com.caplin.datasource.messaging

Interface Message

All Known Subinterfaces:

ContainerMessage, GenericMessage, MappingMessage, NewsMessage, PageMessage, PermissionMessage, RecordMessage, RecordType1Message, RecordType2Message, RecordType3Message, StoryMessage, WrapperMessage

public interface Message

A Message represents a DataSource message containing an update to an existing subject or a complete image of it.

Message is the base interface for all messages generated by DataSource regardless of the message type. Therefore the base interface provides no functionality for altering the content of the message and one of the following derived interfaces should be used to add data to a Message:

• RecordType1Message
• RecordType2Message
• RecordType3Message
• GenericMessage
• ContainerMessage
• PermissionMessage
• NewsMessage
• StoryMessage
• PageMessage

You do not have to implement this interface yourself. Implementations of Message can be created by calling the relevant creation method on MessageFactory; for example, MessageFactory.createRecordType1Message(String) or MessageFactory.createContainerMessage(String).

The following example sends a Type 1 record image to all subscribed peers.

import com.caplin.datasource.messaging.record.RecordType1Message;
import com.caplin.datasource.publisher.Publisher;

public class SendingARecordImage
{
        void sendRecordImage(Publisher publisher, String subject)
        {
                RecordType1Message message = publisher.getMessageFactory().createRecordType1Message(subject);
                
                // Indicate that this is an image.
                message.setImage(true);
                
                // Add a Bid and Ask field to the message.
                message.setField("Bid", "22.0");
                message.setField("Ask", "22.1");
                
                // Send the message to the subscribed peers.
                publisher.publishToSubscribedPeers(message);
        }
}

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.String	getSubject() Gets the subject of this message.
boolean	isImage() Gets a boolean value indicating whether this Message represents an image or an update.
void	setImage(boolean image) Sets a boolean value indicating whether this Message represents an image of the data or an update to it.

Method Detail

isImage

boolean isImage()

Gets a boolean value indicating whether this Message represents an image or an update. By default, this method returns false indicating that the Message is an update and not an image. To change a message to be an image, call setImage(boolean) passing in the value true.

Returns:

true if this message is an image of the object, false if it is an update to the existing state of the object.

setImage

void setImage(boolean image)

Sets a boolean value indicating whether this Message represents an image of the data or an update to it. By default, a newly created Message is deemed to be an update and not an image.

Parameters:

image - When set to true, the receiver will clear all previous data for that subject before adding the sent data. When set to false, the receiver adds the sent data to previous data sent to that subject.

getSubject

java.lang.String getSubject()

Gets the subject of this message.

Returns:

The subject.