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增加原型模式的示例代码
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‎src/com/company/prototype/Client.java‎

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package com.company.prototype;
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public class Client {
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public static void main(String[] args) {
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// WordDocument originDoc =new WordDocument();
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WordDocument2 originDoc = new WordDocument2();
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originDoc.setText("这是一篇文档");
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originDoc.addImage("图片1");
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originDoc.addImage("图片2");
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originDoc.addImage("图片3");
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originDoc.showDocument();
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// WordDocument doc2 = originDoc.clone();
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WordDocument2 doc2 = originDoc.clone();
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doc2.showDocument();
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doc2.setText("这是修改过的文档");
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doc2.addImage("哈哈.png");
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doc2.showDocument();
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originDoc.showDocument();
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}
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}

‎src/com/company/prototype/WordDocument.java‎

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package com.company.prototype;
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import java.util.ArrayList;
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/**
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* 文档类型，代表ConcretePrototype Cloneable代表prototype角色，生命具备clone的能力
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*/
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public class WordDocument implements Cloneable {
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private String text;//文本
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private ArrayList<String> images = new ArrayList<>();//图片
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public WordDocument() {
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System.out.println("--------WordDocument的构造函数--------");
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}
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public String getText() {
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return text;
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}
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public void setText(String text) {
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this.text = text;
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}
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public ArrayList<String> getImages() {
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return images;
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}
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public void addImage(String image) {
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this.images.add(image);
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}
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@Override
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protected WordDocument clone() {
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try {
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WordDocument wordDocument = (WordDocument) super.clone();//返回新的对象
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wordDocument.text = this.text;
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wordDocument.images = this.images;
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return wordDocument;
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} catch (Exception e) {
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e.printStackTrace();
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}
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return null;
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}
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public void showDocument() {
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System.out.println("--------Word Content Start--------");
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System.out.println("Text: " + text);
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System.out.println("Image lists");
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for (String imageName : images) {
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System.out.println("Image name: " + imageName);
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}
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System.out.println("--------Word Content End--------");
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}
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}

‎src/com/company/prototype/WordDocument2.java‎

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package com.company.prototype;
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import java.util.ArrayList;
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/**
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* 文档类型，代表ConcretePrototype Cloneable代表prototype角色，生命具备clone的能力
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*/
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public class WordDocument2 implements Cloneable {
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private String text;//文本
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private ArrayList<String> images = new ArrayList<>();//图片
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public WordDocument2() {
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System.out.println("--------WordDocument的构造函数--------");
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}
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public String getText() {
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return text;
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}
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public void setText(String text) {
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this.text = text;
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}
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public ArrayList<String> getImages() {
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return images;
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}
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public void addImage(String image) {
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this.images.add(image);
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}
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@Override
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protected WordDocument2 clone() {
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try {
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WordDocument2 wordDocument = (WordDocument2) super.clone();//返回新的对象
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wordDocument.text = this.text;
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// 对对象的引用数据类型，采用clone（），进行深拷贝
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wordDocument.images = (ArrayList<String>) this.images.clone();
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return wordDocument;
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} catch (Exception e) {
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e.printStackTrace();
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}
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return null;
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}
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public void showDocument() {
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System.out.println("--------Word Content Start--------");
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System.out.println("Text: " + text);
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System.out.println("Image lists");
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for (String imageName : images) {
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System.out.println("Image name: " + imageName);
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}
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System.out.println("--------Word Content End--------");
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}
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}

‎src/com/company/prototype/login/Address.java‎

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package com.company.prototype.login;
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public class Address {
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public String city;
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public String district;
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public String street;
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public Address(String city, String district, String street) {
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this.city = city;
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this.district = district;
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this.street = street;
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}
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@Override
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public String toString() {
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return "Address{" +
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"city='" + city + '\'' +
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", district='" + district + '\'' +
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", street='" + street + '\'' +
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'}';
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}
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}

‎src/com/company/prototype/login/Login.java‎

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package com.company.prototype.login;
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public interface Login {
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void login();
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}

‎src/com/company/prototype/login/LoginImpl.java‎

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package com.company.prototype.login;
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public class LoginImpl implements Login {
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@Override
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public void login() {
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// 登陆到服务器，获取用户信息
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User user = new User();
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// 将服务器返回的信息设置给loginUser
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user.age = 22;
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user.name = "Night";
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user.phoneNum = "12685699865";
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user.address = new Address("南阳", "西峡", "二郎坪");
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// 登陆完成之后将用户信息设置懂啊LoginSession中
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LoginSession loginSession = LoginSession.getLoginSession();
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loginSession.setLoginUser(user);//因为setLoginSession（）为包级私有，外部module无法调用
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}
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}

‎src/com/company/prototype/login/LoginSession.java‎

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package com.company.prototype.login;
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//登陆session
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public class LoginSession {
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static LoginSession loginSession = null;
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private User loginUser;//当前登陆的用户信息
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private LoginSession() {
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}
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public static LoginSession getLoginSession() {
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if (loginSession == null) {
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loginSession = new LoginSession();
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}
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return loginSession;
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}
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public User getLoginUser() {
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// return loginUser;
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return loginUser.clone();
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}
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// 设置已经登陆的用户信息，不对外开放，包级私有
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void setLoginUser(User user) {
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this.loginUser = user;
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}
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}

‎src/com/company/prototype/login/Test.java‎

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package com.company.prototype.login;
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//登陆测试类
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public class Test {
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public static void main(String[] args) {
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// User curUser = LoginSession.getLoginSession().getLoginUser();
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User curUser = new User();
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// 将服务器返回的信息设置给loginUser
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curUser.age = 22;
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curUser.name = "Night";
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curUser.phoneNum = "12685699865";
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curUser.address = new Address("南阳", "西峡", "二郎坪");
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System.out.println("用户原始的信息：");
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System.out.println(curUser);
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curUser.address = new Address("南京", "建邺", "油坊桥");
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System.out.println("用户现在的信息：");
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System.out.println(curUser);
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}
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}

‎src/com/company/prototype/login/User.java‎

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package com.company.prototype.login;
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public class User implements Cloneable {
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public int age;
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public String name;
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public String phoneNum;
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public Address address;
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@Override
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public String toString() {
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return "User{" +
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"age=" + age +
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", name='" + name + '\'' +
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", phoneNum='" + phoneNum + '\'' +
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", address=" + address +
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'}';
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}
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@Override
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protected User clone() {
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User user = null;
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try {
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user = (User) super.clone();
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} catch (CloneNotSupportedException e) {
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e.printStackTrace();
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}
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return user;
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}
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}

‎src/com/company/prototype/summary.txt‎

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原型模式：
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它是一个创建型模式。原型表明该模式应该有一个样板实例。用户从这个样板实例中复制出一个内部属性一直的对象，即克隆。
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被复制的对象就是“原型”。
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目的：原型模式定义用于创建复杂的或者构造耗时的实例，复制一个已经存在的实例可以使程序运行更加高效
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使用场景：
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1.类初始化需要消耗很多资源，这个资源包括数据、硬件资源等。通过原型拷贝避免消耗
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2.通过new产生一个对象需要非常繁琐的数据准备或者访问权限，原型模式可以避免
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3.提供保护性拷贝
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注意：通过实现Cloneable接口的原型模式在调用clone函数构造实例时并不一定比通过new操作更快，只有当通过new操作更
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耗时或者消耗资源的时候，通过clone方法才能获得效率上的提升。因此使用的时候要做比较
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角色介绍：
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Client 客户端用户
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Prototype 抽象类或者接口 生命具备clone的能力
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ConcretePrototype 具体的原型类
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注意clone方法并不是Cloneable接口中的，它是一个标识接口，表明这个类是可以拷贝的。而具体的拷贝来自于Object
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的clone（）。没有生命这个接口的类调用了clone（）会报错
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通过clone拷贝对象，并不会执行其构造方法
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浅拷贝和深拷贝：
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浅拷贝：原始类型的字段根据原数据重新构建，引用类型数据直接指向原数据的引用
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深拷贝：对于引用类型的数据，拷贝对象的时候，也要采用拷贝的形式。不能是单纯的引用
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优点：是在内存中的二进制流的拷贝，要比直接new一个对象性能更好，特别是在一个循环体内需要产生大量对象的时候，
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原型模式更能体现其优点
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缺点：直接在内存中拷贝，构造函数不执行
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安卓中的应用：ArrayList Intent的查找和匹配。注意此处Intent的拷贝用的是new 方法

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