My problem is similar to this one https://discourse.hibernate.org/t/hibernate-throws-org-hibernate-id-identifiergenerationexception-attempted-to-assign-id-from-null-one-to-one-property/1777 but I am getting a different exception after applying the answer from this thread.
My entities:
@Entity
@Table(name = "location")
public class Location {
@Id
private Long id;
@Column(name = "country_code")
private String countryCode;
private Double longitude;
private Double latitude;
@OneToOne(fetch = FetchType.LAZY)
@MapsId
private Distributor distributor;
public Distributor getDistributor() {
return distributor;
}
// here I apply the advice from the linked thread above
public void setDistributor(Distributor distributor) {
this.distributor = distributor;
this.id = distributor.getId();
}
// other getters/setters
}
@Entity
@Table
public class Distributor {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String site;
@OneToOne(
mappedBy = "distributor",
cascade = CascadeType.ALL,
orphanRemoval = true,
fetch = FetchType.LAZY,
optional = false
)
private Location location;
// getters/setters/constructor
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof Distributor )) return false;
Distributor that = (Distributor ) o;
return Objects.equals(id, that.id);
}
@Override
public int hashCode() {
return id != null ? id.hashCode() : 0;
}
}
Controller with corresponding Spring Data Repository:
@PostMapping
public ResponseEntity<Distributor> test(@RequestBody Distributor distributor) {
distributor.getLocation().setDistributor (distributor);
return ResponseEntity.ok(repository.save(distributor));
}
With this payload:
{
"name" : "name1",
"location" : {
"countryCode" : "US",
"longitude" : 34 ,
"latitude" : 12
}
}
I am getting an endless nested response with proper fields(distributor -> location -> distributor -> location ..), which ends with SO Error:
java.lang.StackOverflowError: null
at java.base/java.lang.ClassLoader.defineClass1(Native Method) ~[na:na]
at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1016) ~[na:na]
at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:174) ~[na:na]
at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:800) ~[na:na]
at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:698) ~[na:na]
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:621) ~[na:na]
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:579) ~[na:na]
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) ~[na:na]
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ~[na:na]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:741) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0]
.
I can’t fathom why does this happen, I followed all available tutorials.
Advertisement
Answer
That’s because there is a cyclic dependency between Location
and Distributor
.
As both have reference to each other, they keep serializing inner reference.
You can avoid that using jackson
annotation @JsonBackReference
and @JsonManagedReference
.
JsonBackReference: skips serialization of annotated property
JsonManagedReference : forward reference and serializes annotated property
In your case, this should work.
//Distributor class
@JsonManagedReference
private Location location;
//Location class
@JsonBackReference
private Distributor distributor;