Package com.qfs.msg

Interface IMessageChannel<I,E>

Type Parameters:

I - type of the identifiers of messages.

E - type of the data elements appended into message chunks.

All Known Subinterfaces:

IStoreCompositeMessageChannel<I,E>, IStoreMessageChannel<I,E>

All Known Implementing Classes:

AMessageChannel, AStoreMessageChannel, CompositeMessageChannel, CompositeStoreMessageChannel, StoreMessageChannel

public interface IMessageChannel<I,E>

The message channel interface.

This channel listens or fetches the data from a data source. It uses the specific information (message identifier) for this channel to notify which element has started or completed.

Author:

ActiveViam

Method Summary

Modifier and Type	Method	Description
String	getTopic()	Retrieves the topic of this channel.
<T extends I> IMessage<T,E>	newMessage(T identifier)	Creates a new message that will collect data elements from the source, and then be sent through the channel.
<T extends I> void	send(IMessage<T,E> message)	Sends a message through the channel.
<T extends I> void	sendMessage(T identifier, Collection<? extends E> elements)	Creates a new message and sends it through the channel.
IMessageChannel<I,E>	withMessageHandler(IMessageHandler<I> messageHandler)	Installs a message handler on this channel.

Method Detail

getTopic

String getTopic()

Retrieves the topic of this channel.

Returns:

The channel's topic

newMessage

<T extends I> IMessage<T,E> newMessage(T identifier)

Creates a new message that will collect data elements from the source, and then be sent through the channel.

Type Parameters:

T - Type of the message identifier.

Parameters:

identifier - the identifier of the message

Returns:

the created message

send

<T extends I> void send(IMessage<T,E> message)

Sends a message through the channel. The channel always supports sending the message instances it has created, but only optionally supports sending other message types.
Note : In some message implementations, the publishing of partial messages is already done during the IMessage.append(IMessageChunk) method (for example, on store messages in non-accumulating mode). In that case, calling this method will have no further effect.

Type Parameters:

T - Type of the message identifier.

Parameters:

message - The message to send through the channel.

sendMessage

<T extends I> void sendMessage(T identifier,
                               Collection<? extends E> elements)

Creates a new message and sends it through the channel. This is a utility method that combines creating the message, creating a message chunk to hold the elements and appending it to the message, and then sending the message.

Type Parameters:

T - Type of the message identifier.

Parameters:

identifier - The identifier of the new message to create.

elements - The elements to add in the message to send through the channel.

See Also:

newMessage(Object), IMessage.newChunk(), IMessage.append(IMessageChunk), send(IMessage)

withMessageHandler

IMessageChannel<I,E> withMessageHandler(IMessageHandler<I> messageHandler)

Installs a message handler on this channel.

Parameters:

messageHandler - the new message handler

Returns:

this channel after its message handler has been updated