第六章 Caché 设计模式 原型模式
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第六章 Caché 设计模式 原型模式
定义
用原型实例指定创建对象的种类，并且通过拷贝这些原型创建新的对象。
原型模式其实就是从一个对象再创建另外一个可定制的对象，而且不需要知道任何创建的细节。
使用场景
使用原形模式可以解决复杂对象构建资源消耗的问题。也可以用来只读保护。注意其java里继承Cloneable接口。C#继承ICloneable接口。Caché 直接使用%ConstructClone()方法，克隆时不会走构造函数。
优点
一般在初始化的信息不发生变的情况下，克隆是最好的办法，这即隐藏了对象创建的细节，又对性能是大大的提高。
不用重新初始化对象，而是动态地获得对象运行时的状态。
结构图
描述
要求有一个简历类，必须要有姓名，可以设置性别和年龄，可以设置工作经历。最终需要三分简历。
示例
简历类
Class PHA.YX.Design.Prototype.Resume Extends %RegisteredObject
{
Property name As %String [ Private ];
Property sex As %String [ Private ];
Property age As %String [ Private ];
Property timeArea As %String [ Private ];
Property company As %String [ Private ];
Method %OnNew(name As %String) As %Status [ Private, ServerOnly = 1 ]
{
s $this.name = name
Quit $$$OK
}
Method SetPersonalInfo(sex As %String, age As %String)
{
s $this.sex=sex
s $this.age=age
}
Method SetWorkExperience(timeArea As %String, company As %String)
{
s $this.timeArea=timeArea
s $this.company=company
}
Method Display()
{
w ..name _ " " _ ..sex _ " " _ ..age,!
w "工作经历：" _ ..timeArea _ " " _ ..company,!
}
}
初级写法
/// d ##class(PHA.YX.Design.Program).PrototypeExamplePrimary()
ClassMethod PrototypeExamplePrimary()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
s mResumeB = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeB.SetPersonalInfo("男","30")
d mResumeB.SetWorkExperience("2015-2020","XX公司")
s mResumeC = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeC.SetPersonalInfo("男","30")
d mResumeC.SetWorkExperience("2015-2020","XX公司")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
DHC-APP>d ##class(PHA.YX.Design.Program).PrototypeExamplePrimary()
姚鑫 男 30
工作经历：2015-2020 XX公司
姚鑫 男 30
工作经历：2015-2020 XX公司
姚鑫 男 30
工作经历：2015-2020 XX公司
缺点
三分简历需要实例化三次，如果需要一百份，就需要实例化一百次，徒增内存。
中级写法
/// d ##class(PHA.YX.Design.Program).PrototypeExampleIntermediate()
ClassMethod PrototypeExampleIntermediate()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
# dim mResumeB as PHA.YX.Design.Prototype.Resume
s mResumeB = mResumeA
# dim mResumeC as PHA.YX.Design.Prototype.Resume
s mResumeC = mResumeA
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
DHC-APP>d ##class(PHA.YX.Design.Program).PrototypeExampleIntermediate()
姚鑫 男 30
工作经历：2015-2020 XX公司
姚鑫 男 30
工作经历：2015-2020 XX公司
姚鑫 男 30
工作经历：2015-2020 XX公司
缺点
引用传值，改动其中一处其他复制实例一起改动。把mResumeB设置一下年龄，mResumeC设置一下公司。如下：
/// d ##class(PHA.YX.Design.Program).PrototypeExampleIntermediate()
ClassMethod PrototypeExampleIntermediate()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
# dim mResumeB as PHA.YX.Design.Prototype.Resume
s mResumeB = mResumeA
d mResumeB.SetPersonalInfo("男","31")
# dim mResumeC as PHA.YX.Design.Prototype.Resume
s mResumeC = mResumeA
d mResumeC.SetWorkExperience("2017-2020","SS公司")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
运行结果
DHC-APP>d ##class(PHA.YX.Design.Program).PrototypeExampleIntermediate()
姚鑫 男 31
工作经历：2017-2020 SS公司
姚鑫 男 31
工作经历：2017-2020 SS公司
姚鑫 男 31
工作经历：2017-2020 SS公司
高级写法 (浅复制)
使用 .%ConstructClone()方法复制
/// d ##class(PHA.YX.Design.Program).PrototypeExampleSenior()
ClassMethod PrototypeExampleSenior()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
# dim mResumeB as PHA.YX.Design.Prototype.Resume
s mResumeB = mResumeA.%ConstructClone()
d mResumeB.SetPersonalInfo("男","31")
# dim mResumeC as PHA.YX.Design.Prototype.Resume
s mResumeC =mResumeA.%ConstructClone()
d mResumeC.SetWorkExperience("2017-2020","SS公司")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
DHC-APP> d ##class(PHA.YX.Design.Program).PrototypeExampleSenior()
姚鑫 男 30
工作经历：2015-2020 XX公司
姚鑫 男 31
工作经历：2015-2020 XX公司
姚鑫 男 30
工作经历：2017-2020 SS公司
浅复制
如果字段是值类型的，则对该字段执行逐位复制，如果字段是引用类型，则复制引用但不复制引用的对象，因此原始对象及其副本引用统一对象。如下增加一个工作经验类的引用字段：
增加一个WorkExperience类
Class PHA.YX.Design.Prototype.WorkExperience Extends %RegisteredObject
{
Property workDate As %String [ Private ];
Method workDateGet() As %String [ ServerOnly = 1 ]
{
Quit i%workDate
}
Method workDateSet(Arg As %String) As %Status [ ServerOnly = 1 ]
{
s i%workDate = Arg
Quit $$$OK
}
Property company As %String [ Private ];
Method companyGet() As %String [ ServerOnly = 1 ]
{
Quit i%company
}
Method companySet(Arg As %String) As %Status [ ServerOnly = 1 ]
{
s i%company = Arg
Quit $$$OK
}
}
PHA.YX.Design.Prototype.Resume 增加一个work字段引用WorkExperience
Property work As WorkExperience [ Private ];
并且在构造方法初始化它
Method %OnNew(name As %String) As %Status [ Private, ServerOnly = 1 ]
{
s $this.name = name
s ..work = ##class(WorkExperience).%New()
Quit $$$OK
}
给对象添加WorkExperience数据方法
Method CloneWorkExperience()
{
s ..work = ..work.%ConstructClone()
}
输出也修改一下
Method Display()
{
w ..name _ " " _ ..sex _ " " _ ..age,!
w "工作经历：" _ ..timeArea _ " " _ ..company,!
w "工作经历Object：" _ ..work.workDateGet() _ " " _ ..work.companyGet(),!
}
/// d ##class(PHA.YX.Design.Program).PrototypeExampleShallow()
ClassMethod PrototypeExampleShallow()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
d mResumeA.SetWorkExperienceObject("2010-2011","腾讯")
# dim mResumeB as PHA.YX.Design.Prototype.Resume
s mResumeB = mResumeA.%ConstructClone()
d mResumeB.SetPersonalInfo("男","31")
d mResumeB.SetWorkExperienceObject("2011-2012","阿里")
# dim mResumeC as PHA.YX.Design.Prototype.Resume
s mResumeC =mResumeA.%ConstructClone()
d mResumeC.SetWorkExperience("2017-2020","SS公司")
d mResumeC.SetWorkExperienceObject("2012-2013","百度")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
DHC-APP> d ##class(PHA.YX.Design.Program).PrototypeExampleShallow()
姚鑫 男 30
工作经历：2015-2020 XX公司
工作经历Object：2012-2013 百度
姚鑫 男 31
工作经历：2015-2020 XX公司
工作经历Object：2012-2013 百度
姚鑫 男 30
工作经历：2017-2020 SS公司
工作经历Object：2012-2013 百度
结果发现。引用的字段并没有重新复制。
深复制
我们在PHA.YX.Design.Prototype.Resume里给work属性，增加一个克隆方法。
Method CloneWorkExperience()
{
s ..work = ..work.%ConstructClone()
}
/// d ##class(PHA.YX.Design.Program).PrototypeExampleDeep()
ClassMethod PrototypeExampleDeep()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
d mResumeA.CloneWorkExperience()
d mResumeA.SetWorkExperienceObject("2010-2011","腾讯")
# dim mResumeB as PHA.YX.Design.Prototype.Resume
s mResumeB = mResumeA.%ConstructClone()
d mResumeB.SetPersonalInfo("男","31")
d mResumeB.CloneWorkExperience()
d mResumeB.SetWorkExperienceObject("2011-2012","阿里")
# dim mResumeC as PHA.YX.Design.Prototype.Resume
s mResumeC =mResumeA.%ConstructClone()
d mResumeC.SetWorkExperience("2017-2020","SS公司")
d mResumeC.CloneWorkExperience()
d mResumeC.SetWorkExperienceObject("2012-2013","百度")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
结果发现，把引用字段work的值也修改成功。
DHC-APP>d ##class(PHA.YX.Design.Program).PrototypeExampleDeep()
姚鑫 男 30
工作经历：2015-2020 XX公司
工作经历Object：2010-2011 腾讯
姚鑫 男 31
工作经历：2015-2020 XX公司
工作经历Object：2011-2012 阿里
姚鑫 男 30
工作经历：2017-2020 SS公司
工作经历Object：2012-2013 百度
完整示例
简历类(复制类)
Class PHA.YX.Design.Prototype.Resume Extends %RegisteredObject
{
Property name As %String [ Private ];
Property sex As %String [ Private ];
Property age As %String [ Private ];
Property timeArea As %String [ Private ];
Property company As %String [ Private ];
Property work As WorkExperience [ Private ];
Method %OnNew(name As %String) As %Status [ Private, ServerOnly = 1 ]
{
s $this.name = name
s ..work = ##class(WorkExperience).%New()
Quit $$$OK
}
Method CloneWorkExperience()
{
s ..work = ..work.%ConstructClone()
}
Method SetPersonalInfo(sex As %String, age As %String)
{
s $this.sex=sex
s $this.age=age
}
Method SetWorkExperience(timeArea As %String, company As %String)
{
s $this.timeArea=timeArea
s $this.company=company
}
Method SetWorkExperienceObject(workDate As %String, company As %String)
{
d ..work.workDateSet(workDate)
d ..work.companySet(company)
}
Method Display()
{
w ..name _ " " _ ..sex _ " " _ ..age,!
w "工作经历：" _ ..timeArea _ " " _ ..company,!
w "工作经历Object：" _ ..work.workDateGet() _ " " _ ..work.companyGet(),!
}
}
对象类（工作经验类）
Class PHA.YX.Design.Prototype.WorkExperience Extends %RegisteredObject
{
Property workDate As %String [ Private ];
Method workDateGet() As %String [ ServerOnly = 1 ]
{
Quit i%workDate
}
Method workDateSet(Arg As %String) As %Status [ ServerOnly = 1 ]
{
s i%workDate = Arg
Quit $$$OK
}
Property company As %String [ Private ];
Method companyGet() As %String [ ServerOnly = 1 ]
{
Quit i%company
}
Method companySet(Arg As %String) As %Status [ ServerOnly = 1 ]
{
s i%company = Arg
Quit $$$OK
}
}
调用
/// d ##class(PHA.YX.Design.Program).PrototypeExamplePrimary()
ClassMethod PrototypeExamplePrimary()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
s mResumeB = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeB.SetPersonalInfo("男","30")
d mResumeB.SetWorkExperience("2015-2020","XX公司")
s mResumeC = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeC.SetPersonalInfo("男","30")
d mResumeC.SetWorkExperience("2015-2020","XX公司")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
/// d ##class(PHA.YX.Design.Program).PrototypeExampleIntermediate()
ClassMethod PrototypeExampleIntermediate()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
# dim mResumeB as PHA.YX.Design.Prototype.Resume
s mResumeB = mResumeA
d mResumeB.SetPersonalInfo("男","31")
# dim mResumeC as PHA.YX.Design.Prototype.Resume
s mResumeC = mResumeA
d mResumeC.SetWorkExperience("2017-2020","SS公司")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
/// d ##class(PHA.YX.Design.Program).PrototypeExampleSenior()
ClassMethod PrototypeExampleSenior()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
# dim mResumeB as PHA.YX.Design.Prototype.Resume
s mResumeB = mResumeA.%ConstructClone()
d mResumeB.SetPersonalInfo("男","31")
# dim mResumeC as PHA.YX.Design.Prototype.Resume
s mResumeC =mResumeA.%ConstructClone()
d mResumeC.SetWorkExperience("2017-2020","SS公司")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
/// d ##class(PHA.YX.Design.Program).PrototypeExampleShallow()
ClassMethod PrototypeExampleShallow()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
d mResumeA.SetWorkExperienceObject("2010-2011","腾讯")
# dim mResumeB as PHA.YX.Design.Prototype.Resume
s mResumeB = mResumeA.%ConstructClone()
d mResumeB.SetPersonalInfo("男","31")
d mResumeB.SetWorkExperienceObject("2011-2012","阿里")
# dim mResumeC as PHA.YX.Design.Prototype.Resume
s mResumeC =mResumeA.%ConstructClone()
d mResumeC.SetWorkExperience("2017-2020","SS公司")
d mResumeC.SetWorkExperienceObject("2012-2013","百度")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
/// d ##class(PHA.YX.Design.Program).PrototypeExampleDeep()
ClassMethod PrototypeExampleDeep()
{
s mResumeA = ##class(PHA.YX.Design.Prototype.Resume).%New("姚鑫")
d mResumeA.SetPersonalInfo("男","30")
d mResumeA.SetWorkExperience("2015-2020","XX公司")
d mResumeA.CloneWorkExperience()
d mResumeA.SetWorkExperienceObject("2010-2011","腾讯")
# dim mResumeB as PHA.YX.Design.Prototype.Resume
s mResumeB = mResumeA.%ConstructClone()
d mResumeB.SetPersonalInfo("男","31")
d mResumeB.CloneWorkExperience()
d mResumeB.SetWorkExperienceObject("2011-2012","阿里")
# dim mResumeC as PHA.YX.Design.Prototype.Resume
s mResumeC =mResumeA.%ConstructClone()
d mResumeC.SetWorkExperience("2017-2020","SS公司")
d mResumeC.CloneWorkExperience()
d mResumeC.SetWorkExperienceObject("2012-2013","百度")
d mResumeA.Display()
d mResumeB.Display()
d mResumeC.Display()
}
思考
用深复制实现，Java，Python，C#，连接Caché数据库（有连接属性，连接时间），Caché数据库持有SQL数据库连接（有连接属性，连接时间）。感兴趣的同学实现后可以发我一起参考下。
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