I have recently explored handling JSON data with the org.json library and all went well. Now I started a bigger Maven project, for which I intend to use the Jackson libraries in stead. Sadly, it does not seem to work for me. I wanted to try out the ObjectMapper class, that VScode autocompleted for me, which also automatically adds the
Tag: jackson
When is a @JsonCreator method required for parsing?
When I try to parse the following object: I get the error And I solved this by adding a creator to the User class like this: This works fine. So now I go and parse the following object: and I don’t get an error… why? why it doesn’t require me to use a constructor here? Here’s the class where the
Jackson Different Deserialization vs Serlialization Method
My Spring Boot API uses camelCase, but I need to proxy some requests through my API to a 3rd party API that uses snake_case. Is it possible to configure Jackson to deserialize the 3rd party response from snake_case, then serialize it back to camelCase to my frontend? Step by step example of desired functionality: Example Object: I call my API
How to write common pojo deserializer for json attribute which can be an object and an array both?
Background: I am getting mismatchedInputException, when parsing json. com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize value of type java.util.ArrayList<Data> from Object value (token JsonToken.START_OBJECT) Problem: nodes is a json-array which contains data, which can be either json-object or json-array . I need to represent this correctly in POJO. Things Tried: Map<String, Object>, List, ,@JsonDeserialize(using = NodeDeserializer.class) Below is my nested json document for ref.
Jackson serializing: Get list of processed objects
For a special case, I need to know which “source objects” of the object tree Jackson processed during serialization. I think there is some internal list, because Jackson might reuse already serialized objects if they are referenced multiple times in the object tree. Can I get this list? Or is it possible to build my own list by an event
Convert a List of JSON-objects input into a nested Map
I have a String input in the following format: Input String: [{ “id”:”1″, “name”:”A”, “address”:”St 1″},{ “id”:”2″, “name”:”B”, “address”:”St 2″}, …] And I want to be able to convert this to a Map<String, Map<String, String>> format. So, something like: Required Output Format: {1: {id:1, name:”A”, address: “St 1″} 2: {id:2, name:”B”, address: “St 2”}} I created a class to help
ERROR: org.codehaus.jackson.map.JsonMappingException
I’m using lombok + Java to otimizate the application. The class has the tags @Data , @EqualsAndHashCode(callSuper = false), @NoArgsConstructor, @AllArgsConstructor e @Builder before signature’s class. When I run, It shows the error below: ERROR: org.apache.cxf.jaxrs.JAXRSRuntimeException: org.codehaus.jackson.map.JsonMappingException: No suitable constructor found for type [simple type, class java.time.LocalDateTime]: can not instantiate from JSON object (need to add/enable type information?) at [Source:
Deserialize json string with nested array of objects with dynamic key
Given the JSON string I need to convert it to my POJO named TransactionInfo JSON String POJO Additional Note (From comment) After the deserialization, I want to access different keys in the transactionProperties map. If it’s converted into a List<Map<String,String>> then it becomes complex. FYI, the keys are guaranteed to be unique so in the end, I want one single
How to get Jackson To Throw An Error on Incorrect Casing On Deserialization
I have the following class: and my mapper looks as follows: Today, if someone messes up their json object for example messing up the capitalization on client: it will deserialize client to null. I’d like it to error because the casing is wrong. (And for any key that’s passed in with bad casing). Is there a way to do this
How to write output of JsonGenerator?
I’m attempting to write the output of data generated by JsonGenerator to console using : From the Java docs – https://docs.oracle.com/en/java/javase/12/docs/api/java.base/java/io/StringWriter.html: Shouldn’t the current value written to the Json generator be outputted when I use : Answer Issue is not closing the generator, updated code : prints :