How do you know if a class implements an interface?

When a class implements an interface, you can think of the class as signing a contract, agreeing to perform the specific behaviors of the interface . If a class does not perform all the behaviors of the interface, the class must declare itself as abstract. A class uses the implements keyword to implement an interface.

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Using Reflection you can invoke the Class. getInterfaces() method which returns an Array of Interfaces that your class implements. You may also want to recurse on the interfaces extended by these interfaces.

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