Adding a dynamic json property as java pojo for jackson

by

You can use JsonAnyGetter annotation which allows to create dynamic key-value pairs. Below example shows how we can generate 3 different keys for the same Label class:

import com.fasterxml.jackson.annotation.JsonAnyGetter;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonRootName;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;

public class JsonApp {

    public static void main(String[] args) throws Exception {
        AddLabel label = new AddLabel("A label");
        label.getLabels().add(AddLabel.Label.remove("Remove"));
        label.getLabels().add(AddLabel.Label.set("Set"));

        ObjectMapper mapper = new ObjectMapper();
        mapper.enable(SerializationFeature.INDENT_OUTPUT);

        System.out.println(mapper.writeValueAsString(label));
    }
}

@JsonRootName(value = "update")
class AddLabel {

    @JsonProperty("labels")
    private List<Label> labels;

    public AddLabel(String labelName) {
        this.labels = new ArrayList<>();
        this.labels.add(Label.add(labelName));
    }

    public List<Label> getLabels() {
        return labels;
    }

    public static class Label {

        private final String key;
        private final String value;

        private Label(String key, String value) {
            this.key = key;
            this.value = value;
        }

        public static Label add(String value) {
            return new Label("add", value);
        }

        public static Label remove(String value) {
            return new Label("remove", value);
        }

        public static Label set(String value) {
            return new Label("set", value);
        }

        @JsonAnyGetter
        public Map<String, String> getDynamic() {
            return Collections.singletonMap(key, value);
        }
    }
}

Above code prints:

{
  "labels" : [ {
    "add" : "A label"
  }, {
    "remove" : "Remove"
  }, {
    "set" : "Set"
  } ]
}

See also:

More Related Contents:

  1. How do I use a custom Serializer with Jackson?
  2. When is the @JsonProperty property used and what is it used for?
  3. Jackson – Deserialize using generic class
  4. How to convert a JSON string to a Map with Jackson JSON
  5. Different names of JSON property during serialization and deserialization
  6. Date format Mapping to JSON Jackson
  7. Deserialize JSON with Jackson into Polymorphic Types – A Complete Example is giving me a compile error
  8. Jackson enum Serializing and DeSerializer
  9. Jackson renames primitive boolean field by removing ‘is’
  10. Jackson JSON Deserialization with Root Element
  11. Jackson ObjectMapper – specify serialization order of object properties
  12. Generics with Spring RESTTemplate
  13. Jackson + Builder Pattern?
  14. How to create a custom deserializer in Jackson for a generic type?
  15. How to convert XML to JSON using only Jackson?
  16. Can we make object as key in map when using JSON?
  17. How to enforce ACCEPT_SINGLE_VALUE_AS_ARRAY in jackson’s deserialization process using annotation
  18. spring mvc not returning json content – error 406
  19. Problem with deserialization of LocalDateTime in Junit test
  20. Jackson conditional @JsonUnwrapped
  21. Jackson – Required property?
  22. How do I disable fail_on_empty_beans in Jackson?
  23. Jsonpath with Jackson or Gson
  24. Deserializing non-string map keys with Jackson
  25. Jackson ObjectMapper DeserializationConfig.Feature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT
  26. JSON Jackson parse different keys into same field
  27. Jackson date-format for OffsetDateTime in Spring Boot
  28. Jackson JSON Deserialization: array elements in each line
  29. Autowiring in JsonDeserializer: SpringBeanAutowiringSupport vs HandlerInstantiator
  30. How to prevent null values inside a Map and null fields inside a bean from getting serialized through Jackson

Leave a Comment