JMS message selector

A message selector allows a JMS consumer to be more selective about the messages that it receives from a particular topic or queue.

A message selector uses message properties and headers as criteria in conditional expressions. These expressions use Boolean logic to declare which messages are delivered to a client, such as the JMSInput node.

The following table demonstrates the construction of a message selector. It comprises an identifier, such as the JMSPriority header, or an application controlled property myProperty1. The selector string must specify an operator followed by a literal.

Element	Valid values
Identifiers	Property or header field reference (such as `JMSPriority`, `myProperty1`) The following values are not possible: NULL, TRUE, FALSE, NOT, AND, OR, BETWEEN, LIKE, IN, IS
Operators	AND, OR, LIKE, BETWEEN, =, <>, <,>, <=, >=, IS NULL, IS NOT NULL
Literals	The two Boolean literals, TRUE and FALSE Exact number literals that have no decimal point; for example, +25, -399, 40 Approximate number literals. These literals can use scientific notation or decimal; for example, -21.4E4, 5E2, +34.4928 String literals, for example `TargetFunctionName='createOrderOnSuccess'`

The JMSInput and JMSReceive nodes provide a free format string PropertySelector, to specify selectors that filter or include application properties. These nodes also have properties for specific header properties, where the identifier is implicit and is generated by the node. For the header selectors, the operator and literal part of the string must be specified.

If more than one selector is specified the node generates a composite selector string, where the individual selector strings are concatenated with the AND operator, and each selector string part is wrapped with parentheses.

The following are examples for each of the selector properties:

Selector property	Description
PropertySelector	`OrderValue> 100.00` This string is used directly as shown. In the JMSInput node, this property is configured by the Application property field.
TimeStamp	`BETWEEN 1057576423231 AND 10575788993265` Messages that are put between these two Java™ times only (where Java time is milliseconds since 01 Jan 1970 ) is delivered to the JMSInput node. In this case, the string generated is prefixed with the identifier `JMSTimestamp`.
Delivery Mode	`PERSISTENT` This setting means that only messages marked by the sender as being `PERSISTENT` should be delivered to the JMSInput node. In this case, the string that is generated is prefixed with the identifier `JMSDeliveryMode`.
Priority	`>= 5 AND <= 8` This setting means that only messages marked by the sender as having a priority `5`, `6`, `7`, or `8` are delivered to the JMSInput node. In this case, the string generated is prefixed with the identifier `JMSPriority`.
Message ID	`> WMBRK123456` This setting returns messages with a Message ID that is greater than the value specified. In this case, the string generated is prefixed with the identifier `JMSMessageID`.
Redelivered	`FALSE` This setting means that messages that have not been redelivered are received by the node. In this case, the string generated is prefixed with the identifier `JMSRedelivered`.
Correlation ID	`= WMBRKABCDEFG` This setting returns messages whose Correlation ID is equal to the value `WMBRKBABCDEFG`. In this case, the string generated is prefixed with the identifier `JMSCorrelationID`.