The second program in the direct example, direct_producer.cpp, publishes messages to the amq.direct exchange using the routing key routing_key.

First, create a message and set a routing key. The same routing key will be used for each message we send, so you only need to set this property once.

message.getDeliveryProperties().setRoutingKey("routing_key");

Now send some messages:

for (int i=0; i<10; i++) {
  stringstream message_data;
  message_data << "Message " << i;

  message.setData(message_data.str());
  session.messageTransfer(arg::content=message, arg::destination="amq.direct");
}

Send a final message to indicate termination.

message.setData("That's all, folks!");
session.messageTransfer(arg::content=message, arg::destination="amq.direct");