCommandContext

public CommandContext getCommandContext()

getMessageName

public String getMessageName()

getBusinessKey

public String getBusinessKey()

getProcessInstanceId

public String getProcessInstanceId()

getCorrelationProcessInstanceVariables

public Map<String,Object> getCorrelationProcessInstanceVariables()

getPayloadProcessInstanceVariables

public Map<String,Object> getPayloadProcessInstanceVariables()

isExclusiveCorrelation

public boolean isExclusiveCorrelation()