Meta-object attributes configuration

The connector for MQ Integrator Broker can recognize and read two kinds of meta-objects:

The attribute values of the dynamic child meta-object duplicate and override those of the static meta-object.

Static meta-object

The MQ Integrator Broker configuration meta-object consists of a list of conversion properties defined for different business objects. To define the conversion properties for a business object, first create a string attribute and name it using the syntax busObj_verb. For example, to define the conversion properties for a Customer object with the verb Create, create an attribute named Customer_Create. In the application-specific information of the attribute, you specify the actual conversion properties.

Note:
If a static meta object is not specified, the connector is unable to map a given message format to a specific business object type during polling. When this is the case, the connector passes the message text to the configured data handler without specifying a business object. If the data handler cannot create a business object based on the text alone, the connector reports an error indicating that this message format is unrecognized.

Table 19 describes the meta-object properties.

Table 19. MQ Integrator Broker meta-object properties

Property name Description
InputFormat The InputFormat is the message format to associate with the given business object. When a message is retrieved and is in this format, it is converted to the given business object if possible. If this format is not specified for a business object, the connector does not handle subscription deliveries for the given business object. Do not set this property using default conversion properties; its value is used to match incoming messages to business objects.
InputQueue The input queue that the connector polls to detect new messages. You can use connector-specific properties to configure multiple InputQueues and optionally map different data handlers to each queue. Do not set this property using default conversion properties; its value is used to match incoming messages to business objects.
OutputFormat The OutputFormat is set on messages created from the given business object. If the OutputFormat is not specified, the input format is used, if available.
OutputQueue The OutputQueue is the output queue to which messages derived from the given business object are delivered.
ResponseTimeout Indicates the length of time in milliseconds to wait before timing out when waiting for a response. The connector returns SUCCESS immediately without waiting for a response if this is left undefined or with a value less than zero.
TimeoutFatal If this property is defined and has a value of True, the connector returns APP_RESPONSE_TIMEOUT when a response is not received within the time specified by ResponseTimeout. All other threads waiting for response messages immediately return APP_RESPONSE_TIMEOUT to InterChange Server. This causes InterChange Server to terminate the connector.

Additionally, a reserved property named Default can be defined in the meta-object. When this property is present, its application-specific information specifies default values for all business object conversion properties.


Table 20. MQ Integrator Broker static meta-object structure for Customer_Create

Property name Application-Specific Text
Default OutputFormat=CUST_OUT; OutputQueue=QueueA; ResponseTimeout=10000; TimeoutFatal=False

Application-specific information

The application-specific information is structured in name-value pair format, separated by semicolons. For example:

InputFormat=CUST_IN;OutputFormat=CUST_OUT

Mapping data handlers to InputQueues

You can use the InputQueue property in the application-specific information of the static meta-object to associate a data handler with an input queue. This feature is useful when dealing with multiple trading partners who have different formats and conversion requirements. To do so you must:

  1. Use connector-specific properties (see InputQueue) to configure one or more input queues.
  2. For each input queue, specify the queue manager and input queue name as well as data handler class name and mime type in the application-specific information.

For example, the following attribute in a static meta-object associates a data handler with an InputQueue named CompReceipts:

[Attribute]
Name = Cust_Create
Type = String
Cardinality = 1
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
AppSpecificInfo = InputQueue=//queue.manager/CompReceipts;DataHandlerClassName=
com.crossworlds.DataHandlers.MQ.disposition_notification;DataHandlerMimeType=
message/
disposition_notification
IsRequiredServerBound = false
[End]

Overloading input formats

When retrieving a message, the connector normally matches the input format to one specific business object and verb combination. The connector then passes the business object name and the contents of the message to the data handler. This allows the data handler to verify that the message contents correspond to the business object that the user expects.

If, however, the same input format is defined for more than one business object, the connector will be unable to determine which business object the data represents before passing it to the data handler. In such cases, the connector passes the message contents only to the data handler and then looks up conversion properties based on the business object that is generated. Accordingly, the data handler must determine the business object based on the message content alone.

If the verb on the generated business object is not set, the connector searches for conversion properties defined for this business object with any verb. If only one set of conversion properties is found, the connector assigns the specified verb. If more properties are found, the connector fails the message because it is unable to distinguish among the verbs.

Sample meta-object

The meta-object shown below configures the connector to convert Customer business objects using verbs Create, Update, Delete, and Retrieve.Note that the attribute Default is defined in the meta-object. Accordingly, the connector uses the conversion properties of this attribute (OutputQueue=CustomerQueue1;ResponseTimeout=5000;TimeoutFatal=true). Thus, unless specified otherwise by an attribute, the connector will issue all business objects to queue CustomerQueue1 and then wait for a response message. If a response does not arrive within 5000 milliseconds, the connector terminates immediately.

Customer object with verb create

Attribute Customer_Create indicates to the connector that any messages of format NEW should be converted to a Customer business object with the verb Create. Since an output format is not defined, the connector will send messages representing this object-verb combination using the format defined for input (in this case NEW).

Customer object with verbs update and delete

Input format MODIFY is overloaded--defined for both business object Customer with verb Update and business object Customer with verb Delete. In order to successfully process retrieved messages of this format, the business object name and possibly the verb should be contained in the message content for the data handler to identify (see Overloading input formats). For Request processing operations, the connector will send messages for either verb using the input format MODIFY since an output format is not defined.

Customer object with verb retrieve

Attribute Customer_Retrieve specifies that business objects of type Customer with verb Retrieve should be sent as messages with format Retrieve. Note that the default response time has been overridden so that the connector will wait up 10000 milliseconds before timing out (it will still terminate if a response is not received).

[ReposCopy]
Version = 3.1.0
Repositories = 1cHyILNuPTc=
[End]
[BusinessObjectDefinition]
Name = Sample_MO
Version = 1.0.0
 
[Attribute]
Name = Default
Type = String
Cardinality = 1
MaxLength = 1
IsKey = true
IsForeignKey = false
IsRequired = false
AppSpecificInfo = OutputQueue=CustomerQueue1;ResponseTimeout=5000;TimeoutFatal=true
IsRequiredServerBound = false
[End]
[Attribute]
Name = Customer_Create
Type = String
Cardinality = 1
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
AppSpecificInfo = InputFormat=NEW
IsRequiredServerBound = false
[End]
[Attribute]
Name = Customer_Update
Type = String
Cardinality = 1
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
AppSpecificInfo = InputFormat=MODIFY
IsRequiredServerBound = false
[End]
[Attribute]
Name = Customer_Delete
Type = String
Cardinality = 1
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
AppSpecificInfo = InputFormat=MODIFY
IsRequiredServerBound = false
[End]
[Attribute]
Name = Customer_Retrieve
Type = String
Cardinality = 1
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
AppSpecificInfo = OutputFormat=RETRIEVE;ResponseTimeout=10000
IsRequiredServerBound = false
[End]
[Attribute]
Name = ObjectEventId
Type = String
MaxLength = 255
IsKey = false
IsForeignKey = false
IsRequired = false
IsRequiredServerBound = false
[End]
 
[Verb]
Name = Create
[End]
 
[Verb]
Name = Delete
[End]
 
[Verb]
Name = Retrieve
[End]
 
[Verb]
Name = Update
[End]
[End]

Dynamic child meta-object

If it is difficult or unfeasible to specify the necessary meta-data through a static meta-object, the connector can optionally accept meta-data specified at run-time for each business object instance.

The connector recognizes and reads conversion properties from a dynamic meta-object that is added as a child to the top-level business object passed to the connector. The attribute values of the dynamic child meta-object duplicate the conversion properties that you can specify via the static meta-object that is used to configure the connector.

Since dynamic child meta object properties override those found in static meta-objects, if you specify a dynamic child meta-object, you need not include a connector property that specifies the static meta-object. Accordingly, you can use a dynamic child meta-object independently of the static meta-object and vice-versa.

Note:
The connector does not support use of a dynamic child meta-object to supply a collaboration name during synchronous event delivery.

Tables Table 20 and Table 21 show sample static and dynamic child meta-objects, respectively, for business object Customer_Create. Note that the application-specific information consists of semi-colon delimited name-value pairs.

Table 21. MQ Integrator Broker dynamic child meta-object structure for Customer_Create

Property name Value
OutputFormat CUST_OUT
OutputQueue QueueA
ResponseTimeout 10000
TimeoutFatal False

The connector checks the application-specific information of top-level business object received to determine whether tag cw_mo_conn specifies a child meta-object. If so, the dynamic child meta-object values override those specified in the static meta-object.

Population of the dynamic child meta-object during polling

In order to provide collaborations with more information regarding messages retrieved during polling, the connector populates specific attributes of the dynamic meta-object, if already defined for the business object created.

Table Table 22 shows how a dynamic child meta-object might be structured for polling.

Table 22. MQ Integrator Broker dynamic child meta-object structure for polling

Property name Sample value
InputFormat CUST_IN
InputQueue MYInputQueue
OutputFormat CxIgnore
OutputQueue CxIgnore
ResponseTimeout CxIgnore
TimeoutFatal CxIgnore

As shown in Table 22, you can define additional attributes, Input_Format and InputQueue, in a dynamic child meta-object. The Input_Format is populated with the format of the message retrieved, while the InputQueue attribute contains the name of the queue from which a given message has been retrieved. If these properties are not defined in the child meta-object, they will not be populated.

Example scenario:

Sample dynamic child meta-object

[BusinessObjectDefinition]
Name = MO_Sample_Config
Version = 1.0.0
 
[Attribute]
Name = OutputFormat
Type = String
MaxLength = 1
IsKey = true
IsForeignKey = false
IsRequired = false
DefaultValue = CUST
IsRequiredServerBound = false
[End]
[Attribute]
Name = OutputQueue
Type = String
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
DefaultValue = OUT
IsRequiredServerBound = false
[End]
[Attribute]
Name = ResponseTimeout
Type = String
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
DefaultValue = -1
IsRequiredServerBound = false
[End]
[Attribute]
Name = TimeoutFatal
Type = String
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
DefaultValue = false
IsRequiredServerBound = false
[End]
[Attribute]
Name = InputFormat
Type = String
MaxLength = 1
IsKey = true
IsForeignKey = false
IsRequired = false
IsRequiredServerBound = false
[End]
[Attribute]
Name = InputQueue
Type = String
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
IsRequiredServerBound = false
[End]
[Attribute]
Name = ObjectEventId
Type = String
MaxLength = 255
IsKey = false
IsForeignKey = false
IsRequired = false
IsRequiredServerBound = false
[End]
 
[Verb]
Name = Create
[End]
 
[Verb]
Name = Delete
[End]
 
[Verb]
Name = Retrieve
[End]
 
[Verb]
Name = Update
[End]
[End]
[BusinessObjectDefinition]
Name = Customer
Version = 1.0.0
AppSpecificInfo = cw_mo_conn=MyConfig
 
[Attribute]
Name = FirstName
Type = String
MaxLength = 1
IsKey = true
IsForeignKey = false
IsRequired = false
IsRequiredServerBound = false
[End]
[Attribute]
Name = LastName
Type = String
MaxLength = 1
IsKey = true
IsForeignKey = false
IsRequired = false
IsRequiredServerBound = false
[End]
[Attribute]
Name = Telephone
Type = String
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
IsRequiredServerBound = false
[End]
[Attribute]
Name = MyConfig
Type = MO_Sample_Config
ContainedObjectVersion = 1.0.0
Relationship = Containment
Cardinality = 1
MaxLength = 1
IsKey = false
IsForeignKey = false
IsRequired = false
IsRequiredServerBound = false
[End]
[Attribute]
Name = ObjectEventId
Type = String
MaxLength = 255
IsKey = false
IsForeignKey = false
IsRequired = false
IsRequiredServerBound = false
[End]
 
[Verb]
Name = Create
[End]
 
[Verb]
Name = Delete
[End]
 
[Verb]
Name = Retrieve
[End]
 
[Verb]
Name = Update
[End]
[End]

JMS headers, MQ Integrator Broker message properties, and dynamic child meta-object attributes

You can add attributes to a dynamic meta-object to gain more information about, and more control over, the message transport. Adding such attributes allows you to modify JMS properties, to control the ReplyToQueue on a per-request basis (rather than using the default ReplyToQueue specified in the adapter properties), and to re-target a message CorrelationID. This section describes these attributes and how they affect event notification and request processing in both synchronous and asynchronous modes.

The following attributes, which reflect JMS and MQ Integrator Broker header properties, are recognized in the dynamic meta-object.

Table 23. Dynamic meta-object header attributes

Header attribute name Mode Corresponding JMS header
CorrelationID
Read/Write JMSCorrelationID
ReplyToQueue
Read/Write JMSReplyTo
DeliveryMode
Read/Write JMSDeliveryMode
Priority
Read/Write JMSPriority
Destination
Read JMSDestination
Expiration
Read JMSExpiration
MessageID
Read JMSMessageID
Redelivered
Read JMSRedelivered
TimeStamp
Read JMSTimeStamp
Type
Read JMSType
UserID
Read JMSXUserID
AppID
Read JMSXAppID
DeliveryCount
Read JMSXDeliveryCount
GroupID
Read JMSXGroupID
GroupSeq
Read JMSXGroupSeq
JMSProperties
Read/Write

Read-only attributes are read from a message header during event notification and written to the dynamic meta-object. These properties also populate the dynamic meta-object when a response message is issued during request processing. Read/write attributes are set on message headers created during request processing. During event notification, read/write attributes are read from message headers to populate the dynamic meta-object.

The interpretation and use of these attributes are described in the sections below.

Note:
None of the above attributes are required. You may add any attributes to the dynamic meta-object that relate to your business process.

Synchronous event notification

For synchronous event processing, the adapter posts an event and waits for a response from the integration broker before sending a response message back to the application. Any changes to the business data are reflected in the response message returned. Before posting the event, the adapter populates the dynamic meta-object just as described for asynchronous event notification. The values set in the dynamic meta-object are reflected in the response-issued header as described below (all other read-only header attributes in the dynamic meta-object are ignored.):

Asynchronous request processing

The connector uses the dynamic meta-object, if present, to populate the request message prior to issuing it. The connector performs the following steps before sending a request message:

  1. If attribute CorrelationID is present in the dynamic meta-object, the connector sets the CorrelationID of the outbound request message to this value.
  2. If attribute ReplyToQueue is specified in the dynamic meta-object, the connector passes this queue via the request message and waits on this queue for a response. This allows you to override the ReplyToQueuevalue specified in the connector configuration properties. If you additionally specify a negative ResponseTimeout (meaning that the connector should not wait for a response), theReplyToQueue is set in the response message, even though the connector does not actually wait for a response.
  3. If attribute JMSProperties is specified in the dynamic meta-object, the corresponding JMS properties specified in the child dynamic meta-object are set in the outbound message sent by the connector.

Note:
If header attributes in the dynamic meta-object are undefined or specify CxIgnore, the connector follows its default settings.

Synchronous request processing

The connector uses the dynamic meta-object, if present, to populate the request message prior to issuing it. If the dynamic meta-object contains header attributes, the connector populates it with corresponding new values found in the response message. The connector performs the following steps (in addition to populating the meta-object with transport-related data) after receiving a response message:

  1. If attribute CorrelationID is present in the dynamic meta-object, the adapter updates this attribute with the JMSCorrelationID specified in the response message.
  2. If attribute ReplyToQueue is defined in the dynamic meta-object, the adapter updates this attribute with the name of the JMSReplyTo specified in the response message.
  3. If attribute DeliveryMode is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSDeliveryMode header field of the message. If attribute DeliveryMode is set to 2, the message is sent persistently. If DeliveryMode is set to 1, the message is not sent persistently. Any other value will fail the connector. If DeliveryMode is not specified in the MO, then the JMS provider establishes the persistence setting.
  4. If attribute Priority is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSPriority header field of the message.
  5. If attribute Destination is defined in the dynamic meta-object, the adapter updates this attribute with the name of the JMSDestination specified in the response message.
  6. If attribute Expiration is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSExpiration header field of the message.
  7. If attribute MessageID is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSMessageID header field of the message.
  8. If attribute Redelivered is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSRedelivered header field of the message.
  9. If attribute TimeStamp is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSTimeStamp header field of the message.
  10. If attribute Type is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSType header field of the message.
  11. If attribute UserID is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSXUserID header field of the message.
  12. If attribute AppID is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSXAppID property field of the message.
  13. If attribute DeliveryCount is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSXDeliveryCount header field of the message.
  14. If attribute GroupID is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSXGroupID header field of the message.
  15. If attribute GroupSeq is present in the dynamic meta-object, the adapter updates this attribute with the value of the JMSXGroupSeq header field of the message.
  16. If attribute JMSProperties is defined in the dynamic meta-object, the adapter updates any properties defined in the child object with the values found in the response message. If a property defined in the child object does not exist in the message, the value is set to CxBlank.

Note:
Using the dynamic meta-object to change the CorrelationID set in the request message does not affect the way the adapter identifies the response message--the adapter by default expects that the CorrelationID of any response message equals the message ID of the request sent by the adapter.

Error Handling

If a JMS property cannot be read from or written to a message, the connector logs an error and the request or event fails. If a user-specified ReplyToQueue does not exist or cannot be accessed, the connector logs an error and the request fails. If a CorrelationID is invalid or cannot be set, the connector logs an error and the request fails. In all cases, the message logged is from the connector message file.

Copyright IBM Corp. 1997, 2003