1、實(shí)驗(yàn)二 繼承與接口一、實(shí)驗(yàn)?zāi)康?. 掌握類的繼承機(jī)制。2. 熟悉類中成員變量和方法的訪問(wèn)控制。3. 掌握接口與包的使用，熟悉方法的多態(tài)性。二、實(shí)驗(yàn)內(nèi)容1. 定義父類及子類，在子類中重寫父類的方法2. 練習(xí)接口與包的使用三、.實(shí)驗(yàn)步驟與要求第1題 繼承編寫一個(gè)Java應(yīng)用程序，除了主類外，該程序中還有4個(gè)類：People, ChinaPeople, AmericanPeople 和 BeijingPeople類。此四個(gè)類的繼承關(guān)系如下圖所示：要求ChinaPeople，American類均重寫其父類People類的speakHello, averageHeight, averageWeight方

2、法，BeijingPeople類重寫其父類ChinaPeople類的speakHello, averageHeight, averageWeight方法。People類 變量 方法protected double height public void speak Hello() protected double weight public void averageHeight() public void averageWeight()ChinaPeople類方法： public void chinaGongfu()AmericanPeople類方法：Public void americanBo

3、xing()BeijingPeople類方法：Public void beijingOpera()源代碼：package people;class peopleprotected double height ; protected double weight ; 請(qǐng)預(yù)覽后下載！public void speakHello() /問(wèn)候語(yǔ)的函數(shù)System.out.println(hello);public void averageHeight()/人們的平均身高 height=170;System.out.println(+height);public void averageWeight()/

4、人們的平均體重 weight=120;System.out.println(+weight);class Chinapeople extends peoplepublic void speakHello() System.out.println(你好);public void averageHeight() height=172;System.out.println(+height);public void averageWeight() weight=115;System.out.println(+weight);public void chinaGongfu()/中國(guó)功夫的方法System

5、.out.println(中國(guó)功夫);class Americanpeople extends peoplepublic void speakHello() System.out.println(hello);public void averageHeight()請(qǐng)預(yù)覽后下載！ height=180;System.out.println(+height);public void averageWeight() weight=150;System.out.println(+weight);public void americanBoxing()/美國(guó)拳擊的方法System.out.println

6、(americanBoxing);class Beijingpeople extends Chinapeoplepublic void speakHello() System.out.println(北京歡迎你);public void averageHeight() height=168;System.out.println(+height);public void averageWeight() weight=125;System.out.println(+weight);class Examplepublic static void main(String args)people p =

7、new people();Chinapeople c=new Chinapeople();Americanpeople a=new Americanpeople();Beijingpeople b=new Beijingpeople();p.averageHeight();p.averageWeight();p.speakHello();c.averageHeight();c.averageWeight();c.chinaGongfu();請(qǐng)預(yù)覽后下載！c.speakHello();a.averageHeight();a.averageWeight();a.americanBoxing();a

8、.speakHello();b.averageHeight();b.averageWeight();b.speakHello();結(jié)果截圖：第2題 上轉(zhuǎn)型對(duì)象要求有一個(gè)abstract類，類名為Employee。Employee的子類有YearWorker,MonthWorker和WeekWorker。YearWorker按年領(lǐng)取薪水，MonthWorker按月領(lǐng)取薪水，WeekWorker按周領(lǐng)取薪水。Employee類有一個(gè)abstract方法：public abstract earnings();子類必須重寫父類的earnings()方法，給出各自領(lǐng)取報(bào)酬的具體方式。有一個(gè)Company

9、類，該類用employee數(shù)組作為成員，employee數(shù)組的單元可以是YearWorker對(duì)象的上轉(zhuǎn)型對(duì)象、MonthWorker對(duì)象的上轉(zhuǎn)型對(duì)象或WeekWorker對(duì)象的上轉(zhuǎn)型對(duì)象。程序能輸出Company對(duì)象一年需要支付的薪水總額。源代碼：package people; abstract class Employee請(qǐng)預(yù)覽后下載！ int salary;public abstract void earnings();class YearWorker extends Employee public void earnings() salary=200;System.out.println

10、(年薪： +salary*365);class MonthWorker extends Employee public void earnings() salary=100;System.out.println(月薪：+salary*30+ 一年薪水： +salary*30*12);class WeekWorker extends Employee public void earnings() salary=80;System.out.println(周薪：+salary*7+ 一年薪水： +salary*365);public class Company public static void

11、 main(String args) Employee e=new Employee3; e0=new YearWorker(); e0.earnings(); e1=new MonthWorker(); e1.earnings(); e2=new WeekWorker(); e2.earnings(); 結(jié)果截圖：請(qǐng)預(yù)覽后下載！第3題 接口回調(diào)要求有一個(gè)ComputeTotalSales接口，該接口中有一個(gè)方法：public double totalSalesByYear()，有三個(gè)實(shí)現(xiàn)該接口的類：Television,Computer和Mobile。這三個(gè)類通過(guò)實(shí)現(xiàn)接口computeTot

12、alSales，給出自己的年銷售額。有一個(gè)Shop類，該類用computeTotalSales數(shù)組作為成員，computeTotalSales數(shù)組的單元可以存放Television對(duì)象的引用、Computer對(duì)象的引用或Mobile對(duì)象的引用。程序能輸出Shop對(duì)象的年銷售額。源代碼：package people;interface ComputeTotalSalespublic double totalSalesByYear();class Television implements ComputeTotalSalespublic double totalSalesByYear()doubl

13、e sale=100;return sale*365;class computer implements ComputeTotalSalespublic double totalSalesByYear()double sale=200;return sale*365;class Mobile implements ComputeTotalSalespublic double totalSalesByYear()double sale=220;return sale*365;請(qǐng)預(yù)覽后下載！public class shop public static void main(String args) ComputeTotalSales c; c=new ComputeTotalSales3; c0=new Television(); System.out.println(電視機(jī)的年銷售量：+c0.totalSalesByYear(); c1=new computer(); System.out.println(電腦的年銷售量：+c1.totalSalesByYear(); c2=new Mobile(); System.out.pri