Spring Boot 4 Microservices & REST APIs · Lesson

Dynamic Queries with Specifications

Build flexible queries programmatically.

The Problem with Static Queries

When users can filter by many optional fields, writing one query method per combination explodes quickly.

Spring Data Specifications let you build queries dynamically at runtime based on which filters are present.

Extend JpaSpecificationExecutor on your repository to enable Specification-based queries.

public interface UserRepository
    extends JpaRepository<User, Long>,
            JpaSpecificationExecutor<User> {
}