As a boolean:
{
"fieldOne": "hello world",
"fieldTwo": true,
"foobar": {
"boolean": false
}
}If value is null:
{
"fieldOne": "hello world",
"fieldTwo": true,
"foobar": null
}The above is what a field will look like as output where in Avro that field is defined as one of the Complex Types – Unions. Example below, it declares a schema which may be one of null or boolean.
{
"type": [
"null",
"boolean"
]
}
In Java, there is Jackson 2 library that is very popularly used when reading JSON objects and mapping those values out to a POJO.
Happy path, as long a I have all the fields from the JSON defined in the POJO then okay. In a perfect world it will work 100%.
But there is no perfect world. The JSON object in other scenarios can contain unknown fields. These are not in my POJO. Application fails from reading that JSON to POJO.
Getting this error:
Exception in thread "main" com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "status" (class com.example.dto.Evaluation), not marked as ignorable (6 known properties: "Book",
ANSWER
Use this Jackson annotation at a class level. This has to be configured per class. That should do it. Will ignore any unknown properties silently including nested objects.
@JsonIgnoreProperties(ignoreUnknown = true)When you are using Jackson ObjectMapper directly, that can be configured to ignore unknown properties globally as well.
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);