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一、概述

       原型模式（ProtoType），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。 

二、UML图示

三、编程实现

       该程序主要通过模拟复制简历的功能实现。

1、具体原型类

public class Resume implements Cloneable {    private String name;    private int age;    private String sex;    private String timeArea;    private String company;    public Resume(String name) {        this.name = name;    }    /**     * 设置个人信息     * @param sex     * @param age     */    public void setPersonInfo(String sex,int age){        this.sex = sex;        this.age = age;    }    /**     * 设置工作经历     * @param timeArea     * @param company     */    public void setWorkExperience(String timeArea,String company){        this.timeArea = timeArea;        this.company = company;    }    public void display(){        System.out.println(this.name + ","+this.sex+","+this.age);        System.out.println(this.timeArea+","+this.company);    }    public Object clone(){        Resume resume = null;        try {           resume =(Resume) super.clone();        }catch (CloneNotSupportedException e){            System.out.println(e);        }        return resume;    }}

2、测试类

public class Test {    public static void main(String[] args) {        Resume resume1 = new Resume("aa");        resume1.setPersonInfo("male",25);        resume1.setWorkExperience("2015-2018","xx公司");        Resume resume2 = (Resume) resume1.clone();        resume2.setWorkExperience("2015-2018","yy公司");        Resume resume3 = (Resume)resume1.clone();        resume3.setPersonInfo("female",29);        resume1.display();        resume2.display();        resume3.display();    }}输出：aa,male,252015-2018,xx公司aa,male,252015-2018,yy公司aa,female,292015-2018,xx公司

        在初始化信息不变的情况下，克隆是最好的办法。既隐藏了对象创建的细节，又大大提高了性能。

        存在问题：

               clone()方法中，如果字段是值类型，则对该字段进行逐位复制，如果该字段是引用类型，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同一对象。

四、浅复制编程问题

1、封装工作经历类

public class WorkExperience {    private String timeArea;    private String company;    public String getTimeArea() {        return timeArea;    }    public void setTimeArea(String timeArea) {        this.timeArea = timeArea;    }    public String getCompany() {        return company;    }    public void setCompany(String company) {        this.company = company;    }}

2、resume类修改

public class Resume implements Cloneable {    private String name;    private int age;    private String sex;    private WorkExperience workExperience;    public Resume(String name) {        this.name = name;        workExperience = new WorkExperience();    }    /**     * 设置个人信息     * @param sex     * @param age     */    public void setPersonInfo(String sex,int age){        this.sex = sex;        this.age = age;    }    /**     * 设置工作经历     * @param timeArea     * @param company     */    public void setWorkExperience(String timeArea,String company){        workExperience.setTimeArea(timeArea);;        workExperience.setCompany(company);    }    public void display(){        System.out.println(this.name + ","+this.sex+","+this.age);        System.out.println(workExperience.getTimeArea()+","+workExperience.getCompany());    }    public Object clone(){        Resume resume = null;        try {           resume =(Resume) super.clone();        }catch (CloneNotSupportedException e){            System.out.println(e);        }        return resume;    }}

3、测试类

public class Test {    public static void main(String[] args) {        Resume resume1 = new Resume("aa");        resume1.setPersonInfo("male",25);        resume1.setWorkExperience("2015-2018","xx公司");        Resume resume2 = (Resume) resume1.clone();        resume2.setWorkExperience("2015-2018","yy公司");        Resume resume3 = (Resume)resume1.clone();        resume3.setPersonInfo("female",29);        resume1.display();        resume2.display();        resume3.display();    }}输出：aa,male,252015-2018,yy公司aa,male,252015-2018,yy公司aa,female,292015-2018,yy公司

可以看出输出的都是yy公司，存在浅复制问题。

“浅复制”，即被复制对象所有变量都含有与原来对象相同的值，而所有的对其他对象的引用仍然指向原来的对象。而“深复制”则可把引用对象的变量指向复制过的新对象，而不是原来对象。

五、深复制实现

1、工作经历类实现cloneable接口，并重写clone方法

public class WorkExperience implements Cloneable{    private String timeArea;    private String company;    public String getTimeArea() {        return timeArea;    }    public void setTimeArea(String timeArea) {        this.timeArea = timeArea;    }    public String getCompany() {        return company;    }    public void setCompany(String company) {        this.company = company;    }    public Object clone(){        WorkExperience workExperience = null;        try {            workExperience =(WorkExperience) super.clone();        }catch (CloneNotSupportedException e){            System.out.println(e);        }        return workExperience;    }}

2、简历类修改

public class Resume implements Cloneable {    private String name;    private int age;    private String sex;    private WorkExperience workExperience;    public Resume(String name) {        this.name = name;        this.workExperience = new WorkExperience();    }    private Resume(WorkExperience workExperience){        this.workExperience = (WorkExperience) workExperience.clone();    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    /**     * 设置个人信息     * @param sex     * @param age     */    public void setPersonInfo(String sex,int age){        this.sex = sex;        this.age = age;    }    /**     * 设置工作经历     * @param timeArea     * @param company     */    public void setWorkExperience(String timeArea,String company){        this.workExperience.setTimeArea(timeArea);;        this.workExperience.setCompany(company);    }    public void display(){        System.out.println(this.name + ","+this.sex+","+this.age);        System.out.println(workExperience.getTimeArea()+","+workExperience.getCompany());    }    public Object clone(){        Resume resume = new Resume(this.workExperience);        resume.setPersonInfo(this.sex,this.age);        resume.setName(this.name);        return resume;    }}

3、测试

public class Test {    public static void main(String[] args) {        Resume resume1 = new Resume("aa");        resume1.setPersonInfo("male",25);        resume1.setWorkExperience("2015-2018","xx公司");        Resume resume2 = (Resume) resume1.clone();        resume2.setWorkExperience("2015-2018","yy公司");        Resume resume3 = (Resume)resume1.clone();        resume3.setPersonInfo("female",29);        resume1.display();        resume2.display();        resume3.display();    }}输出：aa,male,252015-2018,xx公司aa,male,252015-2018,yy公司aa,female,292015-2018,xx公司

注：参考文献《大话设计模式》程杰著。