Let's make a contract: the art of designing a Java API by Mario Fusco

Designing a successful Java API requires a contract that's intuitive, understandable, and easily discoverable.

Key takeaways

The art of designing a Java API is crucial to its success.
The main goal of an API is to provide a contract that defines how a service works and how users interact with it.
The API should be intuitive, understandable, learnable, and discoverable.
Avoidance of boolean arguments and null values is crucial for a good API.
Fluent APIs are nice but should be used judiciously, as they can lead to verbose code and should be combined with other design principles.
The trade-off is between providing more power to users versus providing a simple API.
The return type of a method should be as weak as possible to provide users with the most possible freedom.
It is essential to document the API clearly, including the domain model.
Duplication of effort and underestimating the value of documentation are common mistakes.
It is essential to consider the future-proof goal and avoid adding features without considering the impact on the API.
Consistency and discoverability are crucial in an API.
Making good use of static factory methods, fluent APIs, and navigator APIs is important.
It is crucial to have a clear understanding of the API and how it will evolve to prevent runtime errors.
The use of checked exceptions and unchecked exceptions is a complex issue in Java.

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