Pagination and sorting are crucial features for APIs that return large datasets. They allow clients to retrieve only a portion of the data and specify the order in which it should be returned. In this blog post, we will explore how to document pagination and sorting features in Java Spring REST Docs to provide clear and concise API documentation.

What is Java Spring REST Docs?

Java Spring REST Docs is a framework that helps in creating documentation for RESTful APIs. It integrates seamlessly with the Spring ecosystem to generate accurate and up-to-date API documentation. It allows developers to write documentation as tests, ensuring that the documentation stays in sync with the actual API implementation.

Documenting Pagination

To document pagination, we need to include information about the request parameters that control the page size and page number. Here’s an example of how to document pagination using Java Spring REST Docs:

// ...

import static org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.*;
import static org.springframework.restdocs.request.RequestDocumentation.*;

// ...

this.mockMvc.perform(get("/api/users")
    .param("page", "1")
    .param("size", "10"))
    .andExpect(status().isOk())
    .andDo(document("users",
        requestParameters(
            parameterWithName("page").description("The page number"),
            parameterWithName("size").description("The number of items per page")
        )
    ));

In the above example, we use param() method to add pagination parameters to the request. Then, we use the document() method to document the request parameters using requestParameters().

Documenting Sorting

Sorting allows clients to specify the order in which the API should return the results. We can document sorting by including information about the sorting parameter in the API documentation. Here’s an example of how to document sorting:

// ...

this.mockMvc.perform(get("/api/users")
    .param("sort", "firstName,asc"))
    .andExpect(status().isOk())
    .andDo(document("users",
        requestParameters(
            parameterWithName("sort").description("Sort the results by a field")
        )
    ));

In the above code snippet, we include the sort parameter in the request using param() method. Then, we use the document() method to document the request parameter using requestParameters().

Conclusion

Documenting pagination and sorting features in an API is crucial for the clients to understand how to use these features effectively. By using Java Spring REST Docs, we can easily generate accurate and up-to-date API documentation that includes information about pagination and sorting. This documentation not only helps developers understand how to use the API but also ensures that the documentation remains in sync with the actual implementation. #api #documentation