Question 110092 in Json Question posted in
Our archive of expertly curated questions and answers provides insights and solutions to common problems related to this popular data interchange format. From parsing and manipulating JSON data to integrating it with various programming languages and web services, our archive has got you covered. Start exploring today and take your JSON skills to the next level

Json – ObjectMapper returns null value on date field

My data is as below and saved in test folder with name risk.json

[{
    "Risk": "BN",
    "Classification": null,
    "LastDefaultDate": "1915-04-14 00:00:00"
  }]

I have RiskClass defined as below

@Data
@JsonIgnoreProperties({"document"})
public class RiskClass implements KeyedObject {

    String risk;
    String classification;
    Date lastDefaultDate;

    @Override
    public String getKey() {
        return risk;
    }
}

In my data prepare class i am trying to populate one of the map by doing below

List<RiskClass> rList = ObjectUtils.jsonStringToObjList(readFileAsString("test", "risk.json"), RiskClass.class);
Map<String, RiskClass> riskMapLocal = new HashMap<>();
for (RiskClass rMap : rList) {
    riskMapLocal.put(rMap.getRisk(), rMap);
}

now when i try to print riskMapLocal, under lastDefaultDate i get null value.

Tags:

2

Answers


  1. 0

    Property names in json start with uppercase – Risk, etc. Fields in POJO start with lowercase – risk, so they can’t be matched automatically. You can either:

    1. Change them in json to be lowercase
    2. Use annotation JsonProperty on the fields to specify the name of the property to match for this field.
    public class RiskClass {

  @JsonProperty("Risk")
  String risk;
}
    Login or Signup to reply.
  2. 0

    Add an annotation over your property lastDefaultDate:

        @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss")
    LocalDateTime lastDefaultDate;

    Also change type Date to LocalDateTime as Date type is outdated (pun intended). For more details look at this question and its best answer: Spring Data JPA – ZonedDateTime format for json serialization

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search