RestAssured

REST Assured is the de facto standard Java domain-specific language (DSL) for testing RESTful APIs. It simplifies testing of REST-based services by allowing you to write tests in a given-when-then style that is both expressive and integrates perfectly with standard Java testing frameworks like JUnit and TestNG. It abstracts away the low-level code of HTTP clients, enabling you to focus on the behavior of your API. With its fluent interface, you can easily specify request details (headers, params, body) and make powerful assertions on the response.

It's ideal for Java development teams who want a code-based, library-style approach to API testing that lives directly within their project's codebase, enabling tight integration with build tools and fostering practices like testing as code.