Can Spring Data REST's QueryDSL integration be used to perform more complex queries?

Question

I\'m currently building a REST API in which I want clients to easily filter on most properties of a specific entity. Using QueryDSL in combination with Spring Data REST (an

Answer 1

As it was posted in some comment I also had the need to have different behaviour according to the field name creationDateFrom and creationDateTo. In order to make it work I did the following:

First I added the @QueryEntity annotation and two more fields to my entity class. The fields were annotated with:

• @Transient so the fields are not persisted
• @Getter(value = AccessLevel.PRIVATE) as we are using Lombok, the annotation hides the field from the response body
• @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) takes care of the format for parsing the date on the url query parameter

---

@QueryEntity
@Entity
public class MyEntity implements Serializable {
  ...

  @Column(updatable = false)
  @DateTimeFormat(iso = DateTimeFormat.ISO.DATE)
  private Date creationDate;

  @Transient
  @Getter(value = AccessLevel.PRIVATE)
  @DateTimeFormat(iso = DateTimeFormat.ISO.DATE)
  private Date creationDateTo;

  @Transient
  @Getter(value = AccessLevel.PRIVATE)
  @DateTimeFormat(iso = DateTimeFormat.ISO.DATE)
  private Date creationDateFrom;

  ...
}  

Then I changed the way of generating the querydsl classes from JPAAnnotationProcessor to QuerydslAnnotationProcessor. This way fields annotated with @Transient are still generated on QMyEntity but are not persisted. Plugin configuration in pom:

    com.mysema.maven
    apt-maven-plugin
    1.1.3
    
        
            generate-sources
            
                process
            
            
                target/generated-sources/annotations
                com.querydsl.apt.QuerydslAnnotationProcessor
            
        
    

Finally I extended the QuerydslBinderCustomizer and customized the bindings related with the creationDateFrom and creationDateTo but applying the right logic over creationDate

@Override
default void customize(QuerydslBindings bindings, QMyEntity root) {
    bindings.bind(root.creationDateFrom).first((path, value) -> 
                                                root.creationDate.after(value));
    bindings.bind(root.creationDateTo).first((path, value) ->
                                               root.creationDate.before(value));
}

With all of this you can do date range queries using one, both or none of the criterias:

http://localhost:8080/myentities?creation_date_to=2017-05-08
http://localhost:8080/myentities?creation_date_from=2017-01-01
http://localhost:8080/myentities?creation_date_from=2017-01-01&creation_date_to=2017-05-08