Hibernate Search Order by child-count

Question

Consider:

@Indexed
@Entity
public class TParent  implements java.io.Serializable {

 .....
 private Set TChildSet = new HashSet(0);

         


        

Answer 1

In hibernate search, you can make a custom Bridge for this purpose.

Something along the lines of:

@FieldBridge(impl = com.myco.myapp.CollectionCountBridge.class)
@ContainedIn
@OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY, mappedBy="TParent")
public Set<TChild> getTChildSet() {
     return this.TChildSet;
}

With the custom bridge implementation:

public class CollectionCountBridge extends PaddedIntegerBridge {

    @Override
    public String objectToString(Object object) {
        if (object == null || (!(object instanceof Collection))) {
            return null;
        }
        Collection<?> coll = (Collection<?>) object;
        return super.objectToString(coll.size());
    }
}