Listen(OracleQueueAgentCollection,Int32,OracleQueueDeliveryMode,OracleQueueDeliveryMode,OracleConnection) Method

In This Topic

Listens on one or more queues on behalf of a list of agents.

Syntax

Visual Basic
C#

'Declaration
 
Public Overloads Shared Function Listen( _
   ByVal agents As OracleQueueAgentCollection, _
   ByVal waitTimeout As Integer, _
   ByVal listenDeliveryMode As OracleQueueDeliveryMode, _
   ByRef messageDeliveryMode As OracleQueueDeliveryMode, _
   ByVal connection As OracleConnection _
) As OracleQueueAgent

public static OracleQueueAgent Listen( 
   OracleQueueAgentCollection agents,
   int waitTimeout,
   OracleQueueDeliveryMode listenDeliveryMode,
   out OracleQueueDeliveryMode messageDeliveryMode,
   OracleConnection connection
)

Parameters

agents: List of agents to listen for.
waitTimeout: Time out for the listen call in seconds. By default, the call will block forever.
listenDeliveryMode: The caller specifies whether it is interested in persistent, buffered messages or both types of messages, specifying a delivery mode. (Only for Oracle 10.2 and greater.)
messageDeliveryMode: Returns the message type along with the queue and consumer for which there is a message (only for Oracle 10.2 and greater).
connection: A OracleConnection that represents the connection to an instance of Oracle server.

Return Value

Agent with a message available for consumption.

Example

The following example demonstrates the usage of Listen(OracleQueueAgentCollection,Int32,OracleQueueDeliveryMode,OracleQueueDeliveryMode,OracleConnection) method.

csharp

OracleConnection oracleConnection = new OracleConnection(
        "User Id=system;Password=manager;Server=ora11;");
oracleConnection.Open();

OracleQueueTable oracleQueueTable = new OracleQueueTable(
        "QUEUE_TABLE_MESSAGE", oracleConnection);

// Set the table to serve multiple consumers.
oracleQueueTable.Options.MultipleConsumers = true;
oracleQueueTable.Options.PayloadTypeName = "RAW";
oracleQueueTable.CreateQueueTable();
OracleQueueAdmin oracleQueueAdmin = new OracleQueueAdmin(
        "MESSAGE_QUEUE", "QUEUE_TABLE_MESSAGE", oracleConnection);
oracleQueueAdmin.CreateQueue();
oracleQueueAdmin.StartQueue();

oracleQueueAdmin.AddSubscriber(new OracleQueueAgent("Bob"));

OracleQueue oracleEnqueueQueue = new OracleQueue("MESSAGE_QUEUE", oracleConnection);

OracleQueueMessage message = new OracleQueueMessage();
message.StringPayload = "Message for Bob.";
message.MessageProperties.RecipientList.Add(new OracleQueueAgent("Bob"));
oracleEnqueueQueue.Enqueue(message);

OracleQueue oracleDequeueQueue = new OracleQueue();
oracleDequeueQueue.Connection = oracleConnection;

OracleQueueAgentCollection coll = new OracleQueueAgentCollection();
coll.Add(new OracleQueueAgent("Bob", "MESSAGE_QUEUE"));

// listening only for 60 seconds instead of blocking thread forever
OracleQueueAgent agent = oracleDequeueQueue.Listen(coll, 60);
            
Console.WriteLine("The following consumer received a message: {0}", agent.Name);
oracleDequeueQueue.QueueName = agent.Address;
oracleDequeueQueue.DequeueOptions.ConsumerName = agent.Name;
Console.WriteLine("The message: {0}", oracleDequeueQueue.Dequeue().StringPayload);

oracleQueueAdmin.StopQueue();
oracleQueueAdmin.DropQueue();
oracleQueueTable.DropQueueTable();

oracleConnection.Close();

Visual Basic

Dim oracleConnection As New OracleConnection("User Id=system;Password=manager;Server=ora11;")
oracleConnection.Open()

Dim oracleQueueTable As New OracleQueueTable("QUEUE_TABLE_MESSAGE", oracleConnection)

' Set the table to serve multiple consumers.
oracleQueueTable.Options.MultipleConsumers = True
oracleQueueTable.Options.PayloadTypeName = "RAW"
oracleQueueTable.CreateQueueTable()
Dim oracleQueueAdmin As New OracleQueueAdmin("MESSAGE_QUEUE", "QUEUE_TABLE_MESSAGE", oracleConnection)
oracleQueueAdmin.CreateQueue()
oracleQueueAdmin.StartQueue()

oracleQueueAdmin.AddSubscriber(New OracleQueueAgent("Bob"))

Dim oracleEnqueueQueue As New OracleQueue("MESSAGE_QUEUE", oracleConnection)

Dim message As New OracleQueueMessage()
message.StringPayload = "Message for Bob."
message.MessageProperties.RecipientList.Add(New OracleQueueAgent("Bob"))
oracleEnqueueQueue.Enqueue(message)

Dim oracleDequeueQueue As New OracleQueue()
oracleDequeueQueue.Connection = oracleConnection

Dim coll As New OracleQueueAgentCollection()
coll.Add(New OracleQueueAgent("Bob", "MESSAGE_QUEUE"))

' listening only for 60 seconds instead of blocking thread forever
Dim agent As OracleQueueAgent = oracleDequeueQueue.Listen(coll, 60)

Console.WriteLine("The following consumer received a message: {0}", agent.Name)
oracleDequeueQueue.QueueName = agent.Address
oracleDequeueQueue.DequeueOptions.ConsumerName = agent.Name
Console.WriteLine("The message: {0}", oracleDequeueQueue.Dequeue().StringPayload)

oracleQueueAdmin.StopQueue()
oracleQueueAdmin.DropQueue()
oracleQueueTable.DropQueueTable()

oracleConnection.Close()

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

OracleQueue Class
OracleQueue Members
Overload List

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