What is the function of the @JsonIgnore annotation in Jackson?
A) To exclude a field from serialization and deserialization
B) To rename a field in the JSON output
C) To define a default value for a field
D) To include only non-null fields in the JSON output
Answer:
A) To exclude a field from serialization and deserialization
Explanation:
The @JsonIgnore annotation in Jackson is used to exclude a field from both serialization and deserialization. When applied to a field, this annotation ensures that the field is not included in the JSON output when the object is serialized, and it is not populated from the JSON input during deserialization.
For example:
public class SomeClass {
private String name;
@JsonIgnore
private int age;
// other fields
}
In this example, the age field will be ignored by Jackson during both serialization and deserialization, meaning it will not appear in the JSON representation of the object.