Question

我想知道如何将克隆功能添加到我的grails应用程序中。我在下面附上了一张图片，说明了我的域类如何关联。一个模板有许多步骤，每个步骤都有许多输入和/或输出。

Temp

目前我可以在index.gsp页面上查看我的模板，但我希望能够克隆整个模板及其包含的步骤/输入/输出。

这是可能的，如果是这样的话怎么样？

Answer 1

这是深度克隆的一个版本。虽然它有点定制以满足特定需求，但它非常通用。而且我很确定上面说的情况很好地涵盖了这个。

 Object deepClone(def domainInstanceToClone, def notCloneable) {
        return deepClone(domainInstanceToClone, notCloneable, null)
    }

Object deepClone(def domainInstanceToClone) {
    return deepClone(domainInstanceToClone, null, null)
}

Object deepClone(def domainInstanceToClone, def notCloneable, def bindOriginal) {

    if (domainInstanceToClone.getClass().name.contains("_javassist"))
        return null

    //Our target instance for the instance we want to clone
    def newDomainInstance = domainInstanceToClone?.getClass()?.newInstance()

    //Returns a DefaultGrailsDomainClass (as interface GrailsDomainClass) for inspecting properties
    GrailsClass domainClass = domainInstanceToClone.domainClass.grailsApplication.getDomainClass(newDomainInstance.getClass().name)

    for (DefaultGrailsDomainClassProperty prop in domainClass?.getPersistentProperties()) {
        if (notCloneable && prop.name in notCloneable) {
            continue
        }
        if (bindOriginal && prop.name in bindOriginal) {
            newDomainInstance."${prop.name}" = domainInstanceToClone."${prop.name}"
            continue
        }

        if (prop.association) {
            if (prop.owningSide) {
                //we have to deep clone owned associations
                if (prop.oneToOne) {
                    def newAssociationInstance = deepClone(domainInstanceToClone?."${prop.name}", notCloneable, bindOriginal)
                    newDomainInstance."${prop.name}" = newAssociationInstance
                } else {
                    domainInstanceToClone."${prop.name}".each { associationInstance ->
                        def newAssociationInstance = deepClone(associationInstance, notCloneable, bindOriginal)

                        if (prop.oneToMany) {
                            if (newAssociationInstance) {
                                newDomainInstance."addTo${prop.name.capitalize()}"(newAssociationInstance)
                            }
                        } else {
                            newDomainInstance."${prop.name}" = newAssociationInstance
                        }
                    }
                }
            } else {
                if (!prop.bidirectional) {
                    //If the association isn't owned or the owner, then we can just do a  shallow copy of the reference.
                    newDomainInstance."${prop.name}" = domainInstanceToClone."${prop.name}"
                }
                // @@JR
                // Yes bidirectional and not owning. E.g. clone Report, belongsTo Organisation which hasMany
                // manyToOne. Just add to the owning objects collection.
                else {
                    //println "${prop.owningSide} - ${prop.name} - ${prop.oneToMany}"
                    //return
                    if (prop.manyToOne) {
                        newDomainInstance."${prop.name}" = domainInstanceToClone."${prop.name}"
                        def owningInstance = domainInstanceToClone."${prop.name}"
                        // Need to find the collection.
                        String otherSide = prop.otherSide.name.capitalize()
                        //println otherSide
                        //owningInstance."addTo${otherSide}"(newDomainInstance)
                    } else if (prop.manyToMany) {
                        //newDomainInstance."${prop.name}" = [] as Set
                        domainInstanceToClone."${prop.name}".each {
                            //newDomainInstance."${prop.name}".add(it)
                        }
                    } else if (prop.oneToMany) {
                        domainInstanceToClone."${prop.name}".each { associationInstance ->
                            def newAssociationInstance = deepClone(associationInstance, notCloneable, bindOriginal)
                            newDomainInstance."addTo${prop.name.capitalize()}"(newAssociationInstance)
                        }
                    }
                }
            }
        } else {
            //If the property isn't an association then simply copy the value
            newDomainInstance."${prop.name}" = domainInstanceToClone."${prop.name}"
            if (prop.name == "activationDate") {
                newDomainInstance."${prop.name}" = new Date()
            }
        }
    }
    return newDomainInstance
}

示例用法是： -

Template cloneTemplate = cloneService.deepClone(originalTemplate,["id","name"],["parent"])

第一个参数是要克隆的原始对象第二个参数是不能克隆的列的列表第三个参数是必须引用的属性列表，因为它是。模板可能属于某个父项，在克隆过程中必须保持相同。

要保存克隆对象，请创建另一个满足自定义要求的方法。以上代码也适用于其他方案。

克隆Grails中的域实例

1 个答案: