jackson ignore field during object creation

Question

I have one problem.

let's say i have a model

public class Student{
     private int id;
     private String name;

   //getters and setters
}

Then i need to create 2 objects in different classes using Student model. In first class i need to create object with 2 fields, in second class with just one field.

public class ClassA{
     Student student = new Student();
     student.setId(id);
     student.setName(name);
}

and

public class ClassB{
     Student student = new Student();
     student.setId(id);
}

Then in second class even though i do not use second field, it is still being added as null.

How can I avoid this?

Is this for serialization or deserialization? What do you expect the value of 2nd field (name) in `ClassB`? — Smile, Jun 09 '20 at 06:52

score 1 · Accepted Answer · answered Jun 09 '20 at 06:40

1

You can use Jackson annotation to ignore null values in result JSON.

@JsonInclude(Include.NON_NULL)
public class ClassB{...}

Read more here: https://www.baeldung.com/jackson-ignore-null-fields

answered Jun 09 '20 at 06:40

Uladzislau Kaminski

2,113
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score 1 · Answer 2 · answered Jun 09 '20 at 06:44

1

If you are using the ObjectMapper to read the data you can ignore the unknown values as shown below.

ObjectMapper mapper = new ObjectMapper();
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

answered Jun 09 '20 at 06:44

Rajesh

4,273
1
32
33

jackson ignore field during object creation

2 Answers2