JAVA实验6答案

..GDOU-B-11-112 广东海洋大学学生实验报告书（学生用表）Java 程序设计与开发实验名称实验六. Java 的接口与实现课程名称技术课程号16232204 学院( 系) 信息学院专业计算机科学与技术班级计科钟海楼2015 年学生姓名学号实验地点04019 实验日期10 月26 日一、实验目的（1）学习掌握Java 中类怎样实现接口、接口回调技术；（2）学习掌握Java 程序中面向接口的编程思想。

二、实验任务完成实验六指导上实验1、实验2、实验3 的实验任务。

三、实验仪器设备和材料安装有J2SE开发工具的PC机。

四、实验内容和步骤实验 1代码如下：Estimator.javainterface CompurerAverage{public double average(double x[]);}class Gymnastics implementsCompurerAverage{ public doubleaverage(double x[]){int count=x.length;double aver=0,temp=0;for(int i=0;i<count;i++){for(intj=i;j<count;j++){ if(x[j]<x[i]){temp=x[j];x[j]=x[i];x[i]=temp;}}.. }for(int i=1;i<count-1;i++){aver=aver+x[i];}if(count>2)aver=aver/(count-2);elseaver=0;return aver;}}class School implementsCompurerAverage{ public doubleaverage(double[] x){int count=x.length;double sum=0;for(inti=0;i<count;i++){ sum+=x[i];}return sum/count;}}public class Estimator{public static void main(String[] args){double a[]={9.89,9.88,9.99,9.12,9.69,9.76,8.97};double b[]={89,56,78,90,100,77,56,45,36,79,98};CompurerAverage computer;computer=new Gymnastics();double result=computer.average(a);System.out.printf("%n");System.out.printf(" 体操选手最后得分：%5.3f\n",result);computer=new School();result=computer.average(b);System.out.printf(" 班级考试平均分数：%-5.2f\n",result);}}运行结果：练习：---------- JAVAC ----------Estimator.java:27: 错误: School 不是抽象的, 并且未覆盖CompurerAverage 中的抽象方法average(double[])class School implements CompurerAverage{^1 个错误实验 2代码如下：CheckCarWeight.javainterface ComputerWeight{public double computerWeight();}class Television implementsComputerWeight{ public doublecomputerWeight(){return 10.0;}}class Computer implementsComputerWeight{ public doublecomputerWeight(){return 8.0;}}class WashMachine implementsComputerWeight{ public doublecomputerWeight(){return 35.5;}}class Truck{ComputerWeight[] goods;double totalWeihts=0;Truck(ComputerWeight[] goods){this.goods=goods;}public void setGoods(ComputerWeight[]goods){ this.goods=goods;}public doublegetTotalWeigths(){ totalWeihts=0;for(inti=0;i<goods.length;i++){ totalWeihts+=go ods[i].computerWeight();}return totalWeihts;}}public class CheckCarWeight{public static void main(String[] args){ComputerWeight[] goods=new ComputerWeight[650];for(int i=0;i<goods.length;i++){if(i%3==0)goods[i]=new Television();if(i%3==1)goods[i]=new Computer();if(i%3==2)goods[i]=new WashMachine();}Truck truck=new Truck(goods);System.out.printf("\n 货车装载的货物重量：%-8.5f kg\n",truck.getTotalWeigths());goods=new ComputerWeight[68];for(int i=0;i<goods.length;i++){if(i%2==0)goods[i]=new Television();elsegoods[i]=new WashMachine();}truck.setGoods(goods);System.out.printf(" 货车装载的货物重量：%-8.5f kg\n",truck.getTotalWeigths());}}运行结果：练习：class Refrigerrator implementsComputerWeight{ public doublecomputerWeight(){return 10.5;}}不需修改Truck 类实验 3代码如下：CheckDogState.javainterface DogState{public void showState();}class SoftlyState implementsDogState{ public void showState(){System.out.println(" 听主人的命令");}}class MeetEnemyState implementsDogState{ public void showState(){System.out.println(" 狂叫，并冲向去狠咬敌人");}}class MeetFriendState implementsDogState{ public void showState(){System.out.println(" 晃动尾巴，表示欢迎");}}class MeetAnotherDog implementsDogState{ public void showState(){System.out.println(" 嬉戏");}}class Dog{DogState state;public void show(){state.showState();}public void setState(DogStates){ state=s;}}public class CheckDogState{public static void main(String[]args){ Dog yellowDog=newDog();System.out.print(" 狗在主人面前：");yellowDog.setState(new SoftlyState());yellowDog.show();System.out.print(" 狗遇到敌人：");yellowDog.setState(new MeetEnemyState());yellowDog.show();System.out.print(" 狗遇到朋友：");yellowDog.setState(new MeetFriendState());yellowDog.show();System.out.print(" 狗遇到同伴：");yellowDog.setState(new MeetAnotherDog());yellowDog.show();}}运行结果：练习：CheckWaterState.javainterface WaterState{public void showState();}class ColdState implementsWaterState{ public voidshowState(){System.out.println(" 固态");}}class OrdinaryState implementsWaterState{ public void showState(){System.out.println(" 液态");}}class HotState implementsWaterState{ public voidshowState(){System.out.println(" 气态");} }..;.. class Water{WaterState state;public void show(){state.showState();}public void setState(WaterStates){ state=s;}}public class CheckWaterState{public static void main(String[]args){ Water water=new Water();System.out.print(" 低于0°C：");water.setState(new ColdState());water.show();System.out.print(" 高于0°C 且低于100°C：");water.setState(new OrdinaryState());water.show();System.out.print(" 高于100°C：");water.setState(new HotState());water.show();}}成绩指导教师孙兵日期2015 年10 月30 日注:请用A4 纸书写，不够另附纸。