java第十二周上机练习05/21

1.设计四个类，分别是：（知识点：抽象类及抽象方法）

（1）Shape表示图形类，有面积属性area、周长属性per，颜色属性color，有两个构造方法（一个是默认的、一个是为颜色赋值的），还有3个抽象方法，分别是：getArea计算面积、getPer计算周长、showAll输出所有信息，还有一个求颜色的方法getColor。

private double area;
private double per;
private String color;
 
public Shape() {
     
}
 
public Shape(String color) {
    this.color = color;
}
 
public abstract double getArea();
 
public abstract double getPer();
 
public abstract void showAll();
 
public void getColor() {
    System.out.println("颜色："+color);
}

（2）2个子类：

1）Rectangle表示矩形类，增加两个属性，Width表示长度、height表示宽度，重写getPer、getArea和showAll三个方法，另外又增加一个构造方法（一个是默认的、一个是为高度、宽度、颜色赋值的）。

    private double width;
    private double height;
    private String color;
     
     
    public Rectangless() {
         
    }
     
    public Rectangless(double width , double height , String color) {
        super(color);
        this.width = width;
        this.height =height;
    }
    @Override
    public double getArea() {
        // TODO Auto-generated method stub
        return width*height;
         
    }
 
    @Override
    public double getPer() {
        // TODO Auto-generated method stub
        return 2*(width+height);
 
    }
 
    @Override
    public void showAll() {
        // TODO Auto-generated method stub
        System.out.println("Rectangle:"+"长度为："+height+",宽度为："+width+",周长为："+getPer()+",面积为："+getArea());
         
         
    }
 
}

2）Circle表示圆类，增加1个属性，radius表示半径，重写getPer、getArea和showAll三个方法，另外又增加两个构造方法（为半径、颜色赋值的）。

private double radius;
private String color;
public Circle(String color) {
    super(color);
}
public Circle(double radius) {
    this.radius = radius;
}
 
@Override
public double getArea() {
    // TODO Auto-generated method stub
    return 3.14*(radius*radius);
     
}
 
@Override
public double getPer() {
    // TODO Auto-generated method stub
    return 3.14*(2*radius);
}
 
@Override
public void showAll() {
    // TODO Auto-generated method stub
    System.out.println("Circle:"+"半径为："+radius+",周长为："+getPer()+",面积为："+getArea());
}

（3）一个测试类PolyDemo，在main方法中，声明创建每个子类的对象，并调用2个子类的showAll方法。

Rectangless R = new Rectangless(5 , 4 ,"black");
R.showAll();
R.getColor();
 
System.out.println("==========================");
 
Circle C = new Circle(3);
Circle C1 = new Circle("red");
C.showAll();
C1.getColor();

2.Cola公司的雇员分为以下若干类：(知识点：多态)

(1) ColaEmployee ：这是所有员工总的父类，属性：员工的姓名,员工的生日月份。

方法：getSalary(int month) 根据参数月份来确定工资，如果该月员工过生日，则公司会额外奖励100 元。

    private String name;
    private int birmonth;
 
    public void getSalary(int month) {
        System.out.println("month:"+month);
}

(2) SalariedEmployee ： ColaEmployee 的子类，拿固定工资的员工。

属性：月薪

private double monthsalary;
private int month;
 
public void salarySalariedEmployee(String name, int workmonth, int birmonth, double monthsalary) {
    if (workmonth == birmonth) {
        System.out.println("name:" + name + ",birmonth:" + birmonth + ",sumSalary:" + (monthsalary * workmonth + 100));
    } else {
        System.out.println("name:" + name + ",birmonth:" + birmonth + ",sumSalary:" + monthsalary * workmonth);
    }
}

(3) HourlyEmployee ：ColaEmployee 的子类，按小时拿工资的员工，每月工作超出160 小时的部分按照1.5 倍工资发放。

属性：每小时的工资、每月工作的小时数

private double hoursalary;
private int monthhour;
 
public void salaryHourlyEmployee(String name, int birmonth, int workmonth, double hoursalary, int monthhour) {
    if (monthhour > 160) {
        if (workmonth == birmonth) {
            double sumsalary = (monthhour * workmonth - 160) * hoursalary * 1.5 + 160 * hoursalary + 100;
            System.out.println("name:" + name + ",birmonth:" + birmonth + ",sumSalary:" + sumsalary);
        } else {
            double sumsalary = (monthhour * workmonth - 160) * hoursalary * 1.5 + 160 * hoursalary;
            System.out.println("name:" + name + ",birmonth:" + birmonth + ",sumSalary:" + sumsalary);
        }
    } else {
        if (workmonth == birmonth) {
            double sumsalary = monthhour * workmonth * hoursalary + 100;
            System.out.println("name:" + name + ",birmonth:" + birmonth + ",sumSalary:" + sumsalary);
        } else {
            double sumsalary = monthhour * workmonth * hoursalary;
            System.out.println("name:" + name + ",birmonth:" + birmonth + ",sumSalary:" + sumsalary);
        }
    }
}

(4) SalesEmployee ：ColaEmployee 的子类，销售人员，工资由月销售额和提成率决定。

属性：月销售额、提成率

private double monthsale;
private double rate;
 
public void salarySalesEmployee(String name, int birmonth, int workmonth, double monthsale, double rate) {
    if (workmonth == birmonth) {
        double sumsalary = (monthsale * workmonth) * rate + 100;
        System.out.println("name:" + name + ",birmonth:" + birmonth + ",sumSalary:" + sumsalary);
    } else {
        double sumsalary = (monthsale * workmonth) * rate;
        System.out.println("name:" + name + ",birmonth:" + birmonth + ",sumSalary:" + sumsalary);
    }
 
}

(5) 定义一个类Company，在该类中写一个方法，调用该方法可以打印出某月某个员工的工资数额，写一个测试类TestCompany,在main方法，把若干各种类型的员工放在一个ColaEmployee 数组里，并单元出数组中每个员工当月的工资。

public static void show(ColaEmployee ce) {
    if (ce instanceof SalariedEmployee) {
        SalariedEmployee se = (SalariedEmployee) ce;
        se.salarySalariedEmployee("张三", 6, 6, 6700);
    } else if (ce instanceof HourlyEmployee) {
        HourlyEmployee he = (HourlyEmployee) ce;
        he.salaryHourlyEmployee("李四", 5, 6, 15, 180);
    } else if (ce instanceof SalesEmployee) {
        SalesEmployee see = (SalesEmployee) ce;
        see.salarySalesEmployee("王五", 7, 5, 5200, 0.5);
    }
}

package homework;
 
public class TestCompany {
 
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Company C = new Company();
        SalariedEmployee se = new SalariedEmployee();
        C.show(se);
 
        System.out.println("======================================");
 
        HourlyEmployee he = new HourlyEmployee();
        C.show(he);
 
        System.out.println("======================================");
 
        SalesEmployee see = new SalesEmployee();
        C.show(see);
 
    }
 
}

3、利用接口实现动态的创建对象：（知识点：接口）

（1）创建4个类

1苹果

2香蕉

3葡萄

4园丁

（2）在三种水果的构造方法中打印一句话.

以苹果类为例

class apple

{

public apple()

{

System.out.println(“创建了一个苹果类的对象”);

}

（3）类图如下：

（4）要求从控制台输入一个字符串，根据字符串的值来判断创建三种水果中哪个类的对象。

package homework;

public class Apple implements Fruit{
	
	public Apple() {
		System.out.println("创建了一个苹果类的对象");
	}
}

package homework;

public class Banana implements Fruit{
	
	public Banana() {
		System.out.println("创建了一个香蕉类的对象");
	}
}

package homework;

public class Grape implements Fruit{
	
	public Grape() {
		System.out.println("创建了一个葡萄类的对象");
	}
}

package homework;

import java.util.Scanner;

public interface Fruit {
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		System.out.println("请输入水果名字：");
		String fruitName = sc.next();
		if(fruitName.equals("苹果")) {
			new Apple();
		}else if(fruitName.equals("香蕉")) {
			new Banana();
		}else if(fruitName.equals("葡萄")) {
			new Grape();
		}else {
			System.out.println("抱歉！ 暂无此类水果····");
		}
	}
	
}