Please note that I have looked at similar questions and I have explained why they haven't worked for me
I have a simple Spring boot JPA-Hibernate application with one to one mapping between User and Address. (Please note that I do not have this issue with one to many mapping)
User Entity
@Entity
@Table(name = "users")
public class User implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Integer id;
@Column
private String name;
@OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "user")
private Address address;
@OneToMany(fetch = FetchType.LAZY, mappedBy = "user")
private Set<Note> notes;
}
Address Entity
@Entity
@Table(name = "addresses")
public class Address implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Integer id;
@Column
private String street;
@Column
private String city;
@JsonIgnore
@OneToOne
@JoinColumn(name = "user_id")
private User user;
}
Note Entity
@Entity
@Table(name = "notes")
public class Note implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Integer id;
@Column
private String date;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "user_id", nullable = false)
private User user;
}
My problem is that whenever I call the controller mapped to get all users I was getting the address and all the associated notes with it as well. But I would expect FetchType.LAZY
to take care of that.
I read a lot of questions on StackOverflow mentioning that Jackson might be the culprit here:
I also read that spring.jpa.open-in-view defualt value might be the culprit:
So i tried the following options:
I disabled default open in view property by adding spring.jpa.open-in-view=false
to my application.properties
which started giving me
Could not write JSON: failed to lazily initialize a collection of role error
I am assuming its because Jackson is calling the getters on my lazily loaded objects so I followed the instructions from another post and added the following for Jackson to leave the lazily loaded collections alone:
pom.xml
<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-hibernate5</artifactId>
<version>2.9.9</version>
</dependency>
@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {
@Override
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
for (HttpMessageConverter converter : converters) {
if (converter instanceof org.springframework.http.converter.json.MappingJackson2HttpMessageConverter) {
ObjectMapper mapper = ((MappingJackson2HttpMessageConverter) converter).getObjectMapper();
mapper.registerModule(new Hibernate5Module());
}
}
}
}
This solution above fixed the issue with the One to Many mapping but still has the Address associated in the response.
I am not sure what can I do here. The User Entity on the default landing page does not need any address details so I do not want to load it on the landing page. When the record is clicked then it navigates to another page and that's where I would like all the lazy loaded objects to be returned in the response.
I have tried everything I could find online but still nothing has worked so far. I would really appreciate some help with this.
As mentioned by one of the users that it might a duplicate of another question on SO: Suggested Possible duplicate I would like to mention that I got the Lazy loading working by disabling spring.jpa.open-in-view property but adding
mapper.registerModule(new Hibernate5Module());
brings back the address associated to the User in the response.