enum fasterxml jackson Serializing and DeSerializer

enum 을 json으로 변환할 때 커스터마이징 하는 방법입니다.

Source

import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.Map;
 
import com.fasterxml.jackson.annotation.JsonValue;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
 
public class Test {
  public enum Number {
    _1, _2, _3;
 
    @JsonValue
    public Integer toValue() {
      return Integer.parseInt(this.name().replace("_", ""));
    }
  }
 
  public static void main(String[] args) throws IOException {
    ObjectMapper mapper = new ObjectMapper();
    Map<Number, String> map = new LinkedHashMap<>();
    map.put(Number._1, "one");
    map.put(Number._2, "two");
    String writeValueAsString = mapper.writer().writeValueAsString(map);
    System.out.println(writeValueAsString);
 
    Map<Number, String> map2 = mapper.readValue(writeValueAsString, new TypeReference<Map<Number, String>>() {
    });
    System.out.println(map2.get(Number._1));
    System.out.println(map2.get(Number._2));
  }
}

Result

{"1":"one","2":"two"}
one
two

Result Without @JsonValue

{"_1":"one","_2":"two"}
one
two