Spring Data Elasticsearch Inheritance - spring

Question

Is there any way to make a super-class document (e.g. index name = user) and create two child classes (Admin, Guest) to save all this to user index but with different fields? E.g. Add to super-class field type and based on this field fetch right entity? ELK 7.19, Spring Data 4.3.1.

Answer 1

You can do that. Make the base class abstract. I have this in a test setup with the following classes:
#Document(indexName = "type-hints")
public abstract class BaseClass {
#Id
private String id;
#Field(type = FieldType.Text)
private String baseText;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getBaseText() {
return baseText;
}
public void setBaseText(String baseText) {
this.baseText = baseText;
}
#Override
public String toString() {
return "BaseClass{" +
"id='" + id + '\'' +
", baseText='" + baseText + '\'' +
'}';
}
}
public class DerivedOne extends BaseClass {
#Field(type = FieldType.Text)
private String derivedOne;
public String getDerivedOne() {
return derivedOne;
}
public void setDerivedOne(String derivedOne) {
this.derivedOne = derivedOne;
}
#Override
public String toString() {
return "DerivedOne{" +
"derivedOne='" + derivedOne + '\'' +
"} " + super.toString();
}
}
public class DerivedTwo extends BaseClass {
#Field(type = FieldType.Text)
private String derivedTwo;
public String getDerivedTwo() {
return derivedTwo;
}
public void setDerivedTwo(String derivedTwo) {
this.derivedTwo = derivedTwo;
}
#Override
public String toString() {
return "DerivedTwo{" +
"derivedTwo='" + derivedTwo + '\'' +
"} " + super.toString();
}
}
interface TypeHintRepository extends ElasticsearchRepository<BaseClass, String> {
SearchHits<? extends BaseClass> searchAllBy();
}
#RestController
#RequestMapping("/typehints")
public class TypeHintController {
private static final Logger LOGGER = LoggerFactory.getLogger(TypeHintController.class);
private final TypeHintRepository repository;
public TypeHintController(TypeHintRepository repository) {
this.repository = repository;
}
#GetMapping
public void test() {
List<BaseClass> docs = new ArrayList<>();
DerivedOne docOne = new DerivedOne();
docOne.setId("one");
docOne.setBaseText("baseOne");
docOne.setDerivedOne("derivedOne");
docs.add(docOne);
DerivedTwo docTwo = new DerivedTwo();
docTwo.setId("two");
docTwo.setBaseText("baseTwo");
docTwo.setDerivedTwo("derivedTwo");
docs.add(docTwo);
repository.saveAll(docs);
SearchHits<? extends BaseClass> searchHits = repository.searchAllBy();
for (SearchHit<? extends BaseClass> searchHit : searchHits) {
LOGGER.info(searchHit.toString());
}
}
}