org.hibernate.search.mapper.pojo.mapping.definition.annotation

Annotation Type IndexedEmbedded

@Documented
 @Target(value={METHOD,FIELD})
 @Retention(value=RUNTIME)
public @interface IndexedEmbedded

Maps a property to an object field whose fields are the same as those defined in the property type.

This allows search queries on a single index to use data from multiple entities.

For example, let's consider this (incomplete) mapping:

 {@literal @}Indexed
 public class Book {
     {@literal @}GenericField
     private String title;
     {@literal @}IndexedEmbedded
     private List<Author> authors;
 }
 public class Author {
     {@literal @}GenericField
     private String firstName;
     {@literal @}GenericField
     private String lastName;
     private List<Book> books;
 }
 

The names of authors are stored in different objects, thus by default they would not be included in documents created for Book entities. But we added the @IndexedEmbedded annotation to the authors property, so Hibernate Search will embed this data in a authors field of documents created for Book entities.

How exactly this embedding will happen depends on the configured storage type. Let's consider this representation of the book "Levianthan Wakes":

• title = Levianthan Wakes
• authors =
  • (first element)
    • firstName = Daniel
    • lastName = Abraham
  • (second element)
    • firstName = Ty
    • lastName = Frank

With the default flattened storage type (more efficient), the structure will be a little different from what one would expect:

• title = Levianthan Wakes
• authors.firstName =
  • (first element) Daniel
  • (second element) Ty
• authors.lastName =
  • (first element) Abraham
  • (second element) Frank

To get the original structure, the nested storage type must be used, but this has an impact on performance and how queries must be structured. See the reference documentation for more information.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
ContainerExtraction	extraction
String[]	includePaths The paths of index fields from the indexed-embedded element that should be embedded.
int	maxDepth The max recursion depth for indexed-embedded processing.
String	prefix
ObjectFieldStorage	storage

Element Detail

prefix

public abstract String prefix

Returns:

The prefix used when embedding. Defaults to <property name>., meaning an object field with the same name as the property will be defined in the parent document to host the value of the child document.

Default:

""

includePaths

public abstract String[] includePaths

The paths of index fields from the indexed-embedded element that should be embedded.

This takes precedence over maxDepth().

By default, if neither includePaths nor maxDepth() is defined, all index fields are included.

Returns:

The paths of index fields to include explicitly. Provided paths must be relative to the indexed-embedded element, i.e. they must not include the prefix().

Default:

{}

maxDepth

public abstract int maxDepth

The max recursion depth for indexed-embedded processing.

maxDepth is the number of `@IndexedEmbedded` that will be traversed and for which all fields of the indexed-embedded element will be included, even if these fields are not included explicitly through includePaths:

• maxDepth=0 means fields of the indexed-embedded element are not included, nor is any field of nested indexed-embedded elements, unless these fields are included explicitly through includePaths().
• maxDepth=1 means fields of the indexed-embedded element are included, but not fields of nested indexed-embedded elements, unless these fields are included explicitly through includePaths().
• And so on.

The default value depends on the value of the includePaths() attribute: if includePaths() is empty, the default is Integer.MAX_VALUE (no limit) if includePaths() is not empty, the default is 0 (only include fields included explicitly).

Returns:

The max depth size.

Default:

-1

storage

public abstract ObjectFieldStorage storage

Returns:

The storage strategy of the object field created for this indexed-embedded.

See Also:

ObjectFieldStorage

Default:

org.hibernate.search.engine.backend.document.model.dsl.ObjectFieldStorage.DEFAULT

extraction

public abstract ContainerExtraction extraction

Returns:

A definition of container extractors to be applied to the property, allowing the definition of an indexed-embedded for container elements. This is useful when the property is of container type, for example a Map<TypeA, TypeB>: defining the extraction as @ContainerExtraction(BuiltinContainerExtractors.MAP_KEY) allows referencing map keys instead of map values. By default, Hibernate Search will try to apply a set of extractors for common container types.

See Also:

ContainerExtraction

Default:

@org.hibernate.search.mapper.pojo.extractor.mapping.annotation.ContainerExtraction