org.hibernate.PropertyAccessException: Could not set field value [1] value by reflection - spring

Question

Hi guys I am new to Spring and I am getting this error in my project:
org.hibernate.PropertyAccessException: Could not set field value [1] value by
reflection : [class com.**.domain.identities.NurseAgencyIdentity.agencyId]
setter of com.**.domain.identities.NurseAgencyIdentity.agencyId
There are some classes involved in this process: Nurse , Agency, Named(abstract), NurseAgency and NurseAgencyIdentity. There is a many-to-many relationship between Nurse--Agency with an extra column nurse record. The Named class is an abstract class that contains the fields id and name and is being used by many tables in my design being id the identifier of the descendant table. To implement the many-to-many I had to use the #Embeddable annotation in the last class NurseAgencyIdentity which is the id of my NurseAgency join table. Here is the code:
NurseAgencyIdentity
#Embeddable
#Data
public class NurseAgencyIdentity implements Serializable {
#Column(name="nurse_id")
private Long nurseId;
#Column(name="agency_id")
private Long agencyId;
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
NurseAgencyIdentity that = (NurseAgencyIdentity) o;
return Objects.equals(nurseId, that.nurseId) &&
Objects.equals(agencyId, that.agencyId);
}
#Override
public int hashCode() {
return Objects.hash(nurseId, agencyId);
}
}
NurseAgency
#Entity
#Data
public class NurseAgency {
#EmbeddedId
private NurseAgencyIdentity id;
#ManyToOne(fetch = FetchType.LAZY)
#MapsId("nurseId")
private Nurse nurse;
#ManyToOne(fetch = FetchType.LAZY)
#MapsId("agencyId")
private Agency agency;
private String nurseRecord;
}
Nurse
#Entity
#Data
public class Nurse {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String firstName;
private String lastName;
#Enumerated(EnumType.STRING)
private License license;
#OneToMany(mappedBy = "nurse", cascade = CascadeType.ALL, orphanRemoval = true)
private List<NurseAgency> agencies = new ArrayList<>();
// need the extra column
public void addAgency(Agency agency) {//, String nurseRecord) {
NurseAgency nurseAgency = new NurseAgency();
nurseAgency.setAgency(agency);
nurseAgency.setNurse(this);
//nurseAgency.setNurseRecord(nurseRecord);
agency.getNurses().add(nurseAgency);
}
public void removeAgency(Agency agency) {
for (Iterator<NurseAgency> iterator = agencies.iterator(); iterator.hasNext(); ) {
NurseAgency nurseAgency = iterator.next();
if (nurseAgency.getNurse().equals(this) && nurseAgency.getAgency().equals(agency)){
iterator.remove();
nurseAgency.getAgency().getNurses().remove(nurseAgency);
nurseAgency.setNurse(null);
nurseAgency.setAgency(null);
}
}
}
#Override
public String toString() {
return id + " " + firstName + " " + middleName + " " + lastName;
}
}
Named
#MappedSuperclass
#EntityListeners(AuditingEntityListener.class)
#Data
public abstract class Named implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
}
Agency
#Entity
#Data
public class Agency extends Named {
private String description;
#OneToMany(mappedBy = "agency", cascade = CascadeType.ALL, orphanRemoval = true)
private List<NurseAgency> nurses = new ArrayList<>();
}
And I am having this error when trying to seed the join table:
BootStrapData
#Component
public class BootStrapData implements CommandLineRunner {
#Autowired
private final NurseRepository nurseRepository;
#Autowired
private final AgencyRepository agencyRepository;
private final NurseAgencyRepository nurseAgencyRepository;
public BootStrapData(NurseRepository nurseRepository, AgencyRepository agencyRepository, NurseAgencyRepository nurseAgencyRepository) {
this.nurseRepository = nurseRepository;
this.agencyRepository = agencyRepository;
this.nurseAgencyRepository = nurseAgencyRepository;
}
#Override
public void run(String... args) throws Exception {
System.out.println("Loading agencies ");
ArrayList<Agency> agencies = GetAgencies();
System.out.println("Loading Nurses ");
ArrayList<Nurse> nurses = GetNurses(agencies);
nurses.stream().forEach( n -> nurseRepository.save(n));
agencies.stream().forEach( a -> agencyRepository.save(a));
//Nurses Agencies
ArrayList<NurseAgency> nurseAgencies = new ArrayList<>(1);
nurseAgencies.addAll(SetNurseAndAgencies(nurses.get(0), new Agency[]{agencies.get(0), agencies.get(1), agencies.get(2)}));
nurseAgencies.addAll(SetNurseAndAgencies(nurses.get(1), new Agency[]{agencies.get(0), agencies.get(1)}));
nurseAgencies.addAll(SetNurseAndAgencies(nurses.get(2), new Agency[]{agencies.get(1), agencies.get(2)}));
for (int i=0; i<nurseAgencies.size();i++){
nurseAgencyRepository.save(nurseAgencies.get(i)); // I've got the error in first iteration in this line
}
}
private ArrayList<Agency> GetAgencies() {
ArrayList<Agency> agencies = new ArrayList<>(3);
Agency a1 = new Agency();
a1.setName("Agency 1");
agencies.add(a1);
Agency a2 = new Agency();
a2.setName("Agency 2");
agencies.add(a2);
Agency a3 = new Agency();
a3.setName("Agency 3");
agencies.add(a3);
return agencies;
}
private ArrayList<Nurse> GetNurses(ArrayList<Agency> agencies) {
ArrayList<Nurse> nurses = new ArrayList<>(3);
Nurse n1 = new Nurse();
n1.setFirstName("Mario");
n1.setLastName("Perez");
nurses.add(n1);
Nurse n2 = new Nurse();
n2.setFirstName("Luis");
n2.setLastName("Ruiz");
nurses.add(n2);
Nurse n3 = new Nurse();
n3.setFirstName("Maria");
n3.setLastName("Crez");
nurses.add(n3);
return nurses;
}
private ArrayList<NurseAgency> SetNurseAndAgencies(Nurse nurse, Agency[] agencies) {
ArrayList<NurseAgency> nurseagencies = new ArrayList<>(agencies.length);
for (int i=0; i<agencies.length; i++){
NurseAgency na = new NurseAgency();
na.setNurse(nurse);
na.setAgency(agencies[i]);
na.setNurseRecord(nurse.getFirstName() + agencies[i].getName());
nurseagencies.add(na);
}
return nurseagencies;
}
}
Where is the problem?

Answer 1

Try changing the NurseAgencyIdentity declaration on NurseAgency from:
#EmbeddedId
private NurseAgencyIdentity id;
to:
#EmbeddedId
private NurseAgencyIdentity id = new NurseAgencyIdentity();
I didn't see the full stack trace but the root cause can be a NullPointerException when hibernate tries to set fields (generated agencyId [ 1 ] in your case) via reflection on NurseAgencyIdentity and it's null.
See org.hibernate.tuple.entity.AbstractEntityTuplizer#getIdentifier