org.jbpm.pvm
Interface ExternalActivity

All Superinterfaces:

Activity, java.io.Serializable

public interface ExternalActivity
extends Activity

extends Activity for handling external triggers after a wait state.

Process languages will provide a set of these node implementations. But languages like jPDL even allow users to provide their own node behaviour with this interface.

Author:

Tom Baeyens

Field Summary

static java.util.Set<SignalDefinition>

DEFAULT_SIGNAL_SET

Method Summary

java.util.Set<SignalDefinition>	getSignals(Execution execution) the list of signals that this node behaviour can handle in signal(Execution, String, Map).
void	signal(Execution execution, java.lang.String signalName, java.util.Map<java.lang.String,java.lang.Object> parameters) handles an external trigger.

Methods inherited from interface org.jbpm.pvm.Activity

execute

Field Detail

DEFAULT_SIGNAL_SET

static final java.util.Set<SignalDefinition> DEFAULT_SIGNAL_SET

Method Detail

getSignals

java.util.Set<SignalDefinition> getSignals(Execution execution)
                                           throws java.lang.Exception

the list of signals that this node behaviour can handle in signal(Execution, String, Map).

This enables some form of reflection on a process execution.

For easy creation of signal definition sets, see the fluent builder interface of SignalDefinition.

If the returned list is null, it means that this functionality is unavailable. To indicate that only the default signal is available, DEFAULT_SIGNAL_SET can be used. Nodes can assume that the given execution is positioned in the node so they don't have to check that.

Throws:

java.lang.Exception - to indicate any kind of failure. Note that exceptions are considered non recoverable. After an Exception, the execution should not be used any more and if this is during a transaction, the transaction should be rolled back.

signal

void signal(Execution execution,
            java.lang.String signalName,
            java.util.Map<java.lang.String,java.lang.Object> parameters)
            throws java.lang.Exception

handles an external trigger.

An external trigger that comes into an execution through one of the Execution.signal() methods, will be delegated to the node in which the execution is positioned when it receives the external trigger.

The signal method implements how the node will react on that signal. For example, the outgoing transition could be taken that corresponds with the given signal.

Parameters:

execution - the Execution for which the signal is given

signalName - is an abstract text that can be associated with a signal. this corresponds to e.g. a method name in a java class interface. The implementation can decide e.g. to use the signal to identify the outgoing transition.

parameters - is extra information that can be provided with a signal. In this way, it is somewhat similar to the parameters that can be fed into a method invocation through reflection.

Throws:

java.lang.Exception - to indicate any kind of failure. Note that exceptions are considered non recoverable. After an Exception, the execution should not be used any more and if this is during a transaction, the transaction should be rolled back.