This section explains how a feature gets a reference to the TCAP Leg Manager and how IPSMGW MAP features are triggered.
Obtaining a Reference to the TCAP Leg Manager
Features access the TCAP Leg Manager as a provider object. The first step is to add the TCAP Leg Manager provider jndi name to the raProviderJndiNames attribute of the SentinelFeature annotation. For example, the MAP Proxy features does:
/**
* Sentinel feature that acts as a proxy between two MAP Dialogs.
*/
@SentinelFeature(
featureName = IPSMGWMapProxyFeature.NAME,
// ...
raProviderJndiNames = { "sentinel/tcaplegmanagerprovider" }, 
// ...
) |
The TCAP Leg Manager is injected as a provider object using the name "sentinel/tcaplegmanagerprovider" |
The second step is to implement the InjectResourceAdaptorProvider interface in your feature. The IPSMGW will call injectResourceAdaptorProvider() when the feature is created. For example, the MAP Proxy feature does:
@BinderTargets(services = "ipsmgw")
public class IPSMGWMapProxyFeature extends BaseFeature<SentinelSessionState, FeatureEndpoint>
implements InjectResourceAdaptorProvider,
// ...
{
// ...
@Override
public void injectResourceAdaptorProvider(Object provider) {
this.tcapLegManager = (TcapLegManager)provider; 
}
// ...
private TcapLegManager tcapLegManager; 
// ...
} |
The feature must implement the InjectResourceAdaptorProvider interface … |
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… by implementing the injectResourceAdaptorProvider(Object) operation |
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It is safe for a feature to hold a reference to the TcapLegManager in a java attribute |
Triggering IPSMGW MAP Features
IPSMGW MAP Features are triggered with a trigger event object that corresponds to a class in the TCAP Messages hierachy. The triggering ActivityContextInterface is for the Dialog activity that corresponds to the triggering event object. For example the MAP Proxy does:
@Override
public void startFeature(Object trigger, Object activity,
ActivityContextInterface aci,
Map<String, ParameterValue> featureParameters)
{
final Tracer tracer = getTracer();
if (! (trigger instanceof DialogTcapMessage)) {
getCaller().featureFailedToExecute(
new FeatureError(FeatureError.Cause.unclassified,
"Feature not triggered on a DialogTcapMessage. Trigger = " + trigger));
getCaller().featureHasFinished();
return;
}
final SentinelActivityContextInterface triggerAci
= tcapLegManager.asSentinelActivityContextInterface(aci);
final TcapLeg triggerLeg = tcapLegManager.getLeg(triggerAci);
final DialogTcapMessage message = (DialogTcapMessage) trigger;
final TcapLeg proxyLeg;
switch (message.getType()) { 
case DialogOpenRequest: 
final DialogOpenRequestTcapMessage dialogOpen = message.asDialogOpenRequest();
// ...
// create the new outgoing leg
try {
proxyLeg = tcapLegManager.createLeg(dialogOpen.getApplicationContext(),
proxyLegName); 
}
catch (DuplicateLegException dle) {
// ...
return;
}
catch(ProtocolException pe) {
// ...
return;
}
// ...
break;
case DialogOpenAccept: 
proxyLeg = triggerLeg.getLinkedLeg(); 
// ...
break; |
MAP features expect trigger objects that implement DialogTcapMessage |
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A useful utility method on the TCAP Leg Manager to get a SentinelActivityContext for the trigering ACI |
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Use the TCAP Leg Manager to get the TCAP Leg for the triggering ACI |
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The MAP proxy takes actions that depend on the type of the trigger |
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On a DialogOpenRequest the MAP Proxy feature creates a new outgoing leg to proxy to |
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Use the TCAP Leg Manager to create the new proxy leg |
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The MAP proxy will process an OpenAccept to the proxy leg |
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Get the proxy leg by following the link from the triggering leg |
