I have the below JSON below is the POJO and I need to have both the constructors because if there is no choiceType in json I need to default it to Yes, if choiceType in json exists with null value then it should not default to Yes And my goal is to have a list of choices when the above
Tag: jackson
“org.springframework.data.util.TypeInformation.getActualType()” because “propertyType” is null
A Spring Boot 2.5.1 application is logging this warning: whereas Spring Boot 2.4.4 does not. The POJO is trivial: and the Spring RestController is similarly: To trigger the warning submit a POST: The warning is triggered while “handling” the _links property of the EntityModel<SoPojo> but why…
Jackson cannot parse body of a POST request
I am using Spring Boot to implement two web services, User and Book, and I am implementing the POST methods. When I send a POST request, i include the hard-coded JSON object in the HTTP Body: I am working at the same time on the two services, and while the creation of the “user” object works fine,…
Nested generic types in static method
I was trying to develop a generic method that could convert a JSON to a generic object that would have another instantiable generic object inside so I could use it as a parser in several places in my application. I had thought of the following solution, but it doesn’t work: Is there any way to be able t…
Serialize and Deserialize Java object having vavr list
I have a Java object with vavr list. When I serialize the object objectwriter.writeValueAsString(currentDossier) and print the values then in the JSON output I see, where remarks is a vavr list field inside the object. Now if I try to deserialize the same value into the object objectMapper.readValue(json, Cus…
Adding custom arguments to Jackson deserializer
I have a custom deserializer. But I want to be able to pass additional arguments. For example How can I pass in my custom parameter on the annotation? Answer You cannot add your own parameters to @JsonDeserialize, because you can’t alter Jackson’s implementation of this annotation. However, you ca…
Deserialising JSON array using RestTemplate
I’m trying to convert JSON data to a java class using Rest Template. The JSON data has this format and cannot be changed: The java class to save the data is: To receive the JSON data and deserialize i’m doing: But i’m getting this exception: I’ve done this before and it worked, but the…
ObjectMapper writeValueAsString on ‘null’ vs ‘NullNode.getInstance()’
Consider the following statements: String s1 = new ObjectMapper().writeValueAsString(null); String s2 = new ObjectMapper().writeValueAsString(NullNode.getInstance()); In both the cases, serialized values s1 and s2 would be “null” (in String format). Jackson, by default, serializes null objects wit…
@JsonProperty not working after springboot upgrade
I recently upgraded my application from Spring Boot 1.5.3 to Spring Boot 2.3.5. One of the feature on UI started breaking and I found while debugging that the json response to UI had changed Original response: New response: having underscores (_) in attribute names It seems that the @JsonProperty is not worki…
Why does jackson convert byte array to base64 string on converting to json?
When I have a byte array in a DTO and convert it to json using jackson’s ObjectMapper, it automatically converts the byte array into base64 string. Example below. I expected jackson to convert it to an array of integers like the following: But instead, I found it to be converted to base64 string. After …