Module org.mule.sdk.api
Package org.mule.sdk.api.runtime.source

Class Source<T,A>

java.lang.Object
org.mule.sdk.api.runtime.source.Source<T,A>
Type Parameters:
T - the generic type for the generated message's payload
A - the generic type for the generated message's attributes
Direct Known Subclasses:
PollingSource
@MinMuleVersion("4.4") public abstract class Source<T,A> extends Object
Base class to write message sources compliant with a given SourceModel.

This class acts as an adapter between the extensions API representation of a message source and Mule's actual MessageSource concept.

This class relies on generics to specify the payload and attribute types that the source is going to generate. Although the java compiler does allow for raw uses of the class, this API forbids that since those generics are needed for metadata purposes. For the case of Sources which don't generate a response, the Payload is to be assigned to Void.

If the source emits responses back to a client, then it must be annotated with EmitsResponse. Notice that although such annotation is required, the mere fact of using that annotation doesn't make the source automatically send the response, that logic must be coded on each source.

Implementations can contain methods annotated with OnSuccess and/or OnError to listen for the results of processing the generated messages. As specified, on the javadoc of those annotations, the annotated methods support parameter resolution just like the operations do. If the source is also annotated with EmitsResponse, these methods will be very useful to actually sending those responses. Notice however, that you can still have these methods and perform actions other than emitting responses if needed.

Since:
1.0

  • Constructor Summary

    Constructors
    Constructor
    Description
    Source()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    abstract void
    onStart(SourceCallback<T,A> sourceCallback)
    This method will be invoked by the runtime to make the source start producing messages.
    abstract void
    onStop()
    This method will be invoked by the runtime to make the source stop producing messages.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Source

      public Source()

  • Method Details

    • onStart

      public abstract void onStart(SourceCallback<T,A> sourceCallback) throws org.mule.runtime.api.exception.MuleException
      This method will be invoked by the runtime to make the source start producing messages.

      Each generated message will be passed back to the runtime through the given sourceCallback for processing.

      This method should throw an exception if the source fails to start, but any other exception encountered during the process of generating messages, should be communicated to the runtime through the SourceCallback.onConnectionException(ConnectionException)} method.

      Only the runtime should invoke this method. Do not do it manually

      Parameters:
      sourceCallback - a SourceCallback
      Throws:
      org.mule.runtime.api.exception.MuleException - If the source fails to start.

    • onStop

      public abstract void onStop()
      This method will be invoked by the runtime to make the source stop producing messages.

      This method should not fail. Any exceptions found during the stop process should be logged and correctly handled by the source, but after invoking this method the source must:

      • Stop producing messages
      • Free any allocated resources
      • Be capable of being restarted

      Only the runtime should invoke this method. Do not do it manually