Making Date queries on MongoDB using JSON on SpringDataMongoDB - spring-boot

I'm having some trouble making MongoDB Date queries using #Query annotation on SpringDataMongoDB on a project created using JHipster.
Since JHipster was used to create the project most of the queries were created using Spring Data query builder mechanism and for more refined queries, instead of using Type-safe Query methods I decided to stick with JHipster's standard configuration and make personalized queries using #Query annotation that allows the creation of MongoDBJSON queries.
However, I can't reference in my Json queries any entity field of type Date or LocalDate.
I tried to adopt as a solution the answer from this thread without success.
Query attempts
#Repository
public interface CourseClassRepository extends MongoRepository<CourseClass, String> {
// WORKS - query with `endDate` directly constructed by Spring Data
// This sollution however isn't enought, since 'experience_enrollments.device_id' cannot be used as a parameter
List<CourseClass> findAllByInstitutionIdAndEndDateIsGreaterThanEqual(Long institutionId, LocalDate dateLimit);
// Using #Query to create a JSON query doesn't work.
// apparently data parameter cannot be found. This is weird, considering that in any other #Query created the parameter is found just fine.
// ERROR: org.bson.json.JsonParseException: Invalid JSON input. Position: 124. Character: '?'
#Query(" { 'experience_enrollments.device_id' : ?0, 'institution_id': ?1, 'end_date': { $gte: { $date: ?2 } } } ")
List<CourseClass> findAllByExperienceDeviceAndInstitutionIdAndEndDate(String deviceId, Long institutionId, Date dateLimit);
// Adopting the stackoverflow answer mentioned above also throws an error. I belive that this error is related to the fact that '?2' is being interpreted as a String value and not as reference to a parameter
// ERROR: org.bson.json.JsonParseException: Failed to parse string as a date
#Query(" { 'experience_enrollments.device_id' : ?0, 'institution_id': ?1, 'end_date': { $gte: { $date: '?2' } } } ")
List<CourseClass> findAllByExperienceDeviceAndInstitutionIdAndEndDate(String deviceId, Long institutionId, Date dateLimit);
// Even hardcoding the date parameter, the query throws an error
// ERROR: org.bson.codecs.configuration.CodecConfigurationException: Can't find a codec for class java.time.ZonedDateTime.
#Query(" { 'experience_enrollments.device_id' : ?0, 'institution_id': ?1, 'end_date': { '$gte': { '$date': '2015-05-16T07:55:23.257Z' } } }")
List<CourseClass> findAllByExperienceDeviceAndInstitutionIdAndEndDate(String deviceId, Long institutionId);
}
Database Configurations
#Configuration
#EnableMongoRepositories("br.com.pixinside.lms.course.repository")
#Profile("!" + JHipsterConstants.SPRING_PROFILE_CLOUD)
#Import(value = MongoAutoConfiguration.class)
#EnableMongoAuditing(auditorAwareRef = "springSecurityAuditorAware")
public class DatabaseConfiguration {
#Bean
public MongoCustomConversions customConversions() {
List<Converter<?, ?>> converters = new ArrayList<>();
converters.add(DateToZonedDateTimeConverter.INSTANCE);
converters.add(ZonedDateTimeToDateConverter.INSTANCE);
return new MongoCustomConversions(converters);
}
}
Date converters
public static class DateToZonedDateTimeConverter implements Converter<Date, ZonedDateTime> {
public static final DateToZonedDateTimeConverter INSTANCE = new DateToZonedDateTimeConverter();
private DateToZonedDateTimeConverter() {
}
#Override
public ZonedDateTime convert(Date source) {
return source == null ? null : ZonedDateTime.ofInstant(source.toInstant(), ZoneId.systemDefault());
}
}
public static class ZonedDateTimeToDateConverter implements Converter<ZonedDateTime, Date> {
public static final ZonedDateTimeToDateConverter INSTANCE = new ZonedDateTimeToDateConverter();
private ZonedDateTimeToDateConverter() {
}
#Override
public Date convert(ZonedDateTime source) {
return source == null ? null : Date.from(source.toInstant());
}
}

Turns out that, as mentioned by Christoph Strobl, the behavior was, in fact, a bug. So it won't be necessary to worry about that in a future version of Spring Data MongoDB. Until there, I'm sharing my solution.
Since I was unable to use MongoDBJSon to create the query, I used the MongoTemplate and everything was just fine.
import org.springframework.data.mongodb.core.MongoTemplate;
import static org.springframework.data.mongodb.core.query.Criteria.where;
import static org.springframework.data.mongodb.core.query.Query.query;
#Autowired
public MongoTemplate mongoTemplate;
public List<CourseClass> findEnrolledOnExperienceDeviceWithMaxEndDateAndInstitutionId(String deviceId, LocalDate endDate, Long institutionId) {
return mongoTemplate.find(query(
where("experience_enrollments.device_id").is(deviceId)
.and("institution_id").is(institutionId)
.and("end_date").gte(endDate)), CourseClass.class);
}

Related

how to get tuple with average(xxx) by spring data jpa specification?

I want to get the List<Map<String,Object>>returned by query like this:
[{production:{the object}, avgscore:123}, {production:{other object},avgscore:456}, ...]
I can get it by this :
public interface ProductionRepository extends PagingAndSortingRepository<Production, Long> {
#Query("SELECT p as productions,avg(c.score) as avgscore FROM ......")
List<Map<String,Object>> findSorted(......);
}
but now I try to use Specification, and I done the specification:
Specification specification = new Specification() {
#Override
public Predicate toPredicate(Root root1, CriteriaQuery query, CriteriaBuilder cb) {
.......
.......
if (date2 != null) {
Predicate endTimeP = cb.lessThanOrEqualTo(root.get(Production_.productDate), date2);
predicates.add(endTimeP);
}
query.groupBy(root.get(Production_.id)).orderBy(cb.desc(cb.avg(commentJoin.get(Comment_.score))));
Predicate[] predicates1 = new Predicate[predicates.size()];
predicates.toArray(predicates1);
query.multiselect(root.alias("production"),
cb.avg(commentJoin.get(Comment_.score)).as(Double.class).alias("avgscore"));
return cb.and(predicates1);
}
and then I use this to findAll:
return specificationRepo.findAll(specification);
the repository is:
#Repository
public interface SpecificationRepository extends PagingAndSortingRepository<Production, Long>,
JpaSpecificationExecutor {
List<Map<String,Object>> findAll(Specification specification);
}
BUT, the findAll() only return List<Production> , no matter how I change the return type, it always return List<production> , not List<Map<String,Object>> I wanted.
it it bind to the Production in PagingAndSortingRepository<Production, Long>. If I delete this and only have JpaSpecificationExecutor, spring will not seem it as a #Repository; The Production position must be a #Entity, I can not change it to a custom java thing having Production and avgscore.
I have searched long time, but still didn't find how to solve.

Jackson #JsonFilter is not getting applied when used at field or method level

I am using Spring version 4.3.3 and Jackson version 2.8.3. I am trying to filter out specific fields from an entity bean based on some custom logic that is determined at runtime. The #JsonFilter seems ideal for this type of functionality. The problem is that when I put it at the field or method level, my custom filter never gets invoked. If I put it at the class level, it gets invoked just fine. I don't want to use it at the class level though since then I would need to separately maintain the list of hardcoded field names that I want to apply the logic to. As of Jackson 2.3, the ability to put this annotation at the field level is supposed to exist.
Here is the most basic custom filter without any custom logic yet:
public class MyFilter extends SimpleBeanPropertyFilter {
#Override
protected boolean include(BeanPropertyWriter beanPropertyWriter) {
return true;
}
#Override
protected boolean include(PropertyWriter propertyWriter) {
return true;
}
}
Then I have the Jackson ObjectMapper configuration:
public class MyObjectMapper extends ObjectMapper {
public MyObjectMapper () {
SimpleFilterProvider filterProvider = new SimpleFilterProvider();
filterProvider.addFilter("myFilter", new MyFilter());
setFilterProvider(filterProvider);
}
}
Then finally I have my entity bean:
#Entity
public class Project implements Serializable {
private Long id;
private Long version;
#JsonFilter("myFilter") private String name;
#JsonFilter("myFilter") private String description;
// getters and setters
}
If I move the #JsonFilter annotation to the class level where #Entity is, the filter at least gets invoked, but when it is at the field level like in the example here, it never gets invoked.
I have the same need but after examining the unit tests I discovered that this is not the use-case covered by annotating a field.
Annotating a field invokes a filter on the value of the field not the instance containing the field. For example, imagine you have to classes, A and B, where A contains a field of type B.
class A {
#JsonFilter("myFilter") B foo;
}
Jackson applies "myFilter" to the fields in B not in A. Since your example contains fields of type String, which has no fields, Jackson never invokes your filter.
I have a need to exclude certain fields based on the caller's permissions. For example, an employee's profile may contain his taxpayer id, which is considered sensitive information and should only be serialized if the caller is a member of the Payrole department. Since I'm using Spring Security, I wish to integrate Jackson with the current security context.
public class EmployeeProfile {
private String givenName;
private String surname;
private String emailAddress;
#VisibleWhen("hasRole('PayroleSpecialist')")
private String taxpayerId;
}
The most obvious way to do this is to Jackson's filter mechanism but it has a few limitations:
Jackson does not support nested filters so adding an access filter prohibits using filters for any other purpose.
One cannot add Jackson annotations to existing, third-party classes.
Jackson filters are not designed to be generic. The intent is to write a custom filter for each class you wish to apply filtering. For example, I you need to filter classes A and B, then you have to write an AFilter and a BFilter.
For my use-case, the solution is to use a custom annotation introspector in conjunction with a chaining filter.
public class VisibilityAnnotationIntrospector extends JacksonAnnotationIntrospector {
private static final long serialVersionUID = 1L;
#Override
public Object findFilterId(Annotated a) {
Object result = super.findFilterId(a);
if (null != result) return result;
// By always returning a value, we cause Jackson to query the filter provider.
// A more sophisticated solution will introspect the annotated class and only
// return a value if the class contains annotated properties.
return a instanceof AnnotatedClass ? VisibilityFilterProvider.FILTER_ID : null;
}
}
This is basically a copy SimpleBeanProvider that replaces calls to include with calls to isVisible. I'll probably update this to use a Java 8 BiPredicate to make the solution more general but works for now.
This class also takes another filter as an argument and will delegate to it the final decision on whether to serialize the field if the field is visible.
public class AuthorizationFilter extends SimpleBeanPropertyFilter {
private final PropertyFilter antecedent;
public AuthorizationFilter() {
this(null);
}
public AuthorizationFilter(final PropertyFilter filter) {
this.antecedent = null != filter ? filter : serializeAll();
}
#Deprecated
#Override
public void serializeAsField(Object bean, JsonGenerator jgen, SerializerProvider provider, BeanPropertyWriter writer) throws Exception {
if (isVisible(bean, writer)) {
this.antecedent.serializeAsField(bean, jgen, provider, writer);
} else if (!jgen.canOmitFields()) { // since 2.3
writer.serializeAsOmittedField(bean, jgen, provider);
}
}
#Override
public void serializeAsField(Object pojo, JsonGenerator jgen, SerializerProvider provider, PropertyWriter writer) throws Exception {
if (isVisible(pojo, writer)) {
this.antecedent.serializeAsField(pojo, jgen, provider, writer);
} else if (!jgen.canOmitFields()) { // since 2.3
writer.serializeAsOmittedField(pojo, jgen, provider);
}
}
#Override
public void serializeAsElement(Object elementValue, JsonGenerator jgen, SerializerProvider provider, PropertyWriter writer) throws Exception {
if (isVisible(elementValue, writer)) {
this.antecedent.serializeAsElement(elementValue, jgen, provider, writer);
}
}
private static boolean isVisible(Object pojo, PropertyWriter writer) {
// Code to determine if the field should be serialized.
}
}
I then add a custom filter provider to each instance of ObjectMapper.
#SuppressWarnings("deprecation")
public class VisibilityFilterProvider extends SimpleFilterProvider {
private static final long serialVersionUID = 1L;
static final String FILTER_ID = "dummy-filter-id";
#Override
public BeanPropertyFilter findFilter(Object filterId) {
return super.findFilter(filterId);
}
#Override
public PropertyFilter findPropertyFilter(Object filterId, Object valueToFilter) {
if (FILTER_ID.equals(filterId)) {
// This implies that the class did not have an explict filter annotation.
return new AuthorizationFilter(null);
}
// The class has an explicit filter annotation so delegate to it.
final PropertyFilter antecedent = super.findPropertyFilter(filterId, valueToFilter);
return new VisibilityPropertyFilter(antecedent);
}
}
Finally, I have a Jackson module that automatically registers the custom annotaion introspector so I don't have to add it to each ObjectMapper instance manually.
public class FieldVisibilityModule extends SimpleModule {
private static final long serialVersionUID = 1L;
public FieldVisibilityModule() {
super(PackageVersion.VERSION);
}
#Override
public void setupModule(Module.SetupContext context) {
super.setupModule(context);
// Append after other introspectors (instead of before) since
// explicit annotations should have precedence
context.appendAnnotationIntrospector(new VisibilityAnnotationIntrospector());
}
}
There are more improvements that can be made and I still have more unit tests to write (e.g., handling arrays and collections) but this is the basic strategy I used.
You can try this approach for the same purpose:
#Entity
#Inheritance(
strategy = InheritanceType.SINGLE_TABLE
)
#DiscriminatorColumn(
discriminatorType = DiscriminatorType.STRING,
length = 2
)
#Table(
name = "project"
)
#JsonTypeInfo(
use = Id.CLASS,
include = As.PROPERTY,
property = "#class"
)
#JsonSubTypes({
#Type(
value = BasicProject.class,
name = "basicProject"
),
#Type(
value = AdvanceProject.class,
name = "advanceProject"
)})
public abstract class Project {
private Long id;
private Long version;
}
#Entity
#DiscriminatorValue("AD")
public class AdvanceProject extends Project {
private String name;
private String description;
}
#Entity
#DiscriminatorValue("BS")
public class BasicProject extends Project {
private String name;
}
I don't think you will make it work. I was trying and these are results of my investigation, maybe it will be helpful.
First of all, as #Faron noticed, the #JsonFilterannotation is applied for the class being annotated not a field.
Secondly, I see things this way. Let's imagine, somewhere in Jackson internals you are able to get the actual field. You can figure out if there is the annotation using Java Reflection API. You can even get the filter name. Then you get to the filter and pass the field value there. But it happens at runtime, how will you get the corresponding JsonSerializer of the field type if you decide to serialize the field? It is impossible because of type erasure.
The only alternative I see is to forget about dynamic logic. Then you can do the following things:
1) extend JacksonAnnotationIntrospector (almost the same as implement AnnotationIntrospector but no useless default code) overriding hasIgnoreMarker method. Take a look at this answer
2) criminal starts here. Kinda weird way taking into account your initial goal but still: extend BeanSerializerModifier and filter out fields there. An example can be found here. This way you can define serializer that actually doesn't serialize anything (again, I understand how strange it is but maybe one will find it helpful)
3) similar to the approach above: define useless serializer based on BeanDescription implementing ContextualSerializer's createContextual method. The example of this magic is here
Thanks to this really good blog, I was able to use #JsonView to filter out specific fields from an entity bean based on some custom logic that is determined at runtime.
Since the #JsonFilter does not apply for the fields within a class, I found this to be a cleaner workaround.
Here is the sample code:
#Data
#AllArgsConstructor
public class TestEntity {
private String a;
#JsonView(CustomViews.SecureAccess.class)
private Date b;
#JsonView(CustomViews.SecureAccess.class)
private Integer c;
private List<String> d;
}
public class CustomViews {
public static interface GeneralAccess {}
public static interface SecureAccess {}
public static class GeneralAccessClass implements GeneralAccess {}
public static class SecureAccessClass implements SecureAccess, GeneralAccess {}
public static Class getWriterView(final boolean hasSecureAccess) {
return hasSecureAccess
? SecureAccessClass.class
: GeneralAccessClass.class;
}
}
#Test
public void test() throws JsonProcessingException {
final boolean hasSecureAccess = false; // Custom logic resolved to a boolean value at runtime.
final TestEntity testEntity = new TestEntity("1", new Date(), 2, ImmutableList.of("3", "4", "5"));
final ObjectMapper objectMapper = new ObjectMapper().enable(MapperFeature.DEFAULT_VIEW_INCLUSION);
final String serializedValue = objectMapper
.writerWithView(CustomViews.getWriterView(hasSecureAccess))
.writeValueAsString(testEntity);
Assert.assertTrue(serializedValue.contains("a"));
Assert.assertFalse(serializedValue.contains("b"));
Assert.assertFalse(serializedValue.contains("c"));
Assert.assertTrue(serializedValue.contains("d"));
}

Spring + MongoDB tag #Query with $group not working

NOTE: Go down in order to see the edited message.
I'm trying to imitate this query:
db.sentiments.aggregate([
{"$group" : {_id:{theme_id:"$theme",sentiment_id:"$sentiment"}, count:{$sum:1}}},
{"$sort":{"_id.theme_id":1}} ])
This is the code that I had generated in order to imitate it:
#RepositoryRestResource(collectionResourceRel = "sentiments", path = "sentiments")
public interface SentimentsRepository extends MongoRepository<Sentiments, String> {
Long countByTheme(#Param("theme") String theme);
#Query(value ="[\n" +
" {\"$group\" : {_id:{theme_id:\"$theme\",sentiment_id:\"$sentiment\"}, count:{$sum:1}}},\n" +
"\t{\"$sort\":{\"_id.theme_id\":1}}\n" +
"]",count = true)
List<Object> comptarSentiments();
}
Well this code is returning me this error:
"exception": "org.springframework.data.mongodb.UncategorizedMongoDbException",
"message": "Can't canonicalize query: BadValue unknown operator: $group; nested exception is com.mongodb.MongoException: Can't canonicalize query: BadValue unknown operator: $group",
Actually I'm a begginer in what refers to the use of Spring so I'm very lost, does any one know what should I do?
Thanks and sorry for my bad english, not my native language.
[EDIT]----------------------------------------
Just as the comment wrote by Shawn Clark It's not possible to do it this way, in order to achieve that you will need to create a customRepository.
What's the difference between Spring Data's MongoTemplate and MongoRepository?
I have been trying to do it this way but something doesn't seem to be correct, here is my new code:
#RepositoryRestResource(collectionResourceRel = "sentiments", path = "sentiments")
public interface SentimentsRepository extends CrudRepository<Sentiments, String>, CustomSentimentsRepository {
//Other methods...
}
public interface CustomSentimentsRepository {
List<CountResult> yourCustomMethod();
class CountResult{
String theme;
String sentiment;
int total;
}
}
public class SentimentsRepositoryImpl implements CustomSentimentsRepository {
private final MongoOperations operations;
#Autowired
public SentimentsRepositoryImpl(MongoOperations operations) {
Assert.notNull(operations, "MongoOperations must not be null!");
this.operations = operations;
}
#Override
public List<CountResult> yourCustomMethod(){
Aggregation agg = Aggregation.newAggregation(
Aggregation.group("theme","sentiment").count().as("total"),
Aggregation.project("theme","sentiment").and("total").previousOperation(),
Aggregation.sort(Sort.Direction.DESC, "theme")
);
//Convert the aggregation result into a List
AggregationResults<CountResult> groupResults
= operations.aggregate(agg,"sentiments", CountResult.class);
//List<CountResult> result = groupResults.getMappedResults();
return groupResults.getMappedResults();
}
}
I'm not even able to debbug this code and I'm always getting a 404.
Based on the information I have found you can't do that complex of a #Query on a MongoRepository method. In this case you would want to create a class and implement your comptarSentiments() method using the mongoTemplate to query the data store with your aggregate function. Then create a controller class that exposes a REST endpoint and have it call the repository.
Once you get to doing complex queries in Mongo you lose the ease of #RepositoryRestResource and have to go back to wiring the REST endpoint to the repository yourself.
Spring Data REST : custom query for MongoDB repository
Implementing custom methods of Spring Data repository and exposing them through REST
I finally managed to solve the problem, seems like it was related with the controller and the type of the atribute "total" from the innerClass CountResult, it needs to be a String (this is very important, otherwise the Aggregation.project will fail). Here goes the final code:
public interface CustomSentimentsRepository {
List<CountResult> myCountGroupByThemeAndSentiment();
class CountResult{
public String theme;
public String sentiment;
public String total;
}
}
public class SentimentsRepositoryImpl implements CustomSentimentsRepository {
private final MongoTemplate mongoTemplate;
#Autowired
public SentimentsRepositoryImpl(MongoTemplate mongoTemplate) {
this.mongoTemplate = mongoTemplate;
}
#Override
public List<CountResult> myCountGroupByThemeAndSentiment(){
Aggregation agg = Aggregation.newAggregation(
Aggregation.group("theme","sentiment").count().as("total"),
Aggregation.project("theme","sentiment").andInclude("total"),
Aggregation.sort(Sort.Direction.ASC,"theme","sentiment")
);
AggregationResults<CountResult> groupResults
= mongoTemplate.aggregate(agg,"sentiments", CountResult.class);
return groupResults.getMappedResults();
}
}
#RepositoryRestResource(collectionResourceRel = "sentiments", path = "sentiments")
public interface SentimentsRepository extends CrudRepository<Sentiments, String>, CustomSentimentsRepository {
//Other methods
}
#RestController
#RequestMapping(value = "sentiments/search")
public class ChartsController {
#Autowired
private SentimentsRepository sentimentsRepository;
#RequestMapping(value = "myCountGroupByThemeAndSentiment", method = RequestMethod.GET)
public ResponseEntity<?> yourCustomMethod() {
List<?> count=sentimentsRepository.myCountGroupByThemeAndSentiment();
return new ResponseEntity(count, HttpStatus.OK);
}
}
You can use #Aggrgation available in spring data mongodb 2.2.X versions:
#Aggregation(pipeline = {"{ '$group': { '_id' : '$lastname', names : { $addToSet : '$?0' } } }", "{ '$sort' : { 'lastname' : -1 } }"}) List<PersonAggregate> groupByLastnameAnd(String property);

Criteria in spring data

I'm working on a web application using angular js, spring mvc and spring jpa data.
I'm wondering if there is something similar to criteria and detachedcriteria(hibernate) to build advanced queries with spring jpa data.
Nothing stops you from still using Criteria
#Repository
public interface FooRepository extends JpaRepository<Foo, Long>, FooRepositoryCustom {
}
interface FooRepositoryCustom {
public List<Foo> findByBar(Bar bar);
}
class FooRepositoryImpl implements FooRepositoryCustom {
#PersistenceContext
protected EntityManager em;
#Transactional(readOnly = true)
public List<Foo> findByBar(Bar bar) {
Criteria crit = em.unwrap(Session.class).createCriteria(Foo.class);
crit.add(Restrictions.eq("name", bar.getName()));
...
crit.setResultTransformer(DetachedCriteria.DISTINCT_ROOT_ENTITY);
List<Foo> foos = crit.list();
return foos;
}
}
Yes, you can use Specifications, which basically uses the Criteria API (obviously, since Spring Data JPA is just a wrapper around JPA).
you can use Query Dsl
, it is less verbose than Specification, here is a blog containing both Specification and QueryDsl.
You can use Criteria with Spring Data, you don't need a Custom Repository, You could use JpaSpecificationExecutor, here an example:
Your repository:
#Repository("yourRepository")
public interface YourRepository extends JpaRepository, JpaSpecificationExecutor
{
}
Your Service
#Override
public List<YourModel> yourDataModel getAllEntitiesByAttr(String attrValue){
List<YourModel> yourDataModel = null;
try {
Specification specification=getAndSpecByAttribute("attribute",attrValue);
List list = userRepository.findAll(specification);
yourDataModel =orikaMapper.mapAsList(list, YourModel.class);
} catch (Exception e) {
throw e;
}
return yourDataModel;
}
private Specification getAndSpecByAttribute(String attribute, String valueAttribute){
return new Specification() {
#Override public Predicate toPredicate(Root root, CriteriaQuery query, CriteriaBuilder cb) {
Path path = root.get(attribute);
return cb.equal(path, valueAttribute);
};
};
}
It is enough.

Spring Data Neo4j: Converter of object to string works, but object to long is not executed

I have a really strange issue with converting from domain objects to those Neo4j can natively store as property value. As a test case I use Joda's DateTime. A object of that type can be converted to a String or Long quite easily.
The conversion from DateTime to String works flawlessly with this code:
public class DateTimeToStringConverter implements Converter<DateTime, String> {
#Override
public String convert(DateTime source) {
return source.toDateTimeISO().toString();
}
}
The property shows up in the node:
Node[1] {
'__type__' = '...',
'entityEditedAt' = '2012-12-28T12:32:50.308+01:00',
'entityCreatedAt' = '2012-12-28T12:32:50.297+01:00',
...
}
However if I like to save the DateTime as Long (useful to sort by time in Cypher), it does not work at all. Here is my converter:
public class DateTimeToLongConverter implements Converter<DateTime, Long> {
#Override
public Long convert(DateTime source) {
return source.toDateTimeISO().getMillis();
}
}
The property is not saved on the node. Thus it is missing completely. No exception is thrown. It seems like the conversion code is not called at all.
The converters are hooked to Spring Data using code based configuration:
#Bean
public ConversionServiceFactoryBean conversionService() {
Set converters = Sets.newHashSet();
// These work!
converters.add(new DateTimeToStringConverter());
converters.add(new StringToDateTimeConverter());
// These don't :-(
//converters.add(new DateTimeToLongConverter());
//converters.add(new LongToDateTimeConverter());
ConversionServiceFactoryBean bean = new ConversionServiceFactoryBean();
bean.setConverters(converters);
return bean;
}
Any clues? I'm quite lost here, as it should work in my opinion...
Edit
I found following text in the Spring Data Neo4j documentation:
All fields convertible to a String using the Spring conversion services will be stored as a string.
Does this mean, that only conversions to string are supported? This seems rather limiting.
Tell SDN that you want to store your joda DateTime property as a long with:
#NodeEntity
public class MyEntity {
...
#GraphProperty(propertyType = Long.class)
private DateTime timestamp;
....
}
Then your registered DateTimeToLongConverter will kick in.

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