Setting/Getting Parameters
A key feature of messages is the ability to set message parameters.
There are two types of parameters:
● Predefined Parameters: A set of parameters for which the RTMFMessage class provides getters and setters. Some predefined parameters are automatically set in some cases.
● Customer Parameters: A parameter that you can create for the RTMFMessage object.
Predefined Parameters
A message contains the following predefined parameters:
● Action
● Event
The event parameter is automatically set when the publishEvent() method is called. The value is the name of the event that was triggered.
● From
● Destination
The destination parameter is automatically set when a message is sent to an RTMF service, for example, by calling publishToTopic() or sendToQueue(). The value is the name of the service.
The RTMFMessage class defines setters and getters for these parameters. You cannot retrieve the values of predefined parameters by calling getParamValue().
An RTMF service that registers to receive messages sent to another service can use only predefined parameters to create a filter. For more information, see Registering for Messages Sent to Another Service.
Custom Parameters
You can add custom parameters to the message, as follows:
RTMFMessage message = RTMFMessageFactory
.getMessage(RTMFMessageType.RTMFMessageType);
message.putParam("param","value");
You can retrieve parameters as follows:
String myParam = message.getParamValue("param");
Adding a List of Values
In addition to a String, you can define a Listof values, and add this as a single parameter, as follows:
RTMFMessage message = RTMFMessageFactory.
getMessage(RTMFMessageType.RTMFMessageType);
List myValueList = new Vector();
myValueList.add("value1");
myValueList.add("value2");
message.putParam("paramWithValueList", myValueList);
The following retrieves a parameter that is a List:
List myParamValues = message.getParamValues("paramWithValueList");
If you retrieve a String parameter as a List, a List with a single string is returned.
If you retrieve a List as a String, the first string in the List is returned.