Package org.osgi.service.wireadmin

Interface Envelope

All Known Implementing Classes:
BasicEnvelope
public interface Envelope
Identifies a contained value. An Envelope object combines a status value, an identification object and a scope name. The Envelope object allows the use of standard Java types when a Producer service can produce more than one kind of object. The Envelope object allows the Consumer service to recognize the kind of object that is received. For example, a door lock could be represented by a Boolean object. If the Producer service would send such a Boolean object, then the Consumer service would not know what door the Boolean object represented. The Envelope object contains an identification object so the Consumer service can discriminate between different kinds of values. The identification object may be a simple String object, but it can also be a domain specific object that is mutually agreed by the Producer and the Consumer service. This object can then contain relevant information that makes the identification easier.

The scope name of the envelope is used for security. The Wire object must verify that any Envelope object send through the update method or coming from the poll method has a scope name that matches the permissions of both the Producer service and the Consumer service involved. The wireadmin package also contains a class BasicEnvelope that implements the methods of this interface.

See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    getIdentification()
    Return the identification of this Envelope object.
    String
    getScope()
    Return the scope name of this Envelope object.
    Object
    getValue()
    Return the value associated with this Envelope object.

  • Method Details

    • getValue

      Object getValue()
      Return the value associated with this Envelope object.
      Returns:
      the value of the status item, or null when no item is associated with this object.

    • getIdentification

      Object getIdentification()
      Return the identification of this Envelope object. An identification may be of any Java type. The type must be mutually agreed between the Consumer and Producer services.
      Returns:
      an object which identifies the status item in the address space of the composite producer, must not be null.

    • getScope

      String getScope()
      Return the scope name of this Envelope object. Scope names are used to restrict the communication between the Producer and Consumer services. Only Envelopes objects with a scope name that is permitted for the Producer and the Consumer services must be passed through a Wire object.
      Returns:
      the security scope for the status item, must not be null.