Network Deployment (Distributed operating systems), v8.0 > Reference > Developer detailed usage information

SIMessage

The SIMessage interface is the public interface to a service integration bus message for use by mediations and other service integration bus components. This interface extends java.lang.Cloneable and java.lang.Serializable.

The version of Service Data Objects (SDO) supported by mediations is v1.

The SIMessage interface has many methods allowing you to work with message properties, header contents, routing path, metadata, and others:

• The method getDataGraph returns the SDO data graph. This contains the SIMessage payload content in a tree representation. Using the data graph, you can work directly with individual fields in the message payload. For more information about SDO data graphs, see SDO data graphs.
• We can transcode a message payload by calling the method getNewDataGraph(format). It returns a copy of the payload in the new format. We can write the new datagraph back to the message by using setDataGraph(DataGraph, format). See Transcoding between message formats.

• To log a message as a simple byte stream, you can retrieve the message payload as a byte array by using the method getDataGraphAsBytes. For more information about converting from data graph to bytes, and back again, see Transcoding a message payload into a byte array and Transcoding a byte array into a message payload.
• There are methods to get, set, delete and clear user properties and message properties. We can also retrieve a list of user property names. For more information about working with properties, see Work with message properties.

• Forward and reverse routing paths define a sequential list of intermediate bus destinations through which messages pass to reach a target bus destination. You use a routing path to apply the mediations configured on several destinations to the messages sent along the path. The following methods allow you to get and set the contents of the ForwardRoutingPath and ReverseRoutingPath for an SIMessage:
  • getForwardRoutingPath()
  • setForwardRoutingPath()
  • getReverseRoutingPath()
  • setReverseRoutingPath()

  For more information about routing paths, see Destination routing paths. For information about how to work with routing addresses, see Set routing addresses in a message header.

• If your mediation changes the content of the message, there is a risk that the message is no longer valid. If the data graph is not valid, the message cannot be sent through the service integration bus or stored in the message store. In this case, the message is not well formed. A message is well formed when all the values of the message properties might be serialized, and the data graph of the message conforms to the format of the message. We can test your message by using the method isWellFormed. It returns true when the message contains a well formed data graph. This test has implications for performance. See Set tuning properties for a mediation.
• We can work with the time for the message to live, measured in milliseconds from the time when the message was originally sent:
  • The methods getTimeToLive and setTimeToLive allow you to get and set the value of the TimeToLive field in the message header. A value of 0 indicates that the message will never expire.
  • The methods getRemainingTimeToLive and setRemainingTimeToLive allow you to get the remaining time in milliseconds before the message expires, and set the remaining time in milliseconds before the message should expire.

For more information about SIMessage, see the API documentation.
Mediation programming
API documentation - Application programming interfaces (package: com.ibm.websphere.sib, class: SIMessage

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