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I've seen some post about this, but it seems that I keep running into the same problem.
Here is a similar post:
JsonMappingException: could not initialize proxy - no Session

The Problem

So the suggestion is to add the following: 

private MappingJackson2HttpMessageConverter jacksonMessageConverter() {
    MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();

    ObjectMapper mapper = new ObjectMapper();
    //Registering Hibernate4Module to support lazy objects
    mapper.registerModule(new Hibernate5Module());

    messageConverter.setObjectMapper(mapper);
    return messageConverter;

}

@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    converters.add(jacksonMessageConverter());
    super.configureMessageConverters(converters);
}

But I don't have a super.configureMessageConverters() method inside super. They say that the easy solution is to add EAGER, but it's not preferred. another solution would be to use @JsonIgnore, but I want to retrieve the corresponding entities. It is said that adding the code that you see above this text is 1 of the proper and clean ways to handle this. Is this still true? If so, then how should I write the super.configureMessageConverters(converters);, cause that seems to be the problem.

Extra info

This problem occurred when I was adding an many to many relationship:

Type

// region: relationships
@ManyToMany(mappedBy = "types")
private Set<License> licenses;
// endregion: relationships

License

@ManyToMany
@JoinTable(name = "license_restrictions",
        joinColumns = @JoinColumn(name = "license_id"),
        inverseJoinColumns = @JoinColumn(name = "type_id"))
private Set<Type> types;
// endregion: relationships

EDITED V1

I've added the following as suggested in the comments: 

@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    converters.add(jackson2HttpMessageConverter());
}

@Bean
public MappingJackson2HttpMessageConverter jackson2HttpMessageConverter() {
    MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
    converter.setObjectMapper(this.jacksonBuilder().build());

    return converter;
}

private Jackson2ObjectMapperBuilder jacksonBuilder() {
    Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();

    Hibernate5Module hibernateModule = new Hibernate5Module();

    hibernateModule.configure(Hibernate5Module.Feature.FORCE_LAZY_LOADING, false);

    builder.modules(hibernateModule);

    // Spring MVC default Objectmapper configuration
    builder.featuresToDisable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
    builder.featuresToDisable(MapperFeature.DEFAULT_VIEW_INCLUSION);

    return builder;
}

This also does not return the result.

result

Types is null while it should be a collection of 2 types.

relationship table

Here you can see that I do have types that are bound to license 1.

Oguzcan
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  • take a look at https://stackoverflow.com/questions/46190099/spring-rest-lazy-loading-with-hibernate – Ali Akbarpour Mar 07 '18 at 04:03
  • @Generic I've looked at the questions/ answer, but it seems that it didn't work for me. I've added my results under the EDITED V1 section. – Oguzcan Mar 07 '18 at 11:38
  • have you tried with @LazyCollection(LazyCollectionOption.FALSE) beside @ManyToMany? – Ali Akbarpour Mar 07 '18 at 11:56
  • @Generic `SyntaxError: JSON.parse: unexpected end of data at line 1 column 63970 of the JSON data` I tried to add that just now, but it loaded way t much data (infinite loop). – Oguzcan Mar 07 '18 at 12:14

0 Answers0