Grails 3 中一对多域的深拷贝
Deep copy of one-to-many domains in Grails 3
我很困惑如何实现这个或者它是否真的 possible/appropriate。我和我的同事正在使用 Grails 3 为客户构建一个 Web 应用程序。他创建了初始域，我猜这是来自移动应用程序的 Realm 模型的几乎一对一的副本。从那以后，我修改了它们，试图让某种形式的深度克隆工作，因为三个域具有一对多关系。
问题
我将如何创建域的深层副本？我尝试了建议的答案但收效甚微：
Proper Implementation of clone() For Domain Classes to duplicate a Grails domain instance
can GORM duplicate whole object?
Cloning an instance of domain in Grails
从不同的地方挑选想法，我已经制定了如下所示的 clone(Domain) 方法。它 几乎 有效（我认为），但集合抛出 HibernateException - Found shared references to a collection: Location.equipments.
存在问题
在控制器中调用为：
def copy() {
Survey.clone(Survey.get(params.id))
redirect action: 'index'
}
有什么想法或指导吗？
目前域名如下：
class Survey {
int id
String name
String contactName
String contactEmail
String facilityAddress
String facilityCity
String facilityStateProvince
String facilityZip
String distributorName
String distributorEmail
String distributorPhoneNumber
static Survey clone(Survey self) {
Survey clone = new Survey()
String exclude = "locations"
clone.properties = self.properties.findAll {
it.key != exclude
}
self.locations.each {
Location copy = Location.clone it
clone.addToLocations copy
}
clone.save()
}
static transients = ['clone']
static belongsTo = User
static hasMany = [locations: Location]
}
class Location {
int id
String name
String[] hazardsPresent
HazardType[] hazardTypes
ExposureArea[] exposureArea
RiskLevel exposureLevel
String comments
byte[] picture
static Location clone(Location self) {
Location clone = new Location()
String[] excludes = ['equipment', 'products']
clone.properties = self.properties.findAll {
!(it.key in excludes)
}
self.equipments.each {
Equipment copy = Equipment.clone it
self.addToEquipments copy
}
self.products.each {
RecommendedProduct copy = new RecommendedProduct()
copy.properties = it.properties
copy.save()
clone.addToProducts copy
}
clone.save()
}
static transients = ['clone']
static belongsTo = Survey
static hasMany = [equipments: Equipment, products: RecommendedProduct]
static constraints = {
picture(maxSize: 1024 * 1024)
}
}
class Equipment {
int id
EquipmentType type
String name
Brand brand
// Redacted 26 boolean properties
// ...
static Equipment clone(Equipment self) {
Equipment clone = new Equipment()
String exclude = "extras"
clone.properties = self.properties.findAll {
it.key != exclude
}
self.extras.each {
EquipmentQuestionExtra copy = new EquipmentQuestionExtra()
copy.properties = it.properties
copy.save()
clone.addToExtras copy
}
clone.save()
}
static transients = ['clone']
static belongsTo = Location
static hasMany = [extras: EquipmentQuestionExtra]
}
class RecommendedProduct {
int productId
int quantityChosen
String comment
static belongsTo = Location
}
class EquipmentQuestionExtra {
int id
String questionText
String comment
byte[] picture
static belongsTo = Equipment
static constraints = {
picture(maxSize: 1024 * 1024)
}
}
您的克隆方法可能有问题：您克隆 "all" 属性，包括 ID，这对于深度克隆来说是个坏主意。 This thread 说明当一个对象与休眠缓存中的另一个对象具有相同的属性时抛出您的错误，但具有另一个引用。
因此，您只需将对象的 id 属性 设置为 null（或将其从属性副本中排除）以强制休眠检测它是一个新对象目的。如果仍然无法正常工作，请在 save.
之前调用对象的 discard 方法
您正在保存子实体。不要那样做，只保存实体 Survey (root)。其他的会被级联拯救。
另一方面，正如@Joch 所说，在这种情况下使用克隆不是正确的方法。
您应该为您的实体创建一个重复的方法。以下是如何克隆此结构类型的示例。这是一个有 n 个问题的测试，每个问题有 n 个答案，每个 class.
有一个 "duplicate" 方法
class Test {
String name
static hasMany = [
/**
* Each question of the test
*/
questions: Question
]
/**
* Duplicates this test
*/
Test duplicate(){
Test test = new Test(name:this.name)
this.questions.each{ question ->
test.addToQuestions(question.duplicate(test))
}
test
}
}
class Question {
Integer questionOrder
String title
/**
* Each question belong to a Test
*/
static belongsTo = [test:Test]
static hasMany = [
/**
* Each answer of the test
*/
answers: Answer
]
/**
* Duplicates this test to another edition
* @param edition to be duplicated
* @return duplicated question
*/
Question duplicate(Test test){
if(test){
Question question = new Question(title:this.title)
this.answers.each{ answer->
question.addToAnswers(answer.duplicate())
}
test.addToQuestions(question)
question
}
}
}
class Answer {
String title
boolean correct
/**
* Each answer belongs to a question
*/
static belongsTo = [question:Question]
/**
* Duplicates this answer to another question
* @param edition to be duplicated
* @return duplicated question
*/
Answer duplicate(){
Answer answer = new Answer()
answer.properties['title','correct'] = this.properties['title','answerOrder','correct']
answer
}
}
在 Answer.duplicate() 中，您有一个示例，说明如何绑定其他对象的某些属性。
已经快一年了，我已经完成了这个项目并解决了这个问题。
我想到的解决方案是利用 service layer。我为每个域定义了一个服务。任何需要深度复制集合的域，调用它们关联的服务方法。我只发布两个服务的来源，因为其他方法基本相同。
流程是这样的：
- 创建域的新空白实例。
- 通过
duplicate.properties = original.properties. 复制所有 'primitive' 属性，例如 String、Boolean 等
- 由于上面还设置了 collection/has-many 关系，这将导致
HibernateException 关于共享集合。所以将集合设置为null.
- 调用关联服务方法复制collection/has-many。
- 保存并 return 重复的域。
service/SurveyService.groovy
class SurveyService {
/**
* Attempts to perform a deep copy of a given survey
*
* @param survey The survey instance to duplicate
* @return The duplicated survey instance
*/
Survey duplicateSurvey(Survey originalSurvey) {
Survey duplicatedSurvey = new Survey()
duplicatedSurvey.properties = originalSurvey.properties
duplicatedSurvey.locations = null
duplicatedSurvey.uuid = UUIDGenerator.createUniqueId()
duplicatedSurvey.dateModified = DateUtil.getCurrentDate()
duplicatedSurvey.name = "${originalSurvey.name.replace("(copy)", "").trim()} (copy)"
duplicatedSurvey.save()
duplicatedSurvey.locations = duplicateLocations originalSurvey.locations, duplicatedSurvey
duplicatedSurvey.save()
}
/**
* Attempts to perform a deep copy of a survey's location
*
* @param originalLocations The original location set
* @param duplicatedSurvey The duplicated survey that each survey will belong to
* @return The duplicated location set
*/
Set<Location> duplicateLocations(Set<Location> originalLocations, Survey duplicatedSurvey) {
Set<Location> duplicatedLocations = []
for (originalLocation in originalLocations) {
duplicatedLocations << locationService.duplicateLocation(originalLocation, duplicatedSurvey)
}
duplicatedLocations
}
}
service/LocationService.groovy
class LocationService {
/**
* Performs a deep copy of a given location. The duplicated location name is
* the original location name and the duplicated location ID.
*
* @param originalLocation The location to duplicate
* @param survey The survey that the location will belong to
* @return The duplicated location
*/
Location duplicateLocation(Location originalLocation, Survey survey = null) {
Location duplicatedLocation = new Location()
duplicatedLocation.properties = originalLocation.properties
duplicatedLocation.survey = survey ?: duplicatedLocation.survey
duplicatedLocation.uuid = UUIDGenerator.createUniqueId()
duplicatedLocation.dateModified = DateUtil.currentDate
duplicatedLocation.equipments = null
duplicatedLocation.products = null
duplicatedLocation.save()
duplicatedLocation.name = "${originalLocation.name.replace("(copy)", "").trim()} (copy)"
duplicatedLocation.equipments = duplicateEquipment originalLocation.equipments, duplicatedLocation
duplicatedLocation.products = duplicateProducts originalLocation, duplicatedLocation
duplicatedLocation.save()
duplicatedLocation
}
/**
* Performs a deep copy of a given locations equipments.
*
* @param originalEquipments The original locations equipments
* @param duplicatedLocation The duplicated location; needed for belongsTo association
* @return The duplicated equipment set.
*/
Set<Equipment> duplicateEquipment(Set<Equipment> originalEquipments, Location duplicatedLocation) {
Set<Equipment> duplicatedEquipments = []
for (originalEquipment in originalEquipments) {
Equipment duplicatedEquipment = new Equipment()
duplicatedEquipment.properties = originalEquipment.properties
duplicatedEquipment.uuid = UUIDGenerator.createUniqueId()
duplicatedEquipment.dateModified = DateUtil.currentDate
duplicatedEquipment.location = duplicatedLocation
duplicatedEquipment.extras = null
duplicatedEquipment.save()
duplicatedEquipment.name = "${originalEquipment.name.replace("(copy)", "").trim()} (copy)"
duplicatedEquipment.extras = duplicateExtras originalEquipment.extras, duplicatedEquipment
duplicatedEquipments << duplicatedEquipment
}
duplicatedEquipments
}
/**
* Performs a deep copy of a given locations extras.
*
* @param originalExtras The original location extras
* @param duplicatedEquipment The duplicated equipment; needed for belongsTo association
* @return The duplicated extras set.
*/
Set<EquipmentQuestionExtra> duplicateExtras(Set<EquipmentQuestionExtra> originalExtras, Equipment duplicatedEquipment) {
Set<EquipmentQuestionExtra> duplicatedExtras = []
for (originalExtra in originalExtras) {
EquipmentQuestionExtra duplicatedExtra = new EquipmentQuestionExtra()
duplicatedExtra.properties = originalExtra.properties
duplicatedExtra.equipment = duplicatedEquipment
duplicatedExtra.uuid = UUIDGenerator.createUniqueId()
duplicatedExtra.dateModified = DateUtil.currentDate
duplicatedExtra.save()
duplicatedExtras << duplicatedExtra
}
duplicatedExtras
}
/**
* Performs a deep copy of a given locations products.
*
* @param originalLocation The original location
* @param duplicatedLocation The duplicated location
* @return The duplicated product set.
*/
Set<RecommendedProduct> duplicateProducts(Location originalLocation, Location duplicatedLocation) {
Set<RecommendedProduct> originalProducts = originalLocation.products
Set<RecommendedProduct> duplicatedProducts = []
for (originalProduct in originalProducts) {
RecommendedProduct duplicatedProduct = new RecommendedProduct()
duplicatedProduct.properties = originalProduct.properties
duplicatedProduct.location = duplicatedLocation
duplicatedProduct.uuid = UUIDGenerator.createUniqueId()
duplicatedProduct.dateModified = DateUtil.currentDate
duplicatedProduct.save()
duplicatedProducts << duplicatedProduct
}
duplicatedProducts
}
}
我很困惑如何实现这个或者它是否真的 possible/appropriate。我和我的同事正在使用 Grails 3 为客户构建一个 Web 应用程序。他创建了初始域，我猜这是来自移动应用程序的 Realm 模型的几乎一对一的副本。从那以后，我修改了它们，试图让某种形式的深度克隆工作，因为三个域具有一对多关系。
问题
我将如何创建域的深层副本？我尝试了建议的答案但收效甚微：
Proper Implementation of clone() For Domain Classes to duplicate a Grails domain instance
can GORM duplicate whole object?
Cloning an instance of domain in Grails
从不同的地方挑选想法，我已经制定了如下所示的 clone(Domain) 方法。它 几乎 有效（我认为），但集合抛出 HibernateException - Found shared references to a collection: Location.equipments.
在控制器中调用为：
def copy() {
Survey.clone(Survey.get(params.id))
redirect action: 'index'
}
有什么想法或指导吗？
目前域名如下：
class Survey {
int id
String name
String contactName
String contactEmail
String facilityAddress
String facilityCity
String facilityStateProvince
String facilityZip
String distributorName
String distributorEmail
String distributorPhoneNumber
static Survey clone(Survey self) {
Survey clone = new Survey()
String exclude = "locations"
clone.properties = self.properties.findAll {
it.key != exclude
}
self.locations.each {
Location copy = Location.clone it
clone.addToLocations copy
}
clone.save()
}
static transients = ['clone']
static belongsTo = User
static hasMany = [locations: Location]
}
class Location {
int id
String name
String[] hazardsPresent
HazardType[] hazardTypes
ExposureArea[] exposureArea
RiskLevel exposureLevel
String comments
byte[] picture
static Location clone(Location self) {
Location clone = new Location()
String[] excludes = ['equipment', 'products']
clone.properties = self.properties.findAll {
!(it.key in excludes)
}
self.equipments.each {
Equipment copy = Equipment.clone it
self.addToEquipments copy
}
self.products.each {
RecommendedProduct copy = new RecommendedProduct()
copy.properties = it.properties
copy.save()
clone.addToProducts copy
}
clone.save()
}
static transients = ['clone']
static belongsTo = Survey
static hasMany = [equipments: Equipment, products: RecommendedProduct]
static constraints = {
picture(maxSize: 1024 * 1024)
}
}
class Equipment {
int id
EquipmentType type
String name
Brand brand
// Redacted 26 boolean properties
// ...
static Equipment clone(Equipment self) {
Equipment clone = new Equipment()
String exclude = "extras"
clone.properties = self.properties.findAll {
it.key != exclude
}
self.extras.each {
EquipmentQuestionExtra copy = new EquipmentQuestionExtra()
copy.properties = it.properties
copy.save()
clone.addToExtras copy
}
clone.save()
}
static transients = ['clone']
static belongsTo = Location
static hasMany = [extras: EquipmentQuestionExtra]
}
class RecommendedProduct {
int productId
int quantityChosen
String comment
static belongsTo = Location
}
class EquipmentQuestionExtra {
int id
String questionText
String comment
byte[] picture
static belongsTo = Equipment
static constraints = {
picture(maxSize: 1024 * 1024)
}
}
您的克隆方法可能有问题：您克隆 "all" 属性，包括 ID，这对于深度克隆来说是个坏主意。 This thread 说明当一个对象与休眠缓存中的另一个对象具有相同的属性时抛出您的错误，但具有另一个引用。
因此，您只需将对象的 id 属性 设置为 null（或将其从属性副本中排除）以强制休眠检测它是一个新对象目的。如果仍然无法正常工作，请在 save.
您正在保存子实体。不要那样做，只保存实体 Survey (root)。其他的会被级联拯救。
另一方面，正如@Joch 所说，在这种情况下使用克隆不是正确的方法。
您应该为您的实体创建一个重复的方法。以下是如何克隆此结构类型的示例。这是一个有 n 个问题的测试，每个问题有 n 个答案，每个 class.
有一个 "duplicate" 方法class Test {
String name
static hasMany = [
/**
* Each question of the test
*/
questions: Question
]
/**
* Duplicates this test
*/
Test duplicate(){
Test test = new Test(name:this.name)
this.questions.each{ question ->
test.addToQuestions(question.duplicate(test))
}
test
}
}
class Question {
Integer questionOrder
String title
/**
* Each question belong to a Test
*/
static belongsTo = [test:Test]
static hasMany = [
/**
* Each answer of the test
*/
answers: Answer
]
/**
* Duplicates this test to another edition
* @param edition to be duplicated
* @return duplicated question
*/
Question duplicate(Test test){
if(test){
Question question = new Question(title:this.title)
this.answers.each{ answer->
question.addToAnswers(answer.duplicate())
}
test.addToQuestions(question)
question
}
}
}
class Answer {
String title
boolean correct
/**
* Each answer belongs to a question
*/
static belongsTo = [question:Question]
/**
* Duplicates this answer to another question
* @param edition to be duplicated
* @return duplicated question
*/
Answer duplicate(){
Answer answer = new Answer()
answer.properties['title','correct'] = this.properties['title','answerOrder','correct']
answer
}
}
在 Answer.duplicate() 中，您有一个示例，说明如何绑定其他对象的某些属性。
已经快一年了，我已经完成了这个项目并解决了这个问题。
我想到的解决方案是利用 service layer。我为每个域定义了一个服务。任何需要深度复制集合的域，调用它们关联的服务方法。我只发布两个服务的来源，因为其他方法基本相同。
流程是这样的：
- 创建域的新空白实例。
- 通过
duplicate.properties = original.properties. 复制所有 'primitive' 属性，例如 - 由于上面还设置了 collection/has-many 关系，这将导致
HibernateException关于共享集合。所以将集合设置为null. - 调用关联服务方法复制collection/has-many。
- 保存并 return 重复的域。
String、Boolean 等
service/SurveyService.groovy
class SurveyService {
/**
* Attempts to perform a deep copy of a given survey
*
* @param survey The survey instance to duplicate
* @return The duplicated survey instance
*/
Survey duplicateSurvey(Survey originalSurvey) {
Survey duplicatedSurvey = new Survey()
duplicatedSurvey.properties = originalSurvey.properties
duplicatedSurvey.locations = null
duplicatedSurvey.uuid = UUIDGenerator.createUniqueId()
duplicatedSurvey.dateModified = DateUtil.getCurrentDate()
duplicatedSurvey.name = "${originalSurvey.name.replace("(copy)", "").trim()} (copy)"
duplicatedSurvey.save()
duplicatedSurvey.locations = duplicateLocations originalSurvey.locations, duplicatedSurvey
duplicatedSurvey.save()
}
/**
* Attempts to perform a deep copy of a survey's location
*
* @param originalLocations The original location set
* @param duplicatedSurvey The duplicated survey that each survey will belong to
* @return The duplicated location set
*/
Set<Location> duplicateLocations(Set<Location> originalLocations, Survey duplicatedSurvey) {
Set<Location> duplicatedLocations = []
for (originalLocation in originalLocations) {
duplicatedLocations << locationService.duplicateLocation(originalLocation, duplicatedSurvey)
}
duplicatedLocations
}
}
service/LocationService.groovy
class LocationService {
/**
* Performs a deep copy of a given location. The duplicated location name is
* the original location name and the duplicated location ID.
*
* @param originalLocation The location to duplicate
* @param survey The survey that the location will belong to
* @return The duplicated location
*/
Location duplicateLocation(Location originalLocation, Survey survey = null) {
Location duplicatedLocation = new Location()
duplicatedLocation.properties = originalLocation.properties
duplicatedLocation.survey = survey ?: duplicatedLocation.survey
duplicatedLocation.uuid = UUIDGenerator.createUniqueId()
duplicatedLocation.dateModified = DateUtil.currentDate
duplicatedLocation.equipments = null
duplicatedLocation.products = null
duplicatedLocation.save()
duplicatedLocation.name = "${originalLocation.name.replace("(copy)", "").trim()} (copy)"
duplicatedLocation.equipments = duplicateEquipment originalLocation.equipments, duplicatedLocation
duplicatedLocation.products = duplicateProducts originalLocation, duplicatedLocation
duplicatedLocation.save()
duplicatedLocation
}
/**
* Performs a deep copy of a given locations equipments.
*
* @param originalEquipments The original locations equipments
* @param duplicatedLocation The duplicated location; needed for belongsTo association
* @return The duplicated equipment set.
*/
Set<Equipment> duplicateEquipment(Set<Equipment> originalEquipments, Location duplicatedLocation) {
Set<Equipment> duplicatedEquipments = []
for (originalEquipment in originalEquipments) {
Equipment duplicatedEquipment = new Equipment()
duplicatedEquipment.properties = originalEquipment.properties
duplicatedEquipment.uuid = UUIDGenerator.createUniqueId()
duplicatedEquipment.dateModified = DateUtil.currentDate
duplicatedEquipment.location = duplicatedLocation
duplicatedEquipment.extras = null
duplicatedEquipment.save()
duplicatedEquipment.name = "${originalEquipment.name.replace("(copy)", "").trim()} (copy)"
duplicatedEquipment.extras = duplicateExtras originalEquipment.extras, duplicatedEquipment
duplicatedEquipments << duplicatedEquipment
}
duplicatedEquipments
}
/**
* Performs a deep copy of a given locations extras.
*
* @param originalExtras The original location extras
* @param duplicatedEquipment The duplicated equipment; needed for belongsTo association
* @return The duplicated extras set.
*/
Set<EquipmentQuestionExtra> duplicateExtras(Set<EquipmentQuestionExtra> originalExtras, Equipment duplicatedEquipment) {
Set<EquipmentQuestionExtra> duplicatedExtras = []
for (originalExtra in originalExtras) {
EquipmentQuestionExtra duplicatedExtra = new EquipmentQuestionExtra()
duplicatedExtra.properties = originalExtra.properties
duplicatedExtra.equipment = duplicatedEquipment
duplicatedExtra.uuid = UUIDGenerator.createUniqueId()
duplicatedExtra.dateModified = DateUtil.currentDate
duplicatedExtra.save()
duplicatedExtras << duplicatedExtra
}
duplicatedExtras
}
/**
* Performs a deep copy of a given locations products.
*
* @param originalLocation The original location
* @param duplicatedLocation The duplicated location
* @return The duplicated product set.
*/
Set<RecommendedProduct> duplicateProducts(Location originalLocation, Location duplicatedLocation) {
Set<RecommendedProduct> originalProducts = originalLocation.products
Set<RecommendedProduct> duplicatedProducts = []
for (originalProduct in originalProducts) {
RecommendedProduct duplicatedProduct = new RecommendedProduct()
duplicatedProduct.properties = originalProduct.properties
duplicatedProduct.location = duplicatedLocation
duplicatedProduct.uuid = UUIDGenerator.createUniqueId()
duplicatedProduct.dateModified = DateUtil.currentDate
duplicatedProduct.save()
duplicatedProducts << duplicatedProduct
}
duplicatedProducts
}
}