Strange Jackson exception being thrown when serializing Hibernate object

Question

Jackson is throwing a weird exception that I don t know how to fix  I m using Spring  Hibernate and Jackson   I have already considered that lazy-loading is causing the problem  but I have taken measures to tell Jackson to NOT process various properties as follows    JsonIgnoreProperties    sentMessages    receivedMessages    educationFacility     public class Director extends UserAccount implements EducationFacilityUser               I have done the same thing for all the other UserAccount subclasses as well   Here s the exception being thrown   org codehaus jackson map JsonMappingException  No serializer found for class org hibernate proxy pojo javassist JavassistLazyInitializer and no properties discovered to create BeanSerializer  to avoid exception  disable SerializationConfig Feature FAIL ON EMPTY BEANS     through reference chain  java util ArrayList 46 - gt jobprep domain educationfacility Director    javassist 2  handler        at org codehaus jackson map ser StdSerializerProvider 1 serialize StdSerializerProvider java 62      at org codehaus jackson map ser BeanPropertyWriter serializeAsField BeanPropertyWriter java 268      at org codehaus jackson map ser BeanSerializer serializeFields BeanSerializer java 146      at org codehaus jackson map ser BeanSerializer serialize BeanSerializer java 118      at org codehaus jackson map ser ContainerSerializers IndexedListSerializer serializeContents ContainerSerializers java 236      at org codehaus jackson map ser ContainerSerializers IndexedListSerializer serializeContents ContainerSerializers java 189      at org codehaus jackson map ser ContainerSerializers AsArraySerializer serialize ContainerSerializers java 111      at org codehaus jackson map ser StdSerializerProvider  serializeValue StdSerializerProvider java 296      at org codehaus jackson map ser StdSerializerProvider serializeValue StdSerializerProvider java 224      at org codehaus jackson map ObjectMapper writeValue ObjectMapper java 925      at org springframework http converter json MappingJacksonHttpMessageConverter writeInternal MappingJacksonHttpMessageConverter java 153    Suggestions on how I can get more info to see what s causing this  Anyone know how to fix it   EDIT  I discovered that getHander   and other get    methods exist on the proxy object  GRR   Is there any way I can tell Jackson to not process anything on the proxy  or am I sol  This is really weird because the method that spits out the JSON only crashes under certain circumstances  not all the time  Nonetheless  it s due to the get    methods on the proxy object   Aside  Proxies are evil  They disrupt Jackson  equals   and many other parts of regular Java programming  I am tempted to ditch Hibernate altogether

User · Answer

I faced the same issue and It is really strange that the same code works in few case whereas it failed in some random cases.

I got it fixed by just making sure the proper setter/getter (Making sure the case sensitivity)

User · Answer

It s not ideal  but you could disable Jackson s auto-discovery of JSON properties  using  JsonAutoDetect at the class level  This would prevent it from trying to handle the Javassist stuff  and failing    This means that you then have to annotate each getter manually  with  JsonProperty   but that s not necessarily a bad thing  since it keeps things explicit

User · Answer

I had the same problem  See if you are using hibernatesession load    If so  try converting to hibernatesession get    This solved my problem

User · Answer

I had the same error message from spring s  RestController  My rest controller class was using  spring s JpaRepository class and by replacing repository getOne id  method call with repository findOne id  problem was gone

User · Answer

Also you can make your domain object Director final  It is not perfect solution but it prevent creating proxy-subclass of you domain class

User · Answer

Similar to other answers  the problem for me was declaring a many-to-one column to do lazy fetching  Switching to eager fetching fixed the problem  Before    ManyToOne targetEntity   StatusCode class  fetch   FetchType LAZY    After    ManyToOne targetEntity   StatusCode class  fetch   FetchType EAGER

User · Answer

i got the same error  but with no relation to Hibernate  I got scared here from all frightening suggestions  which i guess relevant in case of Hibernate and lazy loading    However  in my case i got the error since in an inner class i had no getters setters  so the BeanSerializer could not serialize the data      Adding getters  amp  setters resolved the problem

User · Answer

I got the same issue  salutations are here  Avoid Jackson serialization on non fetched lazy objects   http   blog pastelstudios com 2012 03 12 spring-3-1-hibernate-4-jackson-module-hibernate   https   github com nessonqk jackson-datatype-hibernate

User · Answer

For what it s worth  there is Jackson Hibernate module project that just started  and which should solve this problem and hopefully others as well  Project is related to Jackson project  although not part of core source  This is mostly to allow simpler release process  it will require Jackson 1 7 as that s when Module API is being introduced

User · Answer

I tried  JsonDetect and   JsonIgnoreProperties value      handler    hibernateLazyInitializer      Neither of them worked for me  Using a third-party module seemed like a lot of work to me  So I just tried making a get call on any property of the lazy object before passing to jackson for serlization  The working code snippet looked something like this     RequestMapping value     authenticate   produces    application json  charset utf-8        ResponseBody      Transactional     public Account authenticate Principal principal            UsernamePasswordAuthenticationToken usernamePasswordAuthenticationToken    UsernamePasswordAuthenticationToken  principal          LoggedInUserDetails loggedInUserDetails    LoggedInUserDetails  usernamePasswordAuthenticationToken getPrincipal            User user   userRepository findOne loggedInUserDetails getUserId             Account account   user getAccount            account getFullName           Since  account is lazy giving it directly to jackson for serlization didn t worked  amp  hence  this quick-fix          return account

User · Answer

I am New to Jackson API  when i got the   org codehaus jackson map JsonMappingException  No serializer found for class com company project yourclass    I added the getter and setter to com company project yourclass  that helped me to use the ObjectMapper s mapper object to write the java object into a flat file

User · Answer

You can add a Jackson mixin on Object class to always ignore hibernate-related properties  If you are using Spring Boot put this in your Application class    Bean public Jackson2ObjectMapperBuilder jacksonBuilder         Jackson2ObjectMapperBuilder b   new Jackson2ObjectMapperBuilder        b mixIn Object class  IgnoreHibernatePropertiesInJackson class       return b       JsonIgnoreProperties   hibernateLazyInitializer    handler    private abstract class IgnoreHibernatePropertiesInJackson

User · Answer

I had a similar problem with lazy loading via the hibernate proxy object  Got around it by annotating the class having lazyloaded private properties with    JsonIgnoreProperties   hibernateLazyInitializer    handler      I assume you can add the properties on your proxy object that breaks the JSON serialization to that annotation   Avoid Jackson serialization on non fetched lazy objects

User · Answer

You can use jackson-datatype-hibernate module to solve this problem  It work for me  reference  https   github com FasterXML jackson-datatype-hibernate

User · Answer

You could use  JsonIgnoreProperties value      handler    hibernateLazyInitializer     annotation on your class  Director

[java] Strange Jackson exception being thrown when serializing Hibernate object

Examples related to java

Examples related to json

Examples related to hibernate

Examples related to spring-mvc

Examples related to jackson