JMS protocol

Decision Server Insights can receive and send events in the form of JMS text messages or JMS bytes messages. The messaging provider can be either WebSphere® MQ or WebSphere Application Server.

JMS inbound message format and encoding

Table 1. HTTP inbound message format and encoding
Message format (from binding)	Message type	Message content	Character encoding
`application/xml` or `text/xml`	`TextMessage`	Message text parsed as XML.	As presented by the messaging provider. The encoding that is specified in the XML directive is ignored.
`application/xml` or `text/xml`	`BytesMessage`	Message bytes parsed as XML.	If present, the JMS_IBM_Character_Set message property is authoritative. Otherwise, the encoding that is specified in the XML directive is used.
`application/json`	`TextMessage`	Message text parsed as JSON.	As presented by the messaging provider.
`application/json`	`BytesMessage`	Message bytes parsed as JSON.	If present, the JMS_IBM_Character_Set message property is authoritative. Otherwise, UTF-8 is used.

An inbound JMS endpoint expects a message that conforms to the message format that is specified by the associated inbound binding definition. If the inbound binding specifies application/xml or text/xml, the message must either conform to an XML schema that represents an event type (TYPED_XML), or must be classified and transformed by the inbound binding definition. If the inbound binding specifies application/json, the message must contain a JSON representation of an event. An inbound JMS endpoint rejects messages that contain invalid XML or JSON content. However, an inbound JMS endpoint accepts and discards messages that contain valid XML or JSON documents but nevertheless cannot be identified as instances of event types defined by the business model of the solution.

For more information about the JMS_IBM_Character_Set message property, see JMS client message conversion and encoding.

Note: When an XML or JSON message is delivered to an inbound JMS endpoint, the system allocates a unique internal identifier for the event that is submitted to the solution. Subsequently, if an identical message is delivered, an event with a new unique internal identifier is submitted.

JMS outbound message format and encoding

Table 2. JMS outbound message format and encoding
Message format (from binding)	Message type	Message content	Character encoding
`application/xml` or `text/xml`	`TextMessage`	Message text contains XML 1.1 content. The encoding UTF-8 is specified in XML directive.	The message includes a JMS_IBM_Character_Set message property with the value UTF-8.
`application/xml` or `text/xml`	`BytesMessage`	Message bytes contain XML 1.1 content. The encoding UTF-8 is specified in XML directive.	The message includes a JMS_IBM_Character_Set message property with the value UTF-8.
`application/json`	`TextMessage`	Message text contains JSON content.	The message includes a JMS_IBM_Character_Set property with the value UTF-8.
`application/json`	`BytesMessage`	Message bytes contain JSON content using UTF-8 encoding.	The message includes a JMS_IBM_Character_Set message property with the value UTF-8.

By default, the outbound JMS message is a TextMessage with the JMS delivery mode PERSISTENT. These settings can be customized for individual outbound JMS endpoints by using advanced properties.

If the outbound binding specifies application/xml or text/xml, the message conforms to the XML schema that represents the event (TYPED_XML), or is transformed according to the outbound binding definition. If the outbound binding specifies application/json, the message contains the JSON representation of the event. The outbound binding can also specify JMS type, JMS correlation ID, and message property values.