This static method listens for messages on one or more queues for one or more consumers as specified in the array of OracleAQAgent objects. The Name property of the OracleAQAgent object represents the name of the consumer and the Address property of the OracleAQAgent object represents the name of the queue.

In case of timeout, this method returns null.

Declaration

// C#
public static OracleAQAgent Listen(OracleConnection con, OracleAQAgent[]
  listenConsumers, int waitTime);

Parameters

• con

  An OracleConnection instance.

• listenConsumers

  The array of consumers being listened for. The name of the OracleAQAgent object must be null or empty for single consumer queues.

• waitTime

  Wait time in seconds.

Return Value

An OracleAQAgent object.

Exceptions

ArgumentNullException - The con or listenConsumers parameter is null.

InvalidOperationException - The connection is not open.

ArgumentException - waitTime is less than -1.

Remarks

Listen is useful in situations where one needs to monitor multiple queues until a message is available for a consumer in one of the queues. The Name property of the OracleAQAgent object represents the name of the consumer and the Address property of the OracleAQAgent object represents the name of the queue.

A waitTime of -1 implies an infinite wait time.

This call blocks the calling thread until there is a message ready for consumption for a consumer in the list. It returns an OracleAQAgent object which specifies the consumer and queue for which a message is ready to be dequeued.