How do you implement filtering and sorting in REST APIs with Spring Boot?

Table of Contents

• Introduction
• Implementing Filtering and Sorting with Spring Boot
  • 1. Using Query Parameters for Filtering and Sorting
    • Example: Filtering and Sorting in REST API
    • Example Request:
  • 2. Using Spring Data JPA for Advanced Filtering and Sorting
    • Example: Repository with Sorting and Filtering
  • 3. Using Pageable for Pagination, Filtering, and Sorting
    • Example: Pagination, Sorting, and Filtering with Pageable
    • Example Request:
• Practical Example: Filtering and Sorting Products
• Conclusion

Introduction

When building REST APIs with Spring Boot, implementing filtering and sorting mechanisms can significantly enhance the flexibility and usability of the API. Filtering allows users to retrieve only the data they need, while sorting enables ordering of results based on specific fields. In this guide, we will cover how to implement filtering and sorting in Spring Boot using query parameters, and how to leverage Spring Data JPA for more advanced querying capabilities.

Implementing Filtering and Sorting with Spring Boot

1. Using Query Parameters for Filtering and Sorting

Spring Boot allows you to filter and sort data using query parameters in the URL. This approach is simple and works well for small datasets or basic filtering and sorting needs.

Example: Filtering and Sorting in REST API

Example Request:

In this example, query parameters are used to filter products by name and price, and to sort the results by a specific field (price in descending order).

2. Using Spring Data JPA for Advanced Filtering and Sorting

Spring Data JPA provides a powerful way to implement filtering and sorting through repository methods. You can define custom queries using @Query annotations, or leverage method query derivation based on property names.

Example: Repository with Sorting and Filtering

Here, the ProductRepository defines methods for filtering products by name and price, while allowing sorting based on a Sort object.

3. Using Pageable for Pagination, Filtering, and Sorting

To implement pagination along with filtering and sorting, you can use Spring Data JPA’s Pageable interface. This allows clients to specify page numbers and page sizes for large datasets.

Example: Pagination, Sorting, and Filtering with Pageable

Example Request:

In this example, pagination is combined with filtering and sorting. The client can specify the page number (page), page size (size), filter by name and price, and specify the sorting field and direction.

Practical Example: Filtering and Sorting Products

1. Filtering by Name and Sorting by Price:

   This would return a list of products with the name "Laptop", sorted by price in descending order.

2. Paginated Results with Filtering:

   This would return the second page (page number 1, with 10 items per page) of products that cost 799.99, sorted by name in ascending order.

Conclusion

Implementing filtering and sorting in REST APIs with Spring Boot enhances the flexibility and performance of your APIs. Using query parameters or Spring Data JPA’s Sort and Pageable interfaces, you can easily allow clients to filter and sort large datasets. By combining filtering, sorting, and pagination, you can optimize the response times and improve the usability of your API for end-users.