Up here is my Controller code. Up here is my User class code. When I POST the JSON above, I get the age property to be null. I want Jackson to deserialize the empty fields (“” or null) in JSON with default values. Like this: What should I do? Answer You can define a custom getter property where se…
Tag: jackson
Lombok builder pattern with jackson JsonProperty
I have constructed a Java Object using lombok with builder pattern. But, I am getting the following exception when trying to deserialize a Java object using Jackson. This occurs for fields which has @JsonProperty annotation. Exception in thread “main” com.fasterxml.jackson.databind.exc.Unrecognize…
Dynamic serialization using Jackson – removing fields with specific annotations
Went down a path of creating an annotation that would dynamic determine whether a field should be serialized or not. The annotation’s implementation is as follows: Now the code for the Serializer: A little bit of code to show how it works: And the output is as follows: How do I get the field pin to be r…
Jackson polymorphic serialization generates an incorrect class name
When I use Jackson polymorphic serialization, it generates a JSON object with an incorrect fully qualified class name. The code below serializes an XMLGregorianCalendar. The output is: I expected the following: Why does it output java.util.GregorianCalendar? Or more importantly: How do I fix this? Code exampl…
Custom Jackson Deserialization of a Generic Abstract class
I am having issues when trying to deserializing the following class: My generic abstract class: I have two concrete classes which implement MetricValueDto: IntMetricValueDto: FloatMetricValueDto: Any idea of what’s the correct strategy to deserialize MetricValueDto so I can parse it through ObjectMapper…
Jackson error “Illegal character… only regular white space allowed” when parsing JSON
I am trying to retrieve JSON data from a URL but get the following error: My code: The url constructed is i.e https://www.example.org/api/search.json?keywords=iphone&count=50 What is going wrong here? And how can I parse this data successfully? Imports: example response Answer The message should be pretty…
Jackson adds backslash in json
I’m building REST service on Jersey and using Jackson to produce JSON from java classes of my model. Model with absolutely simple values, I think this is the most typical case. But I get strange result: My expecting result: My source values of fields does NOT contains any special characters. These are s…
Java: FasterXML / jackson deserialize array without keys
Is there a way how to deserialize JSON array into following Java class using FasterXML jackson-databind? I only found answers where there are key: value items in the array. Answer Firstly {[“a”, “b”, 1]} is not a Valid Json Array (or JSON) …. JSON Array would look like this [R…
Jackson is ignoring spring.jackson.properties in my spring boot application
Jackson is ignoring spring.jackson.property-naming-strategy=SNAKE_CASE. I am using springBootVersion 1.4.2.RELEASE. In my application.properties file, I have added spring.jackson.property-naming-strategy=SNAKE_CASE But Jackson is not honoring this property, and my REST response is still camelCase. Interesting…
Jackson , java.time , ISO 8601 , serialize without milliseconds
I’m using Jackson 2.8 and need to communicate with an API that doesn’t allow milliseconds within ISO 8601 timestamps. The expected format is this: “2016-12-24T00:00:00Z” I’m using Jackson’s JavaTimeModule with WRITE_DATES_AS_TIMESTAMPS set to false. But this will print mill…