Jackson JsonMappingException: Infinite recursion (StackOverflowError) - json

Question

I have a problem converting the object into its equivalent JSON.
Following is my class structure:
public class Record {
private byte[] header;
private String mti;
private String bitmap;
private int fieldNumber;
private String data;
private String name;
private String recordType;
private List<Record> subRecords;
private Field recordSchema;
private List<PDSRecord> pdsRecords;
}
In my case, a record can have multiple sub-records and then each sub-record can further have multiple sub-records. Therefore, I came up with this schema to store the records.
The problem I'm facing is due to the Circular Reference of List<Record> inside Record class.
Is there anyway Jackson could convert this object? Also, I would need the complete information of all the sub-records.
Thanks in advance

Answer 1

I was able to solve it. For this, I had to generate a unique Id for every object that is created and mark the class with:
#JsonIdentityInfo(
generator = ObjectIdGenerators.PropertyGenerator.class,
property = "id")
So, the complete class looks like this:
#JsonIdentityInfo(
generator = ObjectIdGenerators.PropertyGenerator.class,
property = "id")
#JsonInclude(JsonInclude.Include.NON_NULL)
#Data // Lombok
public class Record {
private String id;
private byte[] header;
private String mti;
private String bitmap;
private int fieldNumber;
private String data;
private String name;
private String recordType;
#ToString.Exclude // Lombok
private List<Record> subRecords;
private Field recordSchema;
private List<PDSRecord> pdsRecords;
public Record()
{
this.id = UUID.randomUUID().toString();
}
}
Hope it helps.

Answer 2

You can try the below code. I hope this solves your problem.
try{
ObjectMapper mapper = new ObjectMapper();
mapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false);
String value = mapper.writeValueAsString(r3);
System.out.println(value);
}catch(IOException a){
a.printStackTrace();
}
Output:{
"header": "UEFOS0FK",
"mti": "Data",
"bitmap": "Name",
"fieldNumber": 5,
"data": "data",
"name": "name",
"recordType": "Data",
"subRecords": [
{
"header": "UEFOS0FK",
"mti": "Data",
"bitmap": "Name",
"fieldNumber": 5,
"data": "data",
"name": "name",
"recordType": "Data",
"subRecords": [
{
"header": "UEFOS0FK",
"mti": "Data",
"bitmap": "Name",
"fieldNumber": 5,
"data": "data",
"name": "name",
"recordType": "Data",
"subRecords": null,
"recordSchema": "Record schema",
"pdsRecords": []
}
],
"recordSchema": "Record schema",
"pdsRecords": []
}
],
"recordSchema": "Record schema",
"pdsRecords": []
}