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Differentiation of Provided Interfaces

Figure 3.10: The same signature is provided via two interfaces
Image cm-cc-same-signature-provided-01

The PCM has special requirements for provided interfaces of components. If a component (independent from its component type) provides interfaces which have overlapping signatures (such as a() in figure 3.10) the components must be able to provide individual services for every provided interface. This means that the effect of the call of IA.a() (usually) is different from the call of IB.a().

However, some programming languages such as the Java programming language do not provide such a feature for provided class interfaces. If one signature occurs at multiple interfaces, the implementing class is not able to differentiate by the called interfaces. Especially if a simple 1:1 mapping from components to classes is implemented, this should be taken into account.



Snowball 2007-03-16