How to tell Jackson to ignore a field during serialization if its value is null?

There are a few ways to tell Jackson to ignore a field during serialization if its value is null. One way is to use the @JsonInclude annotation with the Include.NON_NULL value on the field or class level.

Here's an example of how you can use the @JsonInclude annotation on a field:

class MyClass {
  @JsonInclude(Include.NON_NULL)
  private String field;
  // other fields and methods
}

Here's an example of how you can use the @JsonInclude annotation on a class:

@JsonInclude(Include.NON_NULL)
class MyClass {
  private String field;
  // other fields and methods
}

Another way to ignore null fields during serialization is to configure the ObjectMapper to do so. You can use the ObjectMapper.setSerializationInclusion method to specify the inclusion rules for serialization. For example:

ObjectMapper mapper = new ObjectMapper();
mapper.setSerializationInclusion(Include.NON_NULL);

This will configure the ObjectMapper to ignore all fields with a null value during serialization.