In Unified Modeling Language (UML) sequence diagrams, you can set
a message signature by assigning an operation to it. When you create a message,
the operation on the target interaction instance is created automatically
and you are prompted to name the newly created operation.
You must have a sequence diagram that contains at least two lifelines
with messages open in the diagram editor. The property of the target lifeline
to which you add the operation must be a class or interface type.
To assign an operation to a message:
- In the Package Explorer or Project
Explorer view, click and drag a Java™ class or interface to a lifeline in
the interaction frame. The interaction instance now represents
that class.
- In the Package Explorer or Project
Explorer view, click and drag an operation to a message in the
interaction frame. The operation must belong to the class that is assigned
to the target instance.