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Using Optional as a better alternative to null

NullPointerException - We examine a field of an object, perhaps to determine whether its value is one of two expected forms, only to instead find we're examining not an object but a null pointer that promptly raise that annoying NullPointerException

Problems with null

  • It's a source of error. NullPointerException is by far the most common exception in Java.

  • It bloats your code. It worsens readability by making it necessary to fill your code with often deeply nested null checks.

  • It creates a hole in the type system. null carries no type or other information, meaning it can be assigned to any reference type. This is a problem because, when it's propagated to another part of the system, you have no idea what null was initially supposed to be.

Optional class

Using optionals consistently disambiguates beyond any doubt the case of a value that can be structurally missing from the case of a values that's absent only because of a bug in your algorithm or a problem in your data.

Patterns for adopting Optional

Creating Optional Objects

to be continued...