org.hawkular.bus.common

Class BasicMessage

java.lang.Object

org.hawkular.bus.common.BasicMessage

Direct Known Subclasses:

ObjectMessage, SimpleBasicMessage

public abstract class BasicMessage
extends Object

Basic information that is sent over the message bus. The message ID is assigned by the messaging framework and so typically is not explicitly set. The correlation ID is a message ID of another message that was sent previously. This is usually left unset unless this message needs to be correlated with another. As an example, when a process is stopped, you can correlate the "Stopped" event with the "Stopping" event so you can later determine how long it took for the process to stop. The headers are normally those out-of-band properties that are sent with the message.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BasicMessage()

Method Summary

Modifier and Type	Method and Description
static <T extends BasicMessage> T	fromJSON(String json, Class<T> clazz) Convenience static method that converts a JSON string to a particular message object.
MessageId	getCorrelationId() If this message is correlated with another message, this will be that other message's ID.
Map<String,String>	getHeaders() The headers that were shipped along side of the message when the message was received.
MessageId	getMessageId() Returns the message ID that was assigned to this message by the messaging infrastructure.
void	setCorrelationId(MessageId correlationId)
void	setHeaders(Map<String,String> headers) Sets headers that will be sent with the message when the message gets delivered.
void	setMessageId(MessageId messageId)
String	toJSON() Converts this message to its JSON string representation.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicMessage

protected BasicMessage()

Method Detail

fromJSON

public static <T extends BasicMessage> T fromJSON(String json,
                                                  Class<T> clazz)

Convenience static method that converts a JSON string to a particular message object.

Parameters:

json - the JSON string

clazz - the class whose instance is represented by the JSON string

Returns:

the message object that was represented by the JSON string

toJSON

public String toJSON()

Converts this message to its JSON string representation.

Returns:

JSON encoded data that represents this message.

getMessageId

public MessageId getMessageId()

Returns the message ID that was assigned to this message by the messaging infrastructure. This could be null if the message has not been sent yet.

Returns:

message ID assigned to this message by the messaging framework

setMessageId

public void setMessageId(MessageId messageId)

getCorrelationId

public MessageId getCorrelationId()

If this message is correlated with another message, this will be that other message's ID. This could be null if the message is not correlated with another message.

Returns:

the message ID of the correlated message

setCorrelationId

public void setCorrelationId(MessageId correlationId)

getHeaders

public Map<String,String> getHeaders()

The headers that were shipped along side of the message when the message was received. The returned map is an unmodifiable read-only view of the properties. Will never return null but may return an empty map.

Returns:

a read-only view of the name/value properties that came with the message as separate headers.

setHeaders

public void setHeaders(Map<String,String> headers)

Sets headers that will be sent with the message when the message gets delivered. This completely replaces any existing headers already associated with this message. Note that the given name/value pairs will be copied to an internal map. If the given map is null or empty, this message's internal map will be destroyed and getHeaders() will return an empty map. Note that the header values are all expected to be strings.

Parameters:

headers - name/value properties

toString

public String toString()

Overrides:

toString in class Object