Spring boot application with JPA, many to many relation with additional attributes returning infinite recursion error - spring-data-jpa

Question

I tried to return the entity directly as response resulted in error as "Could not write JSON: Infinite recursion (StackOverflowError)", I would like to get the response in both forms with out transforming the data. Can some one suggest work around. Adding the Entity structure for your reference.
Employee Entity
#Entity
#Data
#AllArgsConstructor
#NoArgsConstructor
public class Employee {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long employeeId;
private String firstName;
private String lastName;
private String role;
#OneToMany(mappedBy = "employee")
private Set<EmployeeStream> streams = new HashSet<>();
}
Stream Entity
#Entity
#Data
#AllArgsConstructor
#NoArgsConstructor
public class Stream {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long streamId;
private String streamName;
#OneToMany(mappedBy = "stream")
private Set<EmployeeStream> employees = new HashSet<>();
}
EmployeeStream Entity with additional Attribute experience
#Entity
#Data
#AllArgsConstructor
#NoArgsConstructor
public class EmployeeStream {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#ManyToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "EMPLPOYEE_ID")
private Employee employee;
#ManyToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "STREAM_ID")
private Stream stream;
private double experience;
}
I would like to retrieve data in both forms
{
"employeeId": 1,
"firstName": "George",
"lastName": "Stephen",
"role": "developer",
"streams": [
{
"id": 1,
"stream": {
"streamId": 1,
"streamName": "Java"
},
"experience": 1.2
},
{
"id": 2,
"stream": {
"streamId": 2,
"streamName": "Node JS"
},
"experience": 2
}
]
}
{
"stream": {
"streamId": 1,
"streamName": "Java",
"employees": [
{
"id": 1,
"employee": {
"employeeId": 1,
"firstName": "George",
"lastName": "Stephen",
"role": "developer"
},
"experience": 2
},
{
"id": 2,
"employee": {
"employeeId": 1,
"firstName": "Davis",
"lastName": "Tom",
"role": "developer"
},
"experience": 0.5
}
]
}
}

Answer 1

You need to use #JsonBackReference and #JsonManagedReference as used in the below in below code.
Employee entity
#Entity
#Data
#AllArgsConstructor
#NoArgsConstructor
public class Employee {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long employeeId;
private String firstName;
private String lastName;
private String role;
#OneToMany(mappedBy = "employee")
#JsonManagedReference
private Set<EmployeeStream> streams = new HashSet<>();
}
Stream entity
#Entity
#Data
#AllArgsConstructor
#NoArgsConstructor
public class Stream {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long streamId;
private String streamName;
#OneToMany(mappedBy = "stream")
#JsonManagedReference
private Set<EmployeeStream> employees = new HashSet<>();
}
EmployeeStream entity
#Entity
#Data
#AllArgsConstructor
#NoArgsConstructor
public class EmployeeStream {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#ManyToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "EMPLPOYEE_ID")
#JsonBackReference
private Employee employee;
#ManyToOne(cascade = CascadeType.ALL)
#JoinColumn(name = "STREAM_ID")
#JsonBackReference
private Stream stream;
private double experience;
}
You can find more details here and here
Update: Previously #JsonBackReference and #JsonManagedReference was misplaced, corrected the same.
Note: If still faced any problem then try removing #JsonManagedReference from Stream and Employee entities.