Spring boot 2.1.0 security change with kotlin data class? - spring-boot

Question

This problem make me physically ill.
Joke aside, I've been trying to add an authentication layer to my web app using spring-boot with security plugin. Here is my data class.
#Document(collection = "user")
data class User (
var name : String,
var password : String,
var email : String,
var type : String,
var status : String,
var balance : Int
){
#Id val id : String = ObjectId.get().toHexString()
}
After some searching, Ctr+C, Ctr+V, I'm successfully set-up some custom authentication that will get user information from database, look like this:
override fun loadUserByUsername(name : String): UserDetails {
logger.info(name)
val user = repo.findByName(name)
return User(user!!.name,passwordEncoder.encode(user.password),AuthorityUtils.NO_AUTHORITIES)
}
Here where the fun begin, its seem that the code never run pass val user = repo.findByName(name). Worst thing is, there are no exception being thrown, the code run to that line and the rest just disappear.
Out of frustration, I decide to fake the return object so that I can get pass the authentication like this:
override fun loadUserByUsername(name : String): UserDetails {
logger.info(name)
//val user = repo.findByName(name)
logger.debug("asdkfhasdklfjhasdf")
return User("string",passwordEncoder.encode("you"),AuthorityUtils.NO_AUTHORITIES)
}
Now, finally I can get some exception:
{
"timestamp": "2018-11-08T18:08:29.541+0000",
"status": 500,
"error": "Internal Server Error",
"message": "No accessor to set property #org.springframework.data.annotation.Id()private final java.lang.String com.sonnbh.jwt.User.id!",
"path": "/user"
}
The exception state that spring cannot access property id so I change the type of id from val to var.
#Document(collection = "user")
data class User (
var name : String,
var password : String,
var email : String,
var type : String,
var status : String,
var balance : Int
){
#Id var id : String = ObjectId.get().toHexString()
}
Finally, my app work as expected. However, after some attempt trying to dig deeper to the problem, I found that this problem only occur to spring-boot v2.1.0. My old project which use spring-boot v2.0.5 actually run fine with val id. This led me to some question:
Did I my old implement of data class User properly? I just want to prevent any change to User.id after its being read from database or init. What can I do to improve?
Why spring-boot v2.1 can't access to the property like spring-boot v2.0.5 did?

Answer 1

Spring Data in 2.1. has changed the way in which it deals with final fields in entities. It no longer uses reflection to override the immutability of the fields, which in general is good. There are a few ways to cope with the problem.
They are described here: https://jira.spring.io/browse/DATACMNS-1374?focusedCommentId=182289&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-182289
Here's what the Spring guys recommend:
Add a #PersistenceConstructor to construct the entity that sets immutable fields.
Add wither methods (MyEntity withXxx(…)) to create a new instance that contains the changed property value.
Alternatively: Use Kotlin's data class feature. This will basically do the same as wither methods.

Answer 2

Can only answer the first part; you could try moving the declaration of ID to be apart of the constructor? That will satisfy your requirement of only initialising when the object is created and it will still be read only.