实验5--抽象类和接口(共8页).doc

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1、精选优质文档-倾情为你奉上南昌大学实验报告学生姓名： 王维 学 号： 专业班级： 网工121班 实验类型： 验证 综合 设计 创新 实验日期： 实验成绩： 实验5 抽象类和接口一、实验目的1、掌握抽象类abstract的概念。2、掌握接口interface的概念。 3、掌握抽象类、接口的定义、实现与使用;4、理解接口和继承的混合使用二、实验内容 1、 课本p399 14.3题 和14.7题2、 将课本中的GeometricObject类改为接口，重新设计circle、rectangle类，实现相应的功能。三、实验要求1、通过上述程序的设计，清楚java中抽象类、接口的定义、实现与使用； 四、实

2、验环境1、PC微机；2、DOS操作系统或 Windows 操作系统；3、Sdk程序集成环境或Eclipse程序集成环境。五、实验步骤1、输入源程序；2、利用相关工具（Eclipse运行本程序）；3、查看实验结果，通过分析结果来掌握继承和多态的特征。六、测试数据 略七、源代码14.3题：Square类：public class Square extends GeometricObject implements Colorable private double length;public Square(double length)super();this.length=length;public

3、Square(double length,String color)super(color,true);this.length=length;public void howToColor() / TODO Auto-generated method stub System.out.println(Color all four sides);public void xx()Overridepublic double getArea() / TODO Auto-generated method stubreturn length*length;Overridepublic double getPe

4、rimeter() / TODO Auto-generated method stubreturn 4*length;Square测试类：public class TestSquare public static void main(String args) / TODO Auto-generated method stubGeometricObject objects = new GeometricObject5;objects0 = new Square(1);objects1 = new Square(1.5, red);objects2 = new Square(2.5);object

5、s3 = new Square(3.0, black);objects4 = new Square(5);for (int i = 0; i 5; i+) System.out.println(第 + i + 对象：);if (objectsi.isFilled() (Colorable) objectsi).howToColor(); elseSystem.out.println(不可着色);System.out.println(面积为： + objectsi.getArea();System.out.println(周长为： + objectsi.getPerimeter();14.7题O

6、ctagon类public class Octagon extends GeometricObject implements Comparable,Cloneable private double length;public Octagon(double length) this.length=length;Overridepublic double getArea() return (2+4/Math.sqrt(2)*length*length;Overridepublic double getPerimeter() return 0;public double getLength() re

7、turn length;public void setLength(double length) this.length = length;public int compareTo(Octagon o) if(this.lengtho.getLength()return 1;else if(this.lengtho.getLength()return -1;elsereturn 1;Overrideprotected Object clone() throws CloneNotSupportedException return super.clone();Octagon测试类：public c

8、lass TestOctagon public static void main(String args) / TODO Auto-generated method stubOctagon o = new Octagon(5);System.out.println(面积为：+o.getArea();System.out.println(周长为：+o.getPerimeter();接口GeometricObjectimport java.util.Date;public interface GeometricObject public String getColor();public void

9、setColor(String color);public boolean isFilled();public void setFilled(boolean filled);public Date getDateCreated();public String toString();public abstract double getArea();public abstract double getPerimeter();新的Circle类：import java.util.Date;public class Circle implements GeometricObject private S

10、tring color = white;private boolean filled;private java.util.Date dateCreated;private double radius;public Circle() dateCreated = new java.util.Date();public Circle(double radius) public String getColor() / TODO Auto-generated method stubreturn color;public void setColor(String color) / TODO Auto-ge

11、nerated method stubthis.color = color;public boolean isFilled() / TODO Auto-generated method stubreturn filled;public void setFilled(boolean filled) / TODO Auto-generated method stubthis.filled = filled;public Date getDateCreated() / TODO Auto-generated method stubreturn dateCreated;public double ge

12、tArea() / TODO Auto-generated method stubreturn radius * radius * Math.PI;public double getPerimeter() / TODO Auto-generated method stubreturn 2 * radius * Math.PI;public double getRadius() return radius;public void setRadius(double radius) this.radius = radius;新的Rectangle类：import java.util.Date;pub

13、lic class Rectangle implements GeometricObject private String color = white;private boolean filled;private java.util.Date dateCreated;private double width;private double height;public Rectangle() dateCreated = new java.util.Date();public Rectangle(double width, double height) this.width = width;this

14、.height = height;public String getColor() / TODO Auto-generated method stubreturn color;public void setColor(String color) / TODO Auto-generated method stubthis.color = color;public boolean isFilled() / TODO Auto-generated method stubreturn filled;public void setFilled(boolean filled) / TODO Auto-ge

15、nerated method stubthis.filled = filled;public Date getDateCreated() / TODO Auto-generated method stubreturn dateCreated;public double getArea() / TODO Auto-generated method stubreturn width * height;public double getPerimeter() / TODO Auto-generated method stubreturn 2 * (width + height);public dou

16、ble getWidth() return width;public void setWidth(double width) this.width = width;public double getHeight() return height;public void setHeight(double height) this.height = height;八、思考题1、分析Java中抽象类、接口异同点？相同点，都是对于类的一种抽象，不过接口的抽象程度更高。两者都含有未实现的方法，但是接口中的所有方法必须是公共的抽象实例方法，而抽象类无限制。两者都不能用new实例化，但是抽象类可以有构造方法，而接口不能有构造方法。抽象类的变量无限制，而接口所有变量必须是public static final。专心-专注-专业