Message objects that may contain different elements depending on the underlying messaging protocol. This is different from Datagrams that are assumed always to be just blocks of binary data. An adapter specification for a given messaging protocol may define further interfaces derived from the Message interfaces included in this generic specification. The wireless messaging protocols that are accessed via this API are typically of store-and-forward nature, unlike network layer datagrams. Thus, the messages will usually reach the recipient, even if the recipient is not connected at the time of sending the message. This may happen a significant time later if the recipient is disconnected for a long time. Sending, and possibly also receiving, these wireless messages, typically involves a financial cost to the end user that cannot be neglected. Therefore, applications should not send many messages unnecessarily.
This interface contains the functionality common to all messages. Concrete object instances representing a message will typically implement other (sub)interfaces providing access to the content and other information in the message which is dependent on the type of the message.
Object instances implementing this interface are just containers for the data that is passed in. The setAddress() method just sets the value of the address in the data container without any checking whether the value is valid in any way.
| |