Instantiating a Destination

As with connection factories, you may sometimes find it more convenient to dispense with JNDI lookup and simply create your own queue or topic destination objects by direct instantiation. Although a variable of type Destination can accept objects of either class, you cannot directly instantiate a Destination object; the object must always belong to one of the specific classes Queue or Topic. The constructors for both of these classes accept a string argument specifying the name of the physical destination to which the object corresponds:

Destination  myDest = new com.sun.messaging.Queue("myDest");

Note, however, that this only creates a Java object representing the destination; it does not actually create a physical destination on the message broker. The physical destination itself must still be created by a Message Queue administrator, with the same name you pass to the constructor when instantiating the object.

Destination names beginning with the letters mq are reserved and should not be used by client programs.

Also, for topic destinations, a symbolic lookup name that includes wildcard characters can be used as the lookup string. See Supported Topic Destination Names in Sun Java System Message Queue 4.3 Administration Guide.

Unlike connection factories, destinations have a much more limited set of configuration properties. In fact, only two such properties are defined in the Message Queue class DestinationConfiguration: the name of the physical destination itself (imqDestinationName) and an optional descriptive string (imqDestinationDescription). Since the latter property is rarely used and the physical destination name can be supplied directly as an argument to the Queue or Topic constructor as shown above, there normally is no need (as there often is with a connection factory) to specify additional properties with the object’s setProperty method. Hence the variable to which you assign the destination object (myDest in the example above) need not be typed with the Message Queue class com.sun.messaging.Destination; the standard JMS interface javax.jms.Destination (which the Message Queue class implements) is sufficient. If you have imported the full JMS package javax.jms.*, you can simply declare the variable with the unqualified name Destination, as above, rather than with something like

com.sun.messaging.Destination
    myDest = new com.sun.messaging.Queue("myDest");

as shown earlier for connection factories.