JAXB on JAX-RS - JPA Entity with relations returns no JSON HTTP 500 no error on logs (Glassfish) -

i trying build rest endpoint using jax-rs return jpa entities in json format. found similar question though after applying similar changes in case still http 500 internal error code , glassfish produces no log or shows no error messages related request.

here code:

entity class:

@xmlrootelement @entity @table(name = "tb_banner_image") public class bannerimage extends baseentity<integer> {            private filereference filereference;     private string type;     private string labeltitle;     private string labeltext;      public bannerimage() {}      @id         @tablegenerator(name="genbannerimage", table="tb_id_generator",             pkcolumnname="id_name", valuecolumnname="id_val",             pkcolumnvalue="tb_banner_image", allocationsize=1)     @generatedvalue(strategy=generationtype.table, generator="genbannerimage")     @column(name = "id_banner_image", unique = true, nullable = false)     public integer getid() {         return super.getid();     }      @override     public void setid(integer id) {         super.setid(id);     }      @column(name="type")     public string gettype() {         return type;     }      public void settype(string type) {         this.type = type;     }      @manytoone(fetch=fetchtype.lazy)     @joincolumn(name="id_file_reference", nullable=false)        public filereference getfilereference() {         return filereference;     }      public void setfilereference(filereference filereference) {         this.filereference = filereference;     }      @column(name="label_title")     public string getlabeltitle() {         return labeltitle;     }      public void setlabeltitle(string labeltitle) {         this.labeltitle = labeltitle;     }      @column(name="label_text")     public string getlabeltext() {         return labeltext;     }      public void setlabeltext(string labeltext) {         this.labeltext = labeltext;     }  } 

and

@xmlrootelement @entity @table(name = "tb_file_reference") public class filereference extends basenamedentity<string> {      private string type;      public filereference() {}      @id         @tablegenerator(name="genfilereference", table="tb_id_generator",             pkcolumnname="id_name", valuecolumnname="id_val",             pkcolumnvalue="tb_file_reference", allocationsize=1)     @generatedvalue(strategy=generationtype.table, generator="genfilereference")     @column(name = "id_file_reference", unique = true, nullable = false)     public string getid() {         return super.getid();     }     @override     public void setid(string id) {               super.setid(id);     }      @column(name = "type")     public string gettype() {         return type;     }      public void settype(string type) {         this.type = type;     }  } 

base generic superclass:

@mappedsuperclass public abstract class basenamedentity<id extends serializable> implements inamedentity<id>, comparable, serializable {      private id id;     private string name;      protected basenamedentity() {}      public string getname() {         return name;     }      public void setname(string name) {         this.name = name;     }      @transient     public id getid() {         return id;     }      public void setid(id id) {         this.id = id;     }      @override     public boolean equals(object obj) {         if (obj != null && obj instanceof basenamedentity) {             basenamedentity base2 = (basenamedentity) obj;             if (this.getid() != null && base2.getid() != null) {                 return this.getid().equals(base2.getid());               }                    }                return false;     }      @override     public int hashcode() {         return super.hashcode();     }      @override     public string tostring() {         return name;     }      @override     public int compareto(object arg0) {              if (this == arg0) {             return 0;         }                    basenamedentity<id> other = (basenamedentity<id>) arg0;                      return getname().compareto(other.getname());     } } 

application jax-rs configuration:

@applicationpath("/rest") public class portalapplication extends application {     @override     public set<class<?>> getclasses() {         final set<class<?>> classes = new hashset<class<?>>();         // register root resource         classes.add(bannerimageservice.class);         return classes;     } } 

service class:

@path("/banner") public class bannerimageservice extends baseservicefacade<bannerimage, integer> {        public bannerimageservice() {         super(bannerimage.class);     }      @override     protected boolean validateentity(bannerimage entity) {         if (entity != null                 && entity.getid() != null                 && entity.getfilereference() != null                 && entity.getfilereference().getname() != null                 && regexutil.getinstance().validatefilename(                         entity.getfilereference().getname())) {             return true;         }          return false;     }      @override     protected string getdefaultquery() {         return null;     }      @override     protected boolean validateid(integer id) {         return regexutil.getinstance().validateintegerid(id);     }      @override     public crud<bannerimage, integer> lookupservice() throws servicelocatorexception {                   return servicelocator.getinstance()                 .getlocalhome(servicesconstants.banner_image_service);           }    } 

and

public abstract class baseservicefacade<t extends ientity<id>, id extends serializable> implements servicefacaderest<t, id> {      protected static final logger log = logger.getlogger("baseservicefacade");     protected crud<t, id> service;     protected class<t> clazz;      public baseservicefacade(class<t> classe) {              clazz = classe;      }      protected abstract boolean validateentity(t entity);     protected abstract boolean validateid(id id);     protected abstract string getdefaultquery();     protected abstract crud<t, id> lookupservice() throws servicelocatorexception;      public crud<t,id> getservice() {         try {             if (service == null) {                 service = lookupservice();             }          }catch (exception ex) {             logexception(ex);         }         return service;     }      public void setservice(crud<t,id> service) {         this.service = service;     }      public class<t> getclazz() {         return clazz;     }      public void serviceexception(serviceexception ex) {         log.log(level.info, ex.getmessage());     }      public void logexception(exception ex) {         log.log(level.info, ex.getmessage());         ex.printstacktrace();     }      @override     @get     @produces({mediatype.application_xml, mediatype.application_json})     @path("/query")     public list<t> query() {         try {             string defaultquery = getdefaultquery();             if (defaultquery != null) {                 return getservice().search(defaultquery);                            } else {                                 return getservice().findall(clazz);              }                     } catch (serviceexception e) {             serviceexception(e);         } catch (exception ex) {             logexception(ex);         }         return null;     }      @override     @get     @consumes(mediatype.application_json)     @produces({mediatype.application_xml, mediatype.application_json})     @path("/get/{id}")     public t get(@pathparam("id") id id) {         try {             if (validateid(id)) {                 return getservice().findbyid(clazz, id);                 }                 } catch (serviceexception e) {         serviceexception(e);     } catch (exception ex) {         logexception(ex);     }         return null;     }      @override     @post     @consumes(mediatype.application_json)     @produces({mediatype.application_xml, mediatype.application_json})     @path("/create")     public t create(t entity) {         try {                        if (validateentity(entity)) {                 getservice().insert(entity);                 return entity;             }          } catch (serviceexception e) {             serviceexception(e);         } catch (exception ex) {             logexception(ex);         }         return null;     }      @override     @put         @produces({mediatype.application_xml, mediatype.application_json})     @path("/update/{id}")     public t update(t entity) {         try {                        if (validateentity(entity)) {                 return getservice().update(entity);             }         } catch (serviceexception e) {             serviceexception(e);         } catch (exception ex) {             logexception(ex);         }         return null;                 }      @override     @delete     @produces({mediatype.application_xml, mediatype.application_json})     @path("/delete/{id}")     public boolean delete(@pathparam("id") id id) {         try {             if (validateid(id)) {                 return getservice().delete(clazz, id);             }          } catch (serviceexception e) {             serviceexception(e);         } catch (exception ex) {             logexception(ex);         }         return false;     }  } 

when hit localhost/app/rest/banner/query

i http 500 internal error code page , glassfish returns empty html : "the server encountered internal error prevented fulfilling request."

when try search log files see no errors, , calls being made through service layers , back:

[2014-03-19t20:39:28.898-0300] [glassfish 4.0] [fine] [] [org.eclipse.persistence.session.file[tid: _threadid=20 _threadname=http-listener-1(1)] [timemillis: 1395272368898] [levelvalue: 500] [[   select id_banner_image, label_text, label_title, type, id_file_reference tb_banner_image]] 

even though logs show no errors , calls being made, ui can't see what's error source, default http 500 internal error page.

after commenting out @manytoone jpa entity relation of filereference class http 200 , json output like:

[ { "@type":"bannerimage", "id":1, "type":"main" }, { "@type":"bannerimage", "id":2, "type":"main" }, ... 

in entity relation @manytoone(fetch=fetchtype.lazy) if switch @manytoone(fetch=fetchtype.eager)

then json response guess issue related filereference instance being null during original request.

[ { "@type":"bannerimage", "id":1, "filereference":{ "id":"2bdbb063d0d0ee2939c89763945d9d9e", "name":"banner1.png", "type":"image/png" }, "type":"main" }, { "@type":"bannerimage", "id":2, "filereference":{ "id":"b33fa2041f2989f58a25dca2a6a35025", "name":"banner2.png", "type":"image/png" }, "type":"main" }, 

but there @type attribute not on model , created alongside can't determine precisely it's coming from, perhaps it's due response type of "query" method being generic type list<t>

the issue happened related entitymapping fetchtype.lazy after refactoring correct json response after including:

on bannerimageservice.java:

@override protected string getdefaultquery() {     return bannerimagedao.get_all_fetch_file_ref; } 

and in bannerimagedao:

public static final string get_all_fetch_file_ref = "select bannerimage join fetch a.filereference"; 

after manually fetching relation json response correct. strange point glassfish didn't log exceptions or related info related http 500 internal error, guess topic.