Grails domain constructor with JSON parameter did not work - json

Question

I have such controller in my grails project:
def submit() {
def json = request.JSON
Share share = new Share(json)
share.save(flush: true, failOnError: true)
}
Class Share looks like this:
class Share {
String timestamp
String deviceName
String originMessage
Share(JSONObject originalMessage) {
println "Run JSON constructor"
println "$originalMessage"
originMessage = originalMessage.toString()
timestamp = originalMessage.timestamp
deviceName = originalMessage.device
}
It recives JSON request and try to persist in data base.
I get such error in my console on failOnError:
Field error in object 'com.entity.Share' on field 'deviceName': rejected value [null];
Field error in object 'com.entity.Share' on field 'originMessage': rejected value [null]; codes
A lot of dancing around find one possible way: in controller convert JSON to string and pass it in constructor where parameter would be type String and then parse it back in JSON using JSON converter. But why I can not pass JSON Object as parameter correctly. What happens?

Answer 1

I don't see much point in declaring this constructor because domain classes already have an implicit constructor that takes a Map argument. You could call this constructor with the JSONObject because this class implements Map, e.g.
class Share {
String timestamp
String deviceName
String originMessage
}
def json = request.JSON
Share share = new Share(json)
The reason for these errors
Field error in object 'com.entity.Share' on field 'deviceName': rejected value [null];
Field error in object 'com.entity.Share' on field 'originMessage': rejected value [null]; codes
is that your JSONObject instance does not have non-null properties named deviceName or originMessage.
Either you need to figure out why these properties are missing, or allow these properties to be null by adding the following constraints to the domain class
class Share {
String timestamp
String deviceName
String originMessage
static constraints = {
deviceName nullable: true
originMessage nullable: true
}
}