How do you configure Jackson to only include non-null fields in the JSON output?
A) By using the @JsonInclude annotation
B) By using the @JsonIgnore annotation
C) By setting a flag in the JSON
D) By overriding the equals() method
Answer:
A) By using the @JsonInclude annotation
Explanation:
In Jackson, you can configure serialization to include only non-null fields in the JSON output by using the @JsonInclude
annotation. This annotation allows you to specify that only properties with non-null values should be included in the JSON representation.
For example:
public class SomeClass {
@JsonInclude(JsonInclude.Include.NON_NULL)
private String name;
private int age;
// other fields
}
In this example, the name
field will only be included in the JSON output if it is non-null. If the name
is null, it will be omitted from the JSON.