Spring Data JPA: Query by Example?

Question

Using Spring Data JPA can I do a query by example where a particular entity instance is used as the search criteria?

For example (no pun intended), if I have a Person entity that looks like:

@Entity public class Person {   private String firstName;   private String lastName;   private boolean employed;   private LocalDate dob;   ... } 

I could find all employed persons with a last name of Smith born on January 1, 1977 with an example:

Person example = new Person(); example.setEmployed(true); example.setLastName("Smith"); example.setDob(LocalDate.of(1977, Month.JANUARY, 1)); List<Person> foundPersons = personRepository.findByExample(example); 

Answer 1

This is now possible with Spring Data. Check out http://docs.spring.io/spring-data/jpa/docs/current/reference/html/#query-by-example

Person person = new Person();                          person.setLastname("Smith");                           Example<Person> example = Example.of(person); List<Person> results = personRepository.findAll(example); 

Note that this requires very recent 2016 versions

    <dependency>         <groupId>org.springframework.data</groupId>         <artifactId>spring-data-jpa</artifactId>         <version>1.10.1.RELEASE</version>            </dependency>     <dependency>         <groupId>org.springframework.data</groupId>         <artifactId>spring-data-commons</artifactId>         <version>1.12.1.RELEASE</version>     </dependency> 

see https://github.com/paulvi/com.example.spring.findbyexample