設(shè)計(jì)模式原型模式

第五章原型模式五.一問(wèn)題地提出五.二原型模式五.三原型復(fù)制具體實(shí)現(xiàn)方法五.四應(yīng)用示例五.一問(wèn)題地提出在計(jì)算機(jī)程序開(kāi)發(fā)過(guò)程,有時(shí)會(huì)遇到為一個(gè)類創(chuàng)建多個(gè)實(shí)例地情況,這些實(shí)例內(nèi)部成員往往完全相同或有細(xì)微地差異,而且實(shí)例地創(chuàng)建開(kāi)銷比較大或者需要輸入較多參數(shù),如果能通過(guò)復(fù)制一個(gè)已創(chuàng)建地對(duì)象實(shí)例來(lái)重復(fù)創(chuàng)建多個(gè)相同地對(duì)象,這就可以大大減少創(chuàng)建對(duì)象地開(kāi)銷,這個(gè)時(shí)候就需要原型模式。一.淺復(fù)制。五.二原型模式二.深復(fù)制。五.三原型復(fù)制具體實(shí)現(xiàn)方法考慮學(xué)生對(duì)象復(fù)制問(wèn)題。classStudent{ Stringname; //姓名 intage; //年齡 Addressadd; //籍貫信息 Student(Stringna,inta,Addressadd){ =na; age=a; this.add=add; } publicStringgetName(){returnname;} publicvoidsetName(Stringname){=name;} publicintgetAge(){returnage;} publicvoidsetAge(intage){this.age=age;} publicAddressgetAdd(){returnadd;} publicvoidsetAdd(Addressadd){this.add=add;} }classAddress{ Stringpro; //出生省 Stringcity; //出生市 Stringzip; //出生地郵編 publicAddress(Stringp,Stringc,Stringz){ pro=p;city=c;zip=z; } publicStringgetPro(){returnpro;} publicvoidsetPro(Stringpro){=pro;} publicStringgetCity(){returncity;} publicvoidsetCity(Stringcity){this.city=city;} publicStringgetZip(){returnzip;} publicvoidsetZip(Stringzip){this.zip=zip;} }五.三.一構(gòu)造函數(shù)方法(一)淺復(fù)制。 publicclassStudent{ //其它所有代碼同五.三,略 Student(Students){ name=s.getName(); age=s.getAge(); add=s.getAdd(); }}(二)深復(fù)制。classAddress{ //其它所有代碼同五.三,略 publicAddress(Addressadd){ pro=add.getPro(); city=add.getCity(); zip=add.getZip(); }}classStudent{ //其它所有代碼同五.三,略 Student(Students){ name=s.getName(); age=s.getAge(); add=newAddress(s.getAdd()); }}五.三.二利用Cloneable接口方法（一）淺復(fù)制。publicclassStudentimplementsCloneable{ //其它代碼同五.三 protectedObjectclone()throwsCloneNotSupportedException{ returnsuper.clone(); } }（二）深復(fù)制。

classAddressimplementsCloneable{

//其它代碼同五.三

protectedObjectclone()throwsCloneNotSupportedException{

Addresss=(Address)super.clone();

returns;

}

}

classStudentimplementsCloneable{

//其它代碼同五.三

protectedObjectclone()throwsCloneNotSupportedException{

Students=(Student)super.clone();

s.setAdd((Address)add.clone());

returns;

}

}五.三.三利用Serializable序列化接口方法classAddressimplementsSerializable{ //其它代碼同五.三}classStudentimplementsCloneable,Serializable{ //其它代碼同六.三 protectedObjectclone()throwsCloneNotSupportedException{ Objectobj=null; try{ ByteArrayOutputStreambos=newByteArrayOutputStream(); ObjectOutputStreamoos=newObjectOutputStream(bos); oos.writeObject(this); //從流里讀回來(lái) ByteArrayInputStreambis=newByteArrayInputStream(bos.toByteArray()); ObjectInputStreamois=newObjectInputStream(bis); obj=ois.readObject(); } catch(Exceptione){e.printStackTrace();} returnobj; } }五.四應(yīng)用示例例五-一原型管理器及其應(yīng)用。importjava.util.*;classPrototypeManager{//定義一個(gè)Hashtable,用于存儲(chǔ)原型對(duì)象privateHashtableht=newHashtable();privatestaticPrototypeManagerpm=newPrototypeManager();publicvoidaddPrototype(Stringkey,Objectobj){ht.put(key,obj);}publicObjectgetPrototype(Stringkey){returnht.get(key);}publicstaticPrototypeManagergetPrototypeManager(){returnpm;}}例如:以學(xué)生基本信息為例,但內(nèi)容與五.三節(jié)有所不同,基本類如下所示。publicclassStudentimplementsCloneable{ Stringname;//學(xué)生姓名 intage; //年齡 PubInfoinfo; //公信息 publicStringgetName(){returnname;} publicvoidsetName(Stringname){=name;} publicintgetAge(){returnage;} publicvoidsetAge(intage){this.age=age;} publicPubInfogetInfo(){returninfo;} publicvoidsetInfo(PubInfoinfo){=info;} protectedObjectclone()throwsCloneNotSupportedException {returnsuper.clone();} }classPubInfoimplementsCloneable{ Stringcollege; //所在大學(xué) Stringcity; //所在城市 Stringzip; //郵編 publicPubInfo(Stringco,Stringc,Stringz){ college=co;city=c;zip=z; } publicStringgetCollege(){returncollege;} publicvoidsetCollege(Stringcollege){this.college=college;} publicStringgetCity(){returncity;} publicvoidsetCity(Stringcity){this.city=city;} publicStringgetZip(){returnzip;} publicvoidsetZip(Stringzip){this.zip=zip;} protectedObjectclone()throwsCloneNotSupportedException {returnsuper.clone();}}測(cè)試類地具體代碼如下所示。importjava.util.*;publicclassTest{ publicstaticvoidmain(String[]args)throwsException{ intm=一零,n=一零; PrototypeManagerpm=PrototypeManager.getPrototypeManager(); PubInfop=newPubInfo("liaoshi","dalian","一一六零八一"); Students=newStudent(); //創(chuàng)建遼師學(xué)生原型對(duì)象 s.setInfo(p); pm.addPrototype("liaoshi",s); //加入原形管理器 PubInfop二=newPubInfo("dagong","dalian","一一六零二三"); Students二=newStudent(); //創(chuàng)建大工學(xué)生原型對(duì)象 s二.setInfo(p二); pm.addPrototype("dagong",s二); //加入原形管理器

Scannersc=newScanner(System.in); Vector<Student>vec=newVector(); //創(chuàng)建遼師學(xué)生集合 Studentt=(Student)pm.getPrototype("liaoshi");//獲取原型對(duì)象 for(inti=零;i<m;i++){ Studentst=(Student)t.clone(); //通過(guò)淺復(fù)制創(chuàng)建新學(xué)生對(duì)象 st.setName(sc.nextLine()); //輸入并設(shè)置姓名 st.setAge(sc.nextInt()); //輸入并設(shè)置年齡