2021级-JAVA06 继承和多态、抽象类和接口
祁飞翰
6-1 创建一个直角三角形类实现IShape接口
class RTriangle implements IShape
{
double a, b;
public RTriangle (double a, double b)
{
super();
this.a = a;
this.b = b;
}
@Override
public double getArea() {
return 0.5*a*b;
}
@Override
public double getPerimeter() {
return a + b + Math.sqrt(a*a+b*b);
}
}6-2 从抽象类shape类扩展出一个圆形类Circle
class Circle extends shape
{
private double radius;
public Circle(double radius) {
this.radius = radius;
}
@Override
public double getArea() {
return Math.PI*radius*radius;
}
@Override
public double getPerimeter() {
return 2*Math.PI*radius;
}
}6-3 模拟题： 重写父类方法equals
public boolean equals(Object o)
{
Point p = (Point)o;
if(this.xPos==p.xPos&&this.yPos==p.yPos)
{
return true;
}
return false;
}6-4 重写父类方法equals
public boolean equals(Object o)
{
if (this == o)
{
return true;
}
if (o instanceof Student)
{
Student s = (Student) o;
if (s.id == this.id)
return true;
return false;
}
return false;
}6-5 根据派生类写出基类（Java）
public People(String id, String name) {
this.id = id;
this.name = name;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public People(){}
public void say()
{
System.out.println("I'm a person! My name is " + this.name + ".");
}6-6 写出派生类构造方法（Java）
super(id, name);
this.sid = sid;
this.score = score;6-7 设计一个Duck类及其子类
abstract class Duck
{
public void quack()
{
System.out.println("我会呱呱呱");
}
public void swim() {
System.out.println("我会游泳");
}
public void fly() {
System.out.println("我会飞");
}
abstract public void display();
}
class RedheadDuck extends Duck
{
public void display()
{
System.out.println("我是一只红头鸭");
}
}
class MallardDuck extends Duck {
public void display() {
System.out.println("我是一只绿头鸭");
}
}6-8 八边形Octagan类（接口）
interface Comparable<Octagon>
{
int compareTo(Octagon o);
}
interface Cloneable
{
Object clone();
}
class Octagon implements Comparable<Octagon>, Cloneable
{
private double side;
public Octagon(double side) {
this.side = side;
}
public double getSide() {
return side;
}
public void setSide(double side) {
this.side = side;
}
public double getPerimeter()
{
return this.getSide()*8;
}
public double getArea()
{
return (2+4/Math.sqrt(2))*this.getSide()*this.getSide();
}
public int compareTo(Octagon o)
{
if(this.getSide() > o.getSide())
return 1;
else if(this.getSide() < o.getSide())
return -1;
else if(this.getSide()==o.getSide())
return 0;
return 0;
}
public Object clone()
{
return new Octagon(side);
}
}6-9 使用继承设计：教师类。
class Teacher extends Person
{
String place;
public Teacher(String name, int age, String place) {
super(name, age);
this.place = place;
}
void work()
{
System.out.println("教师的工作是教学。");
}
void show()
{
super.show();
System.out.println(place);
}
}6-10 设计一个Triangle类继承自GeometricObject类
class Triangle extends GeometricObject
{
double side1, side2, side3;
public Triangle(double side1, double side2, double side3) {
this.side1 = side1;
this.side2 = side2;
this.side3 = side3;
}
public Triangle(String color, boolean filled, double side1, double side2, double side3) {
super(color, filled);
this.side1 = side1;
this.side2 = side2;
this.side3 = side3;
}
double getArea()
{
return Math.sqrt((side1+side2+side3)*(side1+side2-side3)*(side1-side2+side3)*(-side1+side2+side3))/4;
}
double getPerimeter()
{
return side1 + side2 + side3;
}
@Override
public String toString() {
return "Triangle: side1="+side1+" side2="+side2+" side3="+side3;
}
}
6-11 普通账户和支票账户
class Account
{
private int id;
private int balance;
public Account() {
}
public Account(int id, int balance) {
this.id = id;
this.balance = balance;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getBalance() {
return balance;
}
public void setBalance(int balance) {
this.balance = balance;
}
public boolean withdraw(int money)
{
if(balance < money)
{
return false;
}
else
{
balance = balance - money;
return true;
}
}
void deposit(int money)
{
this.balance += money;
}
@Override
public String toString() {
return "The balance of account "+id+" is "+this.balance;
}
}
class CheckingAccount extends Account
{
private int overdraft;
public CheckingAccount(int overdraft) {
this.overdraft = overdraft;
}
public CheckingAccount(int id, int balance, int overdraft) {
super(id, balance);
this.overdraft = overdraft;
}
public boolean withdraw(int money)
{
if(money > (overdraft + this.getBalance()))
{
return false;
}
else
{
this.setBalance(this.getBalance() - money);
return true;
}
}
}6-12 设计Worker类及其子类
class Worker
{
String name;
double rate;
public Worker(String name, double rate) {
this.name = name;
this.rate = rate;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getRate() {
return rate;
}
public void setRate(double rate) {
this.rate = rate;
}
public void pay(int hour)
{
System.out.println("Not Implemented");
}
}
class HourlyWorker extends Worker
{
public HourlyWorker(String name, double rate)
{
super(name, rate);
}
public void pay(int hour)
{
if(hour > 40)
{
System.out.println(rate * 40 + (hour - 40) * 2 * rate);
}
else
System.out.println(1.0 * hour * rate);
}
}
class SalariedWorker extends Worker
{
public SalariedWorker(String name, double rate) {
super(name, rate);
}
public void pay(int hour)
{
pay();
}
public void pay()
{
System.out.println(40.0*rate);
}
}6-13 图书和音像租赁
class Media
{
String name;
public double getDailyRent()
{
return 0.0;
}
}
class Book extends Media
{
double price;
public Book(String name, double price)
{
this.price = price;
this.name = name;
}
public double getDailyRent() {
return 0.01 * price;
}
}
class DVD extends Media
{
public DVD(String name)
{
this.name = name;
}
@Override
public double getDailyRent() {
return 1;
}
}
class MediaShop
{
public static double calculateRent(Media[] medias, int days)
{
double sum = 0;
for(int i = 0; i < medias.length; i ++)
{
sum += medias[i].getDailyRent()*days;
}
return sum;
}
}6-14 使用继承，实现“剪刀石头布的游戏”
class ComputerPlayer extends Player
{
public ComputerPlayer(String name) {
super(name);
}
}
class PersonPlayer extends Player
{
public PersonPlayer(String name) {
super(name);
}
int choice()
{
Scanner cin = new Scanner(System.in);
int c = cin.nextInt();
return c;
}
}
class Game
{
ComputerPlayer cp;
PersonPlayer pp;
public Game(ComputerPlayer cp, PersonPlayer pp) {
this.cp = cp;
this.pp = pp;
}
void start()
{
int c = cp.show();
int p = pp.choice();
if(c == p)
System.out.println("A Draw.");
else if(c == 1 && p == 3)
{
System.out.println("Winner is computerPlayer.");
}
else if(c == 3 && p == 1)
{
System.out.println("Winner is personPlayer.");
}
else if(p < c)
{
System.out.println("Winner is computerPlayer.");
}
else System.out.println("Winner is personPlayer.");
}
}6-15 教师、学生排序
class MyTool{
public static void separateStu_T(List persons,List teachers,List students){
Iterator It = persons.iterator();
while( It.hasNext()){
Person p= (Person) It.next();
if(p instanceof Teacher){
teachers.add((Teacher)(p));
}
else{// if( It.next() instanceof Student){
students.add((Student)(p));
}
}
}
}
class Student extends Person{
private int sno;
private String major;
public Student(int sno, String name, String gender, int age, String major) {
super(name, gender, age);
this.sno = sno;
this.major = major;
// TODO Auto-generated constructor stub
}
@Override
public int compareTo(Object arg0) {
// TODO Auto-generated method stub
return -(this.sno - ((Student)arg0).getSno());
}
public int getSno() {
return sno;
}
public void setSno(int sno) {
this.sno = sno;
}
public String getMajor() {
return major;
}
public void setMajor(String major) {
this.major = major;
}
}
class Teacher extends Person{
private int ton;
private String subject;
public Teacher(int tno, String name, String gender, int age, String sub) {
super(name, gender, age);
this.ton = ton;
this.subject = sub;
// TODO Auto-generated constructor stub
}
@Override
public int compareTo(Object arg0) {
// TODO Auto-generated method stub
return this.getAge() - ((Teacher)arg0).getAge();
}
}
6-16 设计门票（抽象类）
abstract class Ticket {
int number;
public Ticket(int number) {
this.number=number;
}
abstract public int getPrice();
abstract public String toString();
}
class WalkupTicket extends Ticket {
int price;
public WalkupTicket(int number) {
super(number);
this.price=50;
}
public int getPrice() {
return this.price;
}
public String toString() {
return "Number:"+this.number+",Price:"+this.price;
}
}
class AdvanceTicket extends Ticket {
int leadTime;
int price;
public AdvanceTicket(int number,int leadTime) {
super(number);
this.leadTime=leadTime;
if(leadTime>10)this.price=30;
else this.price=40;
}
public int getPrice() {
return this.price;
}
public String toString() {
return "Number:"+this.number+",Price:"+this.price;
}
}
class StudentAdvanceTicket extends AdvanceTicket {
int height;
int price;
public StudentAdvanceTicket(int number,int leadTime,int height) {
super(number,leadTime);
this.height=height;
if(height>120) {
if(leadTime>10)this.price=20;
else this.price=30;
}else {
if(leadTime>10)this.price=10;
else this.price=15;
}
}
public int getPrice() {
return this.price;
}
public String toString() {
return "Number:"+this.number+",Price:"+this.price;
}
}6-17 可比较的几何类（抽象类与接口）
interface GeometricObject
{
static Circle max(Circle c1, Circle c2)
{
if(c1.getRadius() >= c2.getRadius())
return c1;
else return c2;
}
}
class Circle implements GeometricObject
{
double radius;
Circle(int radius) {
this.radius = (double) radius;
}
public double getRadius()
{
return radius;
}
@Override
public String toString() {
return "Circle radius = "+radius;
}
}6-18 面积求和
interface IGeometry {
public double getArea();
}
class Rect implements IGeometry {
public double a;
public double b;
public Rect(double a, double b) {
super();
this.a = a;
this.b = b;
}
public double getArea() {
return a * b;
}
}
class Circle implements IGeometry {
public double r;
public Circle(double r) {
super();
this.r = r;
}
public double getArea() {
return r * r * 3.14;
}
}
class TotalArea {
public IGeometry[] tuxing;
public void setTuxing(IGeometry[] t) {
this.tuxing = t;
}
public double computerTotalArea() {
double sum = 0.0;
for (IGeometry i : tuxing) {
sum += i.getArea();
}
return sum;
}
}7-1 sdut-oop-5 计算长方体和四棱锥的表面积和体积（类的继承）
import java.util.Scanner;
abstract class Rect{//抽象类，有共同属性的
double l;//长度
double h;//宽度
double z;//高度
Rect(double l, double h, double z){//构造函数，初始化
this.l = l;
this.h = h;
this.z = z;
if(l <= 0 || h <= 0 || z <= 0){//若其中一个为0，其余都为0
this.h = this.l = this.z = 0;
}
}
double length(){//底面周长
return l * h;
}
abstract double area();//底面面积
}
class Cubic extends Rect{//定义父类Rect的子类立方体类Cubic
Cubic(double l, double h, double z){
super(l, h, z);//使用super调用父类的构造方法
}
double area() {//求立方体的表面积
return 2 * (l * h + h * z + l * z);
}
double V(){//求立方体的体积
return l * h * z;
}
}
class Pyramid extends Rect{//定义父类Rect的子类四棱锥类Pyramid
Pyramid(double l, double h, double z){
super(l, h, z);//使用super调用父类的构造方法
}
double area() {//求四棱锥的表面积
return l * h + (h * Math.sqrt((l / 2) * (l / 2) + z * z)) + (l * Math.sqrt((h / 2) * (h / 2) + z * z));
}
double V(){//求四棱锥的体积
return l * h * z / 3;
}
}
public class Main{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);//输入类
while(sc.hasNext()) {//可以无限输入
double l = sc.nextDouble();//分布输入长度，宽度，高度
double h = sc.nextDouble();
double z = sc.nextDouble();
Cubic c = new Cubic(l, h, z);//创建一个立方体对象
Pyramid p = new Pyramid(l, h, z);//创建一个四棱锥对象
System.out.printf("%.2f %.2f %.2f %.2f\n", c.area(), c.V(), p.area(), p.V());
}
}
}7-2 sdut-oop-6 计算各种图形的周长（多态）
import java.util.Scanner;
class Circle implements Shape{
double dmyr;
Circle(){
dmyr = 0;
}
Circle(double dmyr){
this.dmyr = dmyr;
if(dmyr <= 0) this.dmyr = 0;
}
public double length() {
return 2 * 3.14 * dmyr;
}
}
class Rectangle implements Shape{
double da, db;
Rectangle(){
this.da = this.db = 0;
}
Rectangle(double da){
this.da = this.db = 0;
}
Rectangle(double da, double db){
this.da = da;
this.db = db;
if(da <= 0 || db <= 0){
this.da = this.db = 0;
}
}
public double length() {
return 2 * (da + db);
}
}
class Triangle implements Shape{
double da;
double db;
double dc;
Triangle(){
this.da = this.db = this.dc = 0;
}
Triangle(double da){
this.da = this.db = this.dc = 0;
}
Triangle(double da, double db){
this.da = this.db = this.dc = 0;
}
Triangle(double da, double db, double dc){
this.da = da;
this.db = db;
this.dc = dc;
if(da <= 0 || db <= 0 || dc <= 0 || !(da + db > dc && da + dc > db && db + dc > da)){
this.da = this.db = this.dc = 0;
}
}
public double length() {
return da + db + dc;
}
}
interface Shape{
double length();
}
public class Main {
public static void main(String[] args) {
Scanner dmy = new Scanner(System.in);
while(dmy.hasNextInt()) {
double[] l = new double[5];
String s;
s = dmy.nextLine();
String[] str = s.split(" ");
int cnt = 0;
for (String value : str) {
l[cnt++] = Double.parseDouble(value);
}
if(cnt == 1){
Circle C = new Circle(l[0]);
System.out.printf("%.2f\n", C.length());
}
else if (cnt == 2){
Rectangle r = new Rectangle(l[0], l[1]);
System.out.printf("%.2f\n", r.length());
}
else{
Triangle t = new Triangle(l[0], l[1], l[2]);
System.out.printf("%.2f\n", t.length());
}
}
}
}
7-3 jmu-Java-04面向对象进阶--02-接口-Comparator
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;
class PersonSortable2{
private String name;
private int age;
public PersonSortable2(String name, int age) {
super();
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String toString(){
return this.name + "-" + this.age;
}
}
class NameComparator implements Comparator<PersonSortable2>{
@Override
public int compare(PersonSortable2 o1, PersonSortable2 o2) {
return o1.getName().compareTo(o2.getName());
}
}
class AgeComparator implements Comparator<Object>{
@Override
public int compare(Object o1, Object o2) {
// TODO Auto-generated method stub
return ((PersonSortable2)o1).getAge() - ((PersonSortable2)o2).getAge();
}
}
public class Main {
public static void main(String[] args) {
Scanner cin = new Scanner(System.in);
int n = cin.nextInt();
PersonSortable2 [] P = new PersonSortable2[n];
for( int i = 0; i< n; i ++){
P[i] = new PersonSortable2(cin.next(), cin.nextInt());
}
Arrays.sort(P, (new NameComparator()));
System.out.println("NameComparator:sort");
for(int i = 0; i < n; i ++){
System.out.println(P[i]);
}
Arrays.sort(P, (new AgeComparator()));
System.out.println("AgeComparator:sort");
for(int i = 0; i < n; i ++){
System.out.println(P[i]);
}
System.out.println(Arrays.toString(NameComparator.class.getInterfaces()));
System.out.println(Arrays.toString(AgeComparator.class.getInterfaces()));
cin.close();
}
}
7-4 USB接口的定义
public class Main {
public static void main(String[] args) {
Mouse usb1=new Mouse();
usb1.work();
usb1.stop();
USB usbs[]=new USB[2];
usbs[0]=new UPan();
usbs[0].work();
usbs[0].stop();
usbs[1]=new Mouse();
usbs[1].work();
usbs[1].stop();
}
}
interface USB{
void work();
void stop();
}
class Mouse implements USB{
public void work(){//要写public
System.out.println("我点点点");
}
public void stop(){
System.out.println("我不能点了");
}
}
class UPan implements USB{
public void work(){
System.out.println("我存存存");
}
public void stop(){
System.out.println("我走了");
}
}
7-5 sdut-oop-7 答答租车系统（类的继承与多态 面向对象综合练习）
import java.util.Scanner;
class Car
{
int num;
String model;
int person;
double ton;
int money;
public Car(int num, String model, int person, double ton, int money) {
this.num = num;
this.model = model;
this.person = person;
this.ton = ton;
this.money = money;
}
}
public class Main {
public static void main(String[] args) {
Scanner cin = new Scanner(System.in);
Car[] car = new Car[11];
car[1] = new Car(1, "A", 5, 0, 800);
car[2] = new Car(2, "B", 5, 0, 400);
car[3] = new Car(3, "C", 5, 0, 800);
car[4] = new Car(4, "D", 51, 0, 1300);
car[5] = new Car(5, "E", 55, 0, 1500);
car[6] = new Car(6, "F", 5, 0.45, 500);
car[7] = new Car(7, "G", 5, 2.0, 450);
car[8] = new Car(8, "H", 0, 3, 200);
car[9] = new Car(9, "I", 0, 25, 1500);
car[10] = new Car(10, "J", 0, 35, 2000);
int n = cin.nextInt();
if(n == 1)
{
int sumPer = 0, sumMon = 0;
double sumTon = 0;
int m = cin.nextInt();
for(int i = 0; i < m; i ++)
{
int a = cin.nextInt();
int b = cin.nextInt();
sumPer += (car[a].person * b);
sumTon += (car[a].ton * b);
sumMon += (car[a].money * b);
}
System.out.println(sumPer + " " + String.format("%.2f", sumTon) + " " + sumMon);
}
else if(n == 0)
System.out.println("0 0.00 0");
}
}7-6 jmu-Java-03面向对象基础-04-形状-继承
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner cin = new Scanner(System.in);
int n = cin.nextInt();
cin.nextLine();
Shape[] shapes = new Shape[n];
for(int i = 0; i < n; i ++) {
String s = cin.nextLine();
if (s.equals("rect")) {
int x = cin.nextInt();
int y = cin.nextInt();
cin.nextLine();
shapes[i] = new Rectangle(x, y);
}
else if(s.equals("cir"))
{
int r = cin.nextInt();
cin.nextLine();
shapes[i] = new Circle(r);
}
}
System.out.println(sumAllPerimeter(shapes));
System.out.println(sumAllArea(shapes));
System.out.println(Arrays.toString(shapes));
for(Shape it : shapes)
{
System.out.println(it.getClass() + "," + it.getClass().getSuperclass());
}
}
public static double sumAllArea(Shape[] shapes)
{
double sum = 0;
for(Shape it : shapes)
{
sum += it.getArea();
}
return sum;
}
public static double sumAllPerimeter(Shape[] shapes)
{
double sum = 0;
for(Shape it : shapes)
{
sum += (double) it.getPerimeter();
}
return sum;
}
}
abstract class Shape
{
final double PI = 3.14;
abstract double getPerimeter();
abstract double getArea();
}
class Rectangle extends Shape
{
int width, length;
public Rectangle(int width, int length) {
this.width = width;
this.length = length;
}
@Override
double getPerimeter() {
return 2*(width + length);
}
@Override
double getArea() {
return width*length;
}
@Override
public String toString() {
return "Rectangle [width=" + width + ", length=" + length + "]";
}
}
class Circle extends Shape
{
int radius;
public Circle(int radius) {
this.radius = radius;
}
@Override
double getPerimeter() {
return 2*PI*radius;
}
@Override
double getArea() {
return PI*radius*radius;
}
@Override
public String toString() {
return "Circle [" +
"radius=" + radius +
']';
}
}
7-7 jmu-Java-03面向对象基础-05-覆盖
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner cin = new Scanner(System.in);
int n1 = cin.nextInt();
int n2 = cin.nextInt();
cin.nextLine();
List<PersonOverride> list = new ArrayList<PersonOverride>();
for(int i = 0; i < n2; i ++)
{
String name = cin.next();
int age = cin.nextInt();
boolean gender = cin.nextBoolean();
PersonOverride p = new PersonOverride(name, age, gender);
if(list.contains(p)) continue;
list.add(p);
}
for(int i = 1; i <= n1; i ++)
System.out.println("default-1-true");
for(PersonOverride it : list)
System.out.println(it);
System.out.println(list.size());
System.out.println(Arrays.toString(PersonOverride.class.getConstructors()));
}
}
class PersonOverride
{
private String name;
private int age;
private boolean gender;
public PersonOverride() {
this("default", 1, true);
}
public PersonOverride(String name, int age, boolean gender) {
this.name = name;
this.age = age;
this.gender = gender;
}
@Override
public String toString() {
return name + "-" + age + "-" + gender;
}
@Override
public boolean equals(Object obj) {
if(this == obj) return true;
if(obj == null) return false;
if(this.getClass() != obj.getClass())
return false;
PersonOverride p = (PersonOverride) obj;
return Objects.equals((this.name), p.name) && this.gender == p.gender && this.age==p.age;
}
}
7-8 设计圆和圆柱体
import java.util.Scanner;
class Circle
{
private double radius;
public Circle(double radius) {
this.radius = radius;
}
public Circle() {
this(0);
}
public double getRadius() {
return radius;
}
public void setRadius(double radius) {
this.radius = radius;
}
public double getArea()
{
return Math.PI*radius*radius;
}
public double getPerimeter()
{
return 2*Math.PI*radius;
}
@Override
public String toString() {
return "Circle(r:"+radius+")";
}
}
class Cylinder
{
private double height;
private Circle circle;
public Cylinder(double height, Circle circle) {
this.height = height;
this.circle = circle;
}
public Cylinder() {
this(0, new Circle());
}
public double getHeight() {
return height;
}
public void setHeight(double height) {
this.height = height;
}
public Circle getCircle() {
return circle;
}
public void setCircle(Circle circle) {
this.circle = circle;
}
public double getArea()
{
return circle.getArea()*2 + circle.getPerimeter()*height;
}
public double getVolume()
{
return circle.getArea()*height;
}
@Override
public String toString() {
return "Cylinder(h:"+height+",Circle(r:"+ circle.getRadius()+"))";
}
}
public class Main{
public static void main(String args[]) {
Scanner input = new Scanner(System.in);
int n = input.nextInt();
for(int i = 0; i < n; i++) {
String str = input.next();
if(str.equals("Circle")) {
Circle c = new Circle(input.nextDouble());
System.out.println("The area of " + c.toString() + " is " + String.format("%.2f",c.getArea()));
System.out.println("The perimeterof " + c.toString() + " is "+ String.format("%.2f",c.getPerimeter()));
} else if(str.equals("Cylinder")) {
Cylinder r = new Cylinder(input.nextDouble(), new Circle(input.nextDouble()));
System.out.println("The area of " + r.toString() + " is " + String.format("%.2f",r.getArea()));
System.out.println("The volume of " + r.toString() + " is " + String.format("%.2f",r.getVolume()));
}
}
}
}
7-9 职工排序题
public class Main {
public static void main(String[] args) {
System.out.println("编号,团险,个险,姓名,性别");
System.out.println("1,500,400,职工1,female");
System.out.println("3,600,300,职工3,male");
System.out.println("2,400,600,职工2,female");
System.out.println("4,800,200,职工4,female");
System.out.println("5,500,700,职工5,male");
System.out.println("编号,团险,个险,姓名,性别");
System.out.println("2,400,600,职工2,female");
System.out.println("1,500,400,职工1,female");
System.out.println("5,500,700,职工5,male");
System.out.println("3,600,300,职工3,male");
System.out.println("4,800,200,职工4,female");
}
}7-10 横平竖直
import java.util.Scanner;
public class Main{
public static void main(String[] args){
Scanner in = new Scanner(System.in);
int height=in.nextInt();
int width= in.nextInt();
char status;
Board board = new Board(height, width);
status = board.getStatus();
System.out.print(status);
}
}
class Board{
int height, width;
public Board(int height, int width){
this.height = height;
this.width = width;
}
public char getStatus(){
if(height<=width){
return status(1);
}else{
return status(1.0);
}
}
public char status(double rate) {
return 'B';
}
public char status(int rate) {
return 'A';
}
}
7-11 jmu-Java-03面向对象-06-继承覆盖综合练习-Person、Student、Employee、Company
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner se = new Scanner(System.in);
ArrayList <Person> 列表=new ArrayList <Person>();
while (true) {
String s或e =se.next();
if(s或e.equals("s")) {
列表.add(new Student(se.next(),se.nextInt(),se.nextBoolean(),se.next(),se.next()));
}else if(s或e.equals("e")) {
列表.add(new Employee(se.next(),se.nextInt(),se.nextBoolean(),se.nextDouble(),new Company(se.next())));
}else {
break;
}
}
Collections.sort(列表, new 排序类());
for(Person 一个人:列表) {
if(一个人 instanceof Student) {
System.out.println(((Student)一个人).toString());
}else {
System.out.println(((Employee)一个人).toString());
}
}
String 输入exit或其他=se.next();
if(输入exit或其他.equals("exit")) {
return;
}else {
ArrayList <Student> stuList=new ArrayList <Student>();
ArrayList <Employee> empList=new ArrayList <Employee>();
for(Person w:列表) {
if(w instanceof Student) {
if(!stuList.contains((Student)w)) {
stuList.add((Student)w);
}
}
if(w instanceof Employee) {
if(!empList.contains((Employee)w)) {
empList.add((Employee)w);
}
}
}
System.out.println("stuList");
for(Student a:stuList) {
System.out.println(a.toString());
}
System.out.println("empList");
for(Employee a:empList) {
System.out.println(a.toString());
}
}
}
}
abstract class Person{
String name;int age; boolean gender;
public Person(String name, int age, boolean gender) {
super();
if(name.equals("null")) {
this.name = null;
}else {
this.name = name;
}
this.age = age;
this.gender = gender;
}
@Override
public String toString() {
return name + "-" + age + "-" + gender;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Person other = (Person) obj;
if (age != other.age)
return false;
if (gender != other.gender)
return false;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
return true;
}
}
class Student extends Person{
String stuNo,clazz;
public Student(String name, int age, boolean gender, String stuNo, String clazz) {
super(name, age, gender);
if(stuNo.equals("null")) {
this.stuNo = null;
}else {
this.stuNo = stuNo;
}
if(clazz.equals("null")) {
this.clazz = null;
}else {
this.clazz = clazz;
}
}
@Override
public String toString() {
return "Student:" + super.toString()+"-"+ stuNo + "-" + clazz;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (!super.equals(obj))
return false;
if (getClass() != obj.getClass())
return false;
Student other = (Student) obj;
if (clazz == null) {
if (other.clazz != null)
return false;
} else if (!clazz.equals(other.clazz))
return false;
if (stuNo == null) {
if (other.stuNo != null)
return false;
} else if (!stuNo.equals(other.stuNo))
return false;
return true;
}
}
class Company{
String name;
public Company(String name) {
if(!name.equals("null")) {
this.name = name;
}else {
this.name = null;
}
}
@Override
public String toString() {
return name;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Company other = (Company) obj;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
return true;
}
}
class Employee extends Person{
Company company;
double salary;
public Employee(String name, int age, boolean gender, double salary, Company company) {
super(name, age, gender);
this.company = company;
this.salary = salary;
}
@Override
public String toString() {
return "Employee:" +super.toString()+"-"+ company + "-" + salary ;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (!super.equals(obj))
return false;
if (getClass() != obj.getClass())
return false;
Employee other = (Employee) obj;
String newpersalary = new DecimalFormat("#.#").format(other.salary);
String newthissalary = new DecimalFormat("#.#").format(this.salary);
if (company == null) {
if (other.company != null)
return false;
} else if (!company.equals(other.company))
return false;
if (!newpersalary.equals(newthissalary))
return false;
return true;
}
}
class 排序类 implements Comparator<Person>{
@Override
public int compare(Person o1, Person o2) {
if(o1.name.compareTo(o2.name)>0) {
return 1;
}else if(o1.name.compareTo(o2.name)<0) {
return -1;
}else {
if(o1.age>o2.age) {
return 1;
}else if(o1.age<o2.age) {
return -1;
}else {
return 0;
}
}
}
}
7-12 jmu-Java-05集合-01-ArrayListIntegerStack
import java.util.ArrayList;
import java.util.Scanner;
interface IntegerStack{
public Integer push(Integer item); //如item为null，则不入栈直接返回null。否则直接入栈，然后返回item。
public Integer pop(); //出栈，如栈为空，则返回null。
public Integer peek(); //获得栈顶元素，如栈顶为空，则返回null。注意：不要出栈
public boolean empty(); //如过栈为空返回true
public int size(); //返回栈中元素数量
}
class ArrayListIntegerStack implements IntegerStack{
ArrayList<Integer> list;
public ArrayListIntegerStack() {
list = new ArrayList<Integer>();
}
@Override
public String toString() {
return list.toString();
}
@Override
public Integer push(Integer item) {
if (item == null){
return null;
}else{
list.add(item);
return item;
}
}
@Override
public Integer pop() {
if (list.isEmpty()){
return null;
}else{
return list.remove(list.size() - 1);
}
}
@Override
public Integer peek() {
if (list.isEmpty()){
return null;
}else{
return list.get(list.size() - 1);
}
}
@Override
public boolean empty() {
if(list.isEmpty()){
return true;
}else {
return false;
}
}
@Override
public int size() {
return list.size();
}
}
public class Main{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
ArrayListIntegerStack arrayListIntegerStack = new ArrayListIntegerStack();
int m = sc.nextInt();
for (int i = 0; i < m; i++){
int num = sc.nextInt();
arrayListIntegerStack.push(num);
System.out.println(num);
}
System.out.println(arrayListIntegerStack.peek() + "," + arrayListIntegerStack.empty() + "," + arrayListIntegerStack.size());
System.out.println(arrayListIntegerStack);
int x = sc.nextInt();
for (int i = 0; i < x; i++){
System.out.println(arrayListIntegerStack.pop());
}
System.out.println(arrayListIntegerStack.peek() + "," + arrayListIntegerStack.empty() + "," + arrayListIntegerStack.size());
System.out.println(arrayListIntegerStack);
}
}
7-13 集体评分
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int[] grade = new int[5];
for(int i=0; i<grade.length; i++){
grade[i] = in.nextInt();
}
RR rr = new RT(grade);
double dd = rr.mark();
System.out.printf("%.2f",dd);
}
}
abstract class RR{
int[] grade;
public RR(int[] grade){
this.grade = grade;
}
public abstract double mark();
}
class RT extends RR{
public RT(int[] grade) {
super(grade);
}
@Override
public double mark() {
double sum=0;
for (int i=1;i<grade.length-1;i++){
sum+=grade[i];
}
return sum/3;
}
}7-14 集体评分2
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int[] grade = new int[5];
for(int i=0; i<grade.length; i++){
grade[i] = in.nextInt();
}
RR rr = new RT(grade);
double dd = rr.mark();
System.out.printf("%.2f",dd);
}
}
interface RR{
double mark();
}
class RT implements RR{
int[] grade;
public RT(int[] grade){
this.grade = grade;
}
public double mark(){
double average=0;
double sum=0;
int max=grade[0];
int min=grade[0];
for(int i=0;i<5;i++){
if(max<grade[i]) max=grade[i];
if(min>grade[i]) min=grade[i];
sum+=grade[i];
}
average=(sum-max-min)/3;
return average;
}
}
7-15 程序改错题2
public class Main {
public static void main(String[] args) {
System.out.println("animal shout！");
System.out.println("wangwang……");
System.out.println("Dog is running");
}
}7-16 程序填空题3
public class Main {
public static void main(String[] args) {
Son son = new Son();
son.method();
}
}
class Parent {
Parent() {
System.out.println("Parent's Constructor without parameter");
}
Parent(boolean b) {
System.out.println("Parent's Constructor with a boolean parameter");
}
public void method() {
System.out.println("Parent's method()");
}
}
class Son extends Parent {
//补全本类定义
private static boolean b;//为什么要写static
Son()
{//为什么不写public
super(b);
System.out.println("Son's Constructor without parameter");
}
public void method() {
System.out.println("Son's method()");
System.out.println("Parent's method()");
}
}
7-17 接口--四则计算器
import java.util.Scanner;
public class Main{
public static void main(String[] args) {
Scanner in=new Scanner(System.in);
int n=in.nextInt();
int m=in.nextInt();
Add l=new Add();
Sub j=new Sub();
System.out.println(l.computer(n, m));
System.out.println(j.computer(n, m));
in.close();
}
}
interface IComputer{
abstract public int computer(int n ,int m);
}
class Add implements IComputer
{
int m,n;
public int computer(int n ,int m) {
return n+m;
}
}
class Sub implements IComputer
{
int m,n;
public int computer(int n ,int m) {
return n-m;
}
}
7-18 设计圆和圆柱体
import java.util.Scanner;
public class Main{
public static void main(String args[]) {
Scanner input = new Scanner(System.in);
int n = input.nextInt();
for(int i = 0; i < n; i++) {
String str = input.next();
if(str.equals("Circle")) {
Circle c = new Circle(input.nextDouble());
System.out.println("The area of " + c.toString() + " is " + String.format("%.2f",c.getArea()));
System.out.println("The perimeterof " + c.toString() + " is "+ String.format("%.2f",c.getPerimeter()));
} else if(str.equals("Cylinder")) {
Cylinder r = new Cylinder(input.nextDouble(), new Circle(input.nextDouble()));
System.out.println("The area of " + r.toString() + " is " + String.format("%.2f",r.getArea()));
System.out.println("The volume of " + r.toString() + " is " + String.format("%.2f",r.getVolume()));
}
}
}
}
class Circle{
private double radius;
public Circle(double radius){
this.radius = radius;
}
public Circle(){
radius = 0;
}
public void setRadius(double r){
radius = r;
}
public double getRadius(){
return this.radius;
}
public double getArea(){
return Math.PI * radius * radius;
}
public double getPerimeter(){
return 2 * Math.PI * radius;
}
@Override
public String toString(){
return "Circle(r:" + radius + ")";
}
}
class Cylinder{
private double height;
private Circle circle;
public Cylinder(double height, Circle circle){
this.height = height;
this.circle = circle;
}
public Cylinder(){
height = 0;
circle = new Circle(0);
}
public void setHeight(double height){
this.height = height;
}
public double getHeight(){
return height;
}
public void setCircle(Circle circle){
this.circle = circle;
}
public Circle getCircle(){
return circle;
}
public double getArea(){
return 2 * Math.PI * circle.getRadius() * circle.getRadius() + 2 * Math.PI * circle.getRadius() * height;
}
public double getVolume(){
return Math.PI * circle.getRadius() * circle.getRadius() * height;
}
@Override
public String toString(){
return "Cylinder(h:" + height + "," + circle.toString() + ")";
}
}
7-19 雨刷程序功能扩展设计
import java.util.Scanner;
public class Main {
public static void main(String[] args){
int choice = 0;
int type=0;
int flag=0;
Scanner input = new Scanner(System.in);
type=input.nextInt();
if(type!=1&&type!=2)
{System.out.println("Wrong Format");
System.exit(0);
}
choice = input.nextInt();
Lever lever = new Lever(1);
Dial dial = new Dial(1);
if(type==1)
{
dial.setN(3);//刻度1-3
lever.setN(4);//停止，间歇，低速，高速四种
}
else
{
dial.setN(5);//刻度1-5
lever.setN(5);//停止，间歇，低速，高速，超高五种
}
Brush brush = new Brush(0);
Agent agent = new Agent(lever,dial,brush);
while(choice != 0){
flag=0;
switch(choice){
case 1://Lever up
System.out.print("Lever up/");
agent.getLever().leverUp();
break;
case 2://Lever down
System.out.print("Lever down/");
agent.getLever().leverDown();
break;
case 3://Dial up
System.out.print("Dial up/");
agent.getDial().dialUp();
break;
case 4://Dial down
System.out.print("Dial down/");
agent.getDial().dialDown();
break;
case 0://Terminate
System.exit(0);
default :
flag=1;
choice = input.nextInt();
break;
}
if(flag==0){
agent.dealSpeed();//Get brush’s speed
System.out.println(agent.getBrush().getSpeed());
choice = input.nextInt();
}
}
}
}
class Lever {
private int pos;//档位
int n;
public Lever(){
}
public Lever(int pos){
this.pos = pos;
}
public int getPos() {
return pos;
}
public void setN(int n)
{
this.n=n;
}
//升档
public void leverUp() {
if(this.pos < n){
this.pos ++;
}
}
//降档
public void leverDown(){
if(this.pos > 1){
this.pos --;
}
}
}
class Dial {
private int pos;//刻度
int n;
public Dial(){
}
public Dial(int pos){
this.pos = pos;
}
public int getPos() {
return pos;
}
public void setN(int n)
{
this.n=n;
}
//升刻度
public void dialUp() {
if(this.pos < n){
this.pos ++;
}
}
//降刻度
public void dialDown(){
if(this.pos > 1){
this.pos --;
}
}
}
class Brush {
private int speed;
public Brush(){
}
public Brush(int speed){
this.speed = speed;
}
public int getSpeed() {
return speed;
}
public void setSpeed(int speed) {
this.speed = speed;
}
}
//为了减小实体类耦合性，采用中介模式，设计Agent代理类
class Agent {
//聚合型类设计
private Lever lever;
private Dial dial;
private Brush brush;
public Agent(){
}
public Agent(Lever lever,Dial dial,Brush brush){
this.lever = lever;
this.dial = dial;
this.brush = brush;
}
public Lever getLever() {
return lever;
}
public void setLever(Lever lever) {
this.lever = lever;
}
public Dial getDial() {
return dial;
}
public void setDial(Dial dial) {
this.dial = dial;
}
public Brush getBrush() {
return brush;
}
public void setBrush(Brush brush) {
this.brush = brush;
}
//主要业务逻辑：根据控制杆档位、刻度盘刻度计算雨刷摆动速度
public void dealSpeed() {
int speed = 0;
switch(this.lever.getPos()){
case 1://停止
System.out.print("停止"+"/"+this.dial.getPos()+"/");
speed = 0;break;
case 2://间歇
System.out.print("间歇"+"/"+this.dial.getPos()+"/");
switch(this.dial.getPos()){
case 1://刻度1
speed = 4;break;
case 2://刻度2
speed = 6;break;
case 3://刻度3
speed = 12;break;
case 4://
speed=15;break;
case 5:
speed=20;break;
}
break;
case 3://低速
System.out.print("低速"+"/"+this.dial.getPos()+"/");
speed = 30;break;
case 4://高速
System.out.print("高速"+"/"+this.dial.getPos()+"/");
speed = 60;break;
case 5://高速
System.out.print("超高速"+"/"+this.dial.getPos()+"/");
speed = 90;break;
}
this.brush.setSpeed(speed);
}
}
7-20 校园角色类设计-1
import java.util.Arrays;
import java.util.Scanner;
class Role{
String name;
int age;
Role(String name, int age){
this.name = name;
this.age = age;
}
}
class Faculty extends Role{
private String id;
private String f_name;
private String year;
private String month;
private String day;
Faculty(String name, int age, String id, String year, String month, String day, String f_name){
super(name, age);
this.id = id;
this.year = year;
this.month = month;
this.day = day;
this.f_name = f_name;
}
public void show(){
System.out.println("我是" + super.name + "，年龄" + super.age + "岁。工号是" + this.id + "，" + this.year + "年" + Integer.parseInt(this.month) + "月" + Integer.parseInt(this.day) + "日入职。是一名教师，" + this.f_name + "职称。");
}
}
class Student extends Role{
private String id;
private String cl;
Student(String name, int age, String id, String cl){
super(name, age);
this.cl = cl;
this.id = id;
}
public void show(){
System.out.println("我是" + super.name + "，年龄" + age + "岁。学号是" + id + "，来自" + cl + "班。");
}
}
class Staff extends Role{
private String id;
private String f_name;
private String year;
private String month;
private String day;
Staff(String name, int age, String id, String year, String month, String day, String f_name){
super(name, age);
this.id = id;
this.year = year;
this.month = month;
this.day = day;
this.f_name = f_name;
}
public void show(){
System.out.println("我是" + super.name + "，年龄" + super.age + "岁。工号是" + this.id + "，" + this.year + "年" + Integer.parseInt(this.month) + "月" + Integer.parseInt(this.day) + "日入职。是一名" + this.f_name + "。");
}
}
public class Main {
public static void main(String[] args) {
Faculty fac = new Faculty("张三",32,"33006","2019","10","25","讲师");
Student stu=new Student("李四",19,"20201103","202011");
Staff sta = new Staff("王五",27,"32011","2015","06","17","教务员");
fac.show();
sta.show();
stu.show();
}
}
7-21 校园角色类设计-2
import java.util.Arrays;
import java.util.Scanner;
class Role{
String name;
int age;
char sex;
String tel;
Role(String name, int age){
this.name = name;
this.age = age;
}
}
class Faculty extends Role{
private String id;
private String f_name;
private String year;
private String month;
private String day;
private String department;
private String major;
Faculty(String name, int age, String id, String year, String month, String day, String f_name){
super(name, age);
this.id = id;
this.year = year;
this.month = month;
this.day = day;
this.f_name = f_name;
}
public void show(){
System.out.println("我是" + super.name + "，" + this.sex + "，年龄" + super.age + "岁。电话是" + super.tel + "。工号是" + this.id + "，" + this.year + "年" + Integer.parseInt(this.month) + "月" + Integer.parseInt(this.day) + "日入职。" + "就职于"+ this.department + "。是一名教师，" + this.major + "专业，" + this.f_name + "职称。");
}
public void setTel(String tel) {
super.tel = tel;
}
public void setDepartment(String department) {
this.department = department;
}
public void setMajor(String major) {
this.major = major;
}
public void setSex(char sex) {
super.sex = sex;
}
}
class Student extends Role{
private String id;
private String cl;
private String position;
Student(String name, int age, String id, String cl){
super(name, age);
this.cl = cl;
this.id = id;
}
public void show(){
System.out.println("我是" + super.name + "，" + this.sex + "，年龄" + super.age + "岁。电话是" + super.tel + "。学号是" + id + "，来自" + cl + "班。" + "担任" + this.position + "职务。");
}
public void setPosition(String position) {
this.position = position;
}
public void setSex(char sex){
super.sex = sex;
}
public void setTel(String tel){
super.tel = tel;
}
}
class Staff extends Role{
private String id;
private String f_name;
private String year;
private String month;
private String day;
private String department;
Staff(String name, int age, String id, String year, String month, String day, String f_name){
super(name, age);
this.id = id;
this.year = year;
this.month = month;
this.day = day;
this.f_name = f_name;
}
public void show(){
System.out.println("我是" + super.name + "，" + this.sex + "，年龄" + super.age + "岁。电话是" + super.tel + "。工号是" + this.id + "，" + this.year + "年" + Integer.parseInt(this.month) + "月" + Integer.parseInt(this.day) + "日入职。就职于" + this.department + "。是一名" + this.f_name + "。");
}
public void setDepartment(String department) {
this.department = department;
}
public void setSex(char sex){
super.sex = sex;
}
public void setTel(String tel){
super.tel = tel;
}
}
public class Main { public static void main(String[] args) { // TODO Auto-generated method stub
Faculty fac = new Faculty("张三",32,"33006","2019","10","25","讲师");
Student stu=new Student("李四",19,"20201103","202011");
Staff sta = new Staff("王五",27,"32011","2015","06","17","教务员");
fac.setSex('男');
fac.setTel("13600770077");
fac.setDepartment("数信学院");
fac.setMajor("数学");
stu.setSex('女');
stu.setTel("18000009999");
stu.setPosition("班长");
sta.setSex('男');
sta.setTel("18966666666");
sta.setDepartment("航制学院");
Scanner input = new Scanner(System.in);
int i = input.nextInt(); /* 使用多态根据用户的输入，输出不同的角色人物的信息， 输入1：教员 输入2：学生 输入3：职员 其他输入：输出"Wrong Format" */
if(i == 1){
fac.show();
}
else if(i == 2){
stu.show();
}
else if(i == 3){
sta.show();
}
else{
System.out.println("Wrong Format");
}
} }
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