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Optional Parameters in Java 8 Lambda Expressions

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Optional Parameters in Java 8 Lambda Expressions

· Java Zone
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Navigate the Maze of the End-User Experience and pick up this APM Essential guide, brought to you in partnership with CA Technologies

Yeah, they don't really exist, but we can use polymorphism, method overloading and default methods instead to make it a bit more convenient to use our APIs.

As an example, here's an event bus implementation where I can register event handlers with an optional header parameter.

  Bus bus = new Bus();
  bus.register(event -> System.out.println("I gots an event"));
  bus.register((event,header) -> System.out.println("I gots an event w/ header"));

Here are the dirty details on how you can do this (and - when dispatching - events, use default methods to avoid type coercion.

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Topics:
java8 ,lambda

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