What is the preferred method for returning null values in JSON? Is there a different preference for primitives? For example, if my object on the server has an Integer called “myCount” with no value, the most correct JSON for that value would be: {} or { “myCount”: null } or { “myCount”: 0 } Same … Read more
This question already has answers here: Jackson with JSON: Unrecognized field, not marked as ignorable (45 answers) Closed 3 years ago. I’m using Jackson JSON library to convert some JSON objects to POJO classes on an android application. The problem is, the JSON objects might change and have new fields added while the application is … Read more
How can Jackson be configured to ignore a field value during serialization if that field’s value is null. For example: public class SomeClass { // what jackson annotation causes jackson to skip over this value if it is null but will // serialize it otherwise private String someValue; } 20 s 20 To suppress serializing … Read more
I need to convert a certain JSON string to a Java object. I am using Jackson for JSON handling. I have no control over the input JSON (I read from a web service). This is my input JSON: {“wrapper”:[{“id”:”13″,”name”:”Fred”}]} Here is a simplified use case: private void tryReading() { String jsonStr = “{\”wrapper\”\:[{\”id\”:\”13\”,\”name\”:\”Fred\”}]}”; ObjectMapper mapper … Read more
The Jackson data binding documentation indicates that Jackson supports deserialising “Arrays of all supported types” but I can’t figure out the exact syntax for this. For a single object I would do this: //json input { “id” : “junk”, “stuff” : “things” } //Java MyClass instance = objectMapper.readValue(json, MyClass.class); Now for an array I want … Read more
When is the @JsonProperty property used and what is it used for?
Exactly how to do this depends on the version of Jackson that you’re using. This changed around version 1.9, before that, you could do this by adding @JsonIgnore to the getter. Which you’ve tried: Add @JsonIgnore on the getter method only Do this, and also add a specific @JsonProperty annotation for your JSON “password” field name to the setter method for the … Read more
No need to go with GSON for this; Jackson can do either plain Maps/Lists: ObjectMapper mapper = new ObjectMapper(); Map<String,Object> map = mapper.readValue(json, Map.class); or more convenient JSON Tree: JsonNode rootNode = mapper.readTree(json); By the way, there is no reason why you could not actually create Java classes and do it (IMO) more conveniently: public … Read more
Eh… after hours of debugging and thinking – the answer turned out to be the most obvious one – both clients I have been using were closing the connection (probably timeout). It worked in wget and postman while using swagger and advanced rest client caused the exception to be thrown.
I need to convert a certain JSON string to a Java object. I am using Jackson for JSON handling. I have no control over the input JSON (I read from a web service). This is my input JSON: {“wrapper”:[{“id”:”13″,”name”:”Fred”}]} Here is a simplified use case: private void tryReading() { String jsonStr = “{\”wrapper\”\:[{\”id\”:\”13\”,\”name\”:\”Fred\”}]}”; ObjectMapper mapper … Read more
