Treat no attributes annotated with @ConvertedWith as association.

[myfrontpocket]

With 6.0.5, I'm trying to work through some OGM-to-SDN migration, and I think I may have come across an issue with @ConvertWith, but I'm not sure if my usage is correct or not.

I have a repository test that tests a findById method, but as the test spins up and sets up I get an error: java.lang.IllegalStateException: Required identifier property not found for class ...

The generalized code:

@Node
public class DomainOne {

	@Id
	@Property
	@GeneratedValue(GeneratedValueStrategy.class)
	private String id;
	
	@ConvertWith(converter = DomainTwoConverter.class)
	private DomainTwo domainTwo = new DomainTwo();
}

@Getter
@Setter
public class DomainTwo {
	
	private boolean aBooleanValue;
	private Long aLongValue;

	public DomainTwo() {
		aLongValue = 0;
	}

	public DomainTwo(boolean aBooleanValue, Long aLongValue) {
		this.aBooleanValue = aBooleanValue;
		this.aLongValue = aLongValue;
	}

}

@Repository
public interface DomainOneRepository extends Neo4jRepository<DomainOne, String> {
	
	@Query("MATCH (domainOne:DomainOne { id: $id })"
		// plus OPTIONAL MATCH statements
		"RETURN domainOne;")
	Optional<DomainOne> findById(String id);
}


public DomainTwoConverterClass implements Neo4jPersistentPropertyConverter<DomainTwoConverterClass> {

	private static final A_BOOLEAN_VAUE = "aBooleanValue";
	private static final A_LONG_VALUE = "aLongValue";

	@Override
	public Value write(DomainTwo source) {
		Map<String, Object> values = Map.of(
			A_BOOLEAN_VAUE, source.aBooleanValue(),
       		A_LONG_VALUE, source.aLongValue()
    	);
    	
    	return Values.value(values);
	}

	@Override
	public DomainTwo read(Value source) {
		boolean aBooleanValue = Optional.ofNullable(source.asMap().get(A_BOOLEAN_VALUE))
			.filter(obj -> obj instanceof Boolean)
			.map(Boolean.class::cast)
			.orElse(false);

		Long aLongValue = Optional.ofNullable(source.get(A_LONG_VALUE))
        	.filter(obj -> Number.class.isAssignableFrom(obj.getClass()))
        	.map(obj -> ((Number) obj).longValue())
        	.orElse(0L);

        return new DomainTwo(aBooleanValue, aLongValue);

	}
}

[michael-simons]

Would you mind sharing your GeneratedValueStrategy that you are using vor @GeneratedValue? Thanks.

[myfrontpocket]

  private static final Integer ID_LENGTH = 8;
  private static final Pattern ID_REGEX = Pattern.compile("^[A-Za-z0-9]{8}$");
  private static final String LOWER = "abcdefghijklmnopqrstuvwxyz";
  private static final String UPPER = LOWER.toUpperCase();
  private static final String NUMERIC = "0123456789";

  @Override
  public Object generateId(Object object) {
    if (SomeObject.class.isAssignableFrom(object.getClass())) {
      SomeObject someObject = (SomeObject) object;
      if (!Optional.ofNullable(someObject.getId()).isPresent()) {
        return Optional.ofNullable(generateId())
            .filter(id -> isValidId(id))
            .orElseThrow(() -> new IllegalStateException(
            String.format("Failed to generate id for object: <%S>", someObject.toString())));
      } else {
        return someObject.getId();
      }
    }
    throw new IllegalStateException("Object does not extend SomeObject. No identifier generated.");
  }

  public String generateId() {
    String source = StringUtils.join(UPPER.concat(LOWER).concat(NUMERIC));
    StringBuilder output = new StringBuilder(ID_LENGTH);

    ThreadLocalRandom rand = ThreadLocalRandom.current();

    while (output.length() < ID_LENGTH) {
      output.append( source.charAt( rand.nextInt(source.length())));
    }
    return output.toString();
  }

[michael-simons]

Thanks. I just wanted to make sure that this is the reason for your issues.

So the problem is you cannot use ConvertWith to create map of properties. You must use CompositeProperty for that

public final class DomainTwoCompositePropertyConverter implements Neo4jPersistentPropertyToMapConverter<String, DomainTwo> {

	private static final String A_BOOLEAN_VALUE = "aBooleanValue";
	private static final String A_LONG_VALUE = "aLongValue";

	@Override
	public Map<String, Value> decompose(DomainTwo property, Neo4jConversionService neo4jConversionService) {
		Map<String, Value> values = new HashMap<>();
		values.put(A_BOOLEAN_VALUE, Values.value(property.isABooleanValue()));
		values.put(A_LONG_VALUE, Values.value(property.getALongValue()));
		return values;
	}

	@Override
	public DomainTwo compose(Map<String, Value> source, Neo4jConversionService neo4jConversionService) {
		boolean aBooleanValue = Optional.ofNullable(source.get(A_BOOLEAN_VALUE))
				.map(Value::asBoolean)
				.orElse(false);

		Long aLongValue = Optional.ofNullable(source.get(A_LONG_VALUE))
				.map(Value::asLong)
				.orElse(0L);

		return new DomainTwo(aBooleanValue, aLongValue);
	}
}

using like

this

@CompositeProperty(converter = DomainTwoCompositePropertyConverter.class)
private DomainTwo customConverterDefaultPrefix = new DomainTwo();

this will however generate a prefix, which is inline with Neo4j-OGM's CompositeAttributeConverter, so that shouldn't be an issue in your migration.

[michael-simons]

Here's test code for the example above

DomainOne domainOne = new DomainOne();
domainOne.setCustomConverterDefaultPrefix(new DomainTwo(true, 4711L));
domainOne = domainOneRepository.save(domainOne);

try (Session session = driver.session()) {
	Node node = session
			.run("MATCH (n:DomainOne {id: $id}) RETURN n", Collections.singletonMap("id", domainOne.getId()))
			.single().get(0).asNode();
	assertThat(node.get("customConverterDefaultPrefix.aBooleanValue").asBoolean()).isTrue();
	assertThat(node.get("customConverterDefaultPrefix.aLongValue").asLong()).isEqualTo(4711L);
}

[myfrontpocket]

Thanks so much! I'll give this a try!

[michael-simons]

Please have a look at this test https://github.com/spring-projects/spring-data-neo4j/blob/master/src/test/java/org/springframework/data/neo4j/integration/issues/gh2168/Gh2168IT.java#L65-L118 added via 1fb0945

thank you!