How to use beforeInsert() and beforeUpdate() in GORM - grails

Question

I'm working on an inventory management system in Grails, the application will keep track of assets information such as Users, Brand, Type etc. I have 3 domain classes (other class are not important for this discussion) namely, User, Movement and Inventory.
Each assets is owned by a particular User. When the asset is transferred from the current owner to a new owner in the Movement class, the change should be reflected in the User class and Inventory class. These are my classes:
User:
class User {
String userID
String fullName
String position
Department department
String toString(){
fullName
}
static hasMany = [inventories: Inventory, movementsByOldUser: Movement, movementsByNewUser: Movement]
static mappedBy = [movementsByOldUser: 'oldUser', movementsByNewUser: 'newUser']
static constraints = {
userID blank: false, unique: true
fullName blank: false
position()
department()
}
}
Movement:
class Movement {
User oldUser
User newUser
Inventory inventoryID
Date movementDate
User userResponsible
static constraints = {
inventoryID blank: false
oldUser blank: false
newUser blank: false
movementDate()
userResponsible blank: false
}
}
Inventory:
class Inventory {
String inventoryID
String code
String description
String serial_num
Date purchase_date
Date record_date
Type type
Brand brand
User user
static hasMany = [movements: Movement]
String toString(){
"$inventoryID, $type"
}
static constraints = {
inventoryID blank: false, unique: true
code blank: false
description nullable: true, maxSize: 1000
serial_num blank: false
purchase_date()
image nullable: true, maxSize: 1000000
record_date()
remarks nullable: true, maxSize: 1000
type()
brand()
user()
}
}
I have heard of the GORM method called beforeInsert() and beforeUpdate() that they can do the job, but I'm completely new to Grails, Groovy and of course GORM as this is the first application I develop, I have no idea how to use them in my codes. I did host of research but none match my scenario so I cannot get a clear picture of how to use it.
Question edited from here:
I have made some changes to the class User by using beforeUpdate() and beforeUpdate() but it gets an error shown below.
User class (edited version):
class User {
String userID
String fullName
String position
Department department
String toString(){
fullName
}
static hasMany = [inventories: Inventory, movementsByOldUser: Movement, movementsByNewUser: Movement]
static mappedBy = [movementsByOldUser: 'oldUser', movementsByNewUser: 'newUser']
def beforeInsert(){
this.fullName = 'oldUser'
}
def beforeUpdate(){
this.fullName = 'newUser'
}
static constraints = {
userID blank: false, unique: true
fullName blank: false
position()
department()
}
}
Error:
#
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00000000543e4bc2, pid=7488, tid=6520
#
# JRE version: Java(TM) SE Runtime Environment (8.0_05-b13) (build 1.8.0_05-b13)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.5-b02 mixed mode windows-amd64compressed oops)
# Problematic frame:
# V [jvm.dll+0x424bc2]
#
# Failed to write core dump. Minidumps are not enabled by default on client versions of Windows
#
# An error report file with more information is saved as:
# C:\Users\Kanaan\MFEDinventory\hs_err_pid7488.log
#
# Compiler replay data is saved as:
# C:\Users\Kanaan\MFEDinventory\replay_pid7488.log
#
# If you would like to submit a bug report, please visit:
# http://bugreport.sun.com/bugreport/crash.jsp
#
| Error Forked Grails VM exited with error