java实验二.doc

信 息 工 程 学 院实验报告的内容与格式按任课教师的要求书写。 Java程序设计 实验/实习报告学院:班级:地信姓名:学号:2 成绩:A面向对象编程1、 实验/实习过程（一）实验目的掌握Java程序面向对象编程的基本架构，会运用面向对象的思想编写Java程序。（二）实验过程【实验题1】 完成如下程序，完成思考题基本要求 运行程序并观察运行结果。思考问题 试述程序中主要语句的作用运行结果：主要程序语句的作用已标注为注释：class CCircle / 类的声明 double pi; /申明成员变量 double radius;/申明成员变量 double getRadius() /创建方法 return radius;/返回 radius void setCircle(double r, double p) /创建方法 pi=p;/初始化数据成员 radius=r;/初始化数据成员 public class Ex2_1/类的声明 public static void main(String args)/主方法 CCircle cir1=new CCircle(); /创建对象 cir1.setCircle(2.0,3.1416);/调用对象 System.out.println(radius=+cir1.getRadius(); /输出结果 【实验题2】 设计一个用来描述汽车的类，使用类的静态成员变量来表示汽车的车主姓名、当前的速率和当前方向盘的转向角度，使用类的非静态成员方法来表示改变汽车的速率和停车两个操作。package zz1;public class Car String name; int speed; int jiaodu; public Car(String name,int speed,int jiaodu) =name; this.speed=speed; this.jiaodu=jiaodu; System.out.println(车主：+); System.out.println(车速为：+this.speed); System.out.println(方向盘角度：+this.jiaodu); void changename(String name) =name; System.out.println(当前车主为：+); void changespeed(int speed) this.speed=speed; System.out.println(当前速度为：+this.speed); void changejiaodu(int jiaodu) this.jiaodu=jiaodu; System.out.println(当前方向盘角度为：+this.jiaodu); void stop() this.speed =0; System.out.println(停车后，车速为：+this.speed); public static void main(String args) Car car=new Car(张震宇张三,0,0); car.changename(好友); car.changespeed(20); car.changejiaodu(30); car.stop(); 结果：【实验题3】 定义一个类MyProgram，包含两个属性：一个是private的整型属性data、一个是private的String类型的属性str，封装这两个属性的四个方法setData（）和getData（）、setStr( )和getStr（）；将这两个属性转变为字符串的方法是toStr（）。编写程序，使用MyProgram类，实现数据的访问和修改，并调用toStr（）方法显示该类的属性。基本要求 编写完整程序。思考问题 试述程序中各个方法的作用。代码如下：package zz1;public class Myprogram private int data;private String str;void setdata(int data)this.data=data;int getdata()return data;void setstr(String str)this.str=str;String getstr()return str;String toStr()String a=data+ ;a=str;return a;public static void main(String args)Myprogram m=new Myprogram();m.data=1000;m.str=jgfldjsglkdj;System.out.println(转换之前：+m.data);System.out.println(转换之后：+m.str);结果如下：思考问题 试述程序中各个方法的作用。setData（）和setStr()方法的作用是获得数据和资料，getData（）、和getStr（）作用为设置数据和资料。toStr()函数用来将其他类型转化为字符串类型。【实验题4】 定义一个类实现银行帐户的概念，包括的变量有帐号和存款余额，包括的方法有存款、取款、查询余额和”显示帐号”。定义主类，创建帐户类的对象，并完成相应操作。提示：关键代码如下：public int getleftmoney()return leftmoney;public void savemoney(double money)leftmoney+=money;public void getmoney(double money)if(money=leftmoney)leftmoney-=money;elseSystem.out.println(只能取：+leftmoney);bankaccount ba=new bankaccount(888123,1000);ba.savemoney(21000);System.out.println(存入21000元后余额为：+ba.getleftmoney();ba.getmoney(11500);System.out.println(11500元后余额为：+ba.getleftmoney();代码如下:package zz1;public class Bankaccount int acc;int leftmoney;Bankaccount(int acc,int leftmoney)this.acc=acc;this.leftmoney=leftmoney;public int getleftmoney()return leftmoney;public void savemoney(double money)leftmoney+=money;public void getmoney(double money)if(money 0) this.width=w; public double getWidth() return width; public void setLength (double h) if(length 0) this.length =h; public double getLength () return length; 代码如下：package zz1;public class Cuboid double rect,height; double width,length; Cuboid(double height) this.height=height; public void getBottomWidth(double width) if(width 0) this.width=width; public void setBottomWidth() System.out.println(底面宽是：+width); public void getBottomLength(double length) if(length 0) this.length =length; public void setBottomLength () System.out.println(底面长是：+length); public void getVolme() double V; V=width*length*height; System.out.println(柱形的体积是：+V); public static void main(String args) Cuboid cub=new Cuboid(20); cub.getBottomWidth(15); cub.getBottomLength(17); cub.setBottomWidth(); cub.setBottomLength(); cub.getVolme(); 结果如下：【实验题5】 有图形类的父类Shape，参照圆Circle类补充完整正方性Square和三角形Triangle类，并分析运行结果。class Shape void draw() void erase() class Circle extends Shape void draw() System.out.println(Circle.draw();void erase() System.out.println(Circle.erase();class Square extends Shape void draw() void erase() class Triangle extends Shape void draw() void erase() public class Shapes public static Shape randShape() switch(int)(Math.random() * 3) default: / To quiet the compiler case 0: return new Circle();case 1: return new Square();case 2: return new Triangle(); public static void main(String args) Shape s = new Shape3; / Fill up the array with shapes:for(int i = 0; i s.length; i+)si = randShape(); / Make polymorphic method calls:for(int i = 0; i s.length; i+)si.draw(); 补充完整的代码如下：package zz1;class Shape void draw() void erase() class Circle extends Shape void draw() System.out.println(Circle.draw();void erase() System.out.println(Circle.erase();class Square extends Shape void draw() System.out.println(Square.draw(); void erase() System.out.println(Square.erase();class Triangle extends Shape void draw() System.out.println(Triangle.erase(); void erase() System.out.println(Triangle.erase(); public class Shapes public static Shape randShape() switch(int)(Math.random() * 3) default: / To quiet the compilercase 0: return new Circle();case 1: return new Square();case 2: return new Triangle(); public static void main(String args) Shape s = new Shape3; / Fill up the array with shapes:for(int i = 0; i s.length; i+)si = randShape(); / Make polymorphic method calls:for(int i = 0; i s.length; i+)si.draw(); 运行结果：【实验题6】 有两个类：MobileManagement和Mobile，分别描述如图所示两部手机名称及价格，类MobileManagement在包.nwsuaf.jp.p3中，而Mobile在包.nwsuaf.jp.p3.data中。它们代码如下。运行MobileManagement.java，你应该看到如图所示结果。基本要求 在空白处填写相关代码并修改上面程序，使程序能够显示两部手机的价格和数量，运行结果如图所示。E365, 1780 RMB M330, 1450 RMB手机及价格图程序Mobile.java源代码：public class Mobile /* Holds the name of the mobile. */private String name;/* Holds the price of the mobile. */private float price;/* Creates a new mobile object. */public Mobile(String name, float price) = name;this.price = price;/* Gets the name of the mobile. */public String getName() return name;/* Gets the price of the mobile. */Public float getPrice() return price;程序MobileManagement.java源代码：import javax.swing.JOptionPane;public class MobileManagement /* Defines the entry point of the application. */public static void main(String args) / Creates two mobile phone objects.Mobile mobile1 = new Mobile(E365, 1780);Mobile mobile2 = new Mobile(M330, 1450);/ Displays the two mobile phones in a dialog box.JOptionPane.showMessageDialog(null, Mobile phones:nn+mobile1.getName()+n+mobile2.getName(); 实验结果如下截图：【实验题7】有四个类，主类Store在包.nwsuaf.jp.p4中，Mobile、Mp3Player、Product在包.nwsuaf.jp.p4.data中，Mobile、Mp3Player是Product的子类，Product和Store代码如下：Store.java源代码：package .nwsuaf.jp.p4;import java.util.Arrays;import javax.swing.JOptionPane;import .nwsuaf.jp.p4.data.Mobile;import .nwsuaf.jp.p4.data.Mp3Player;import .nwsuaf.jp.p4.data.Product;public class Store /* Defines the entry point of the application. */public static void main(String args) / Creates two mobile phone objects.Mobile mobile1 = new Mobile(China Mobile, E365,1780);Mobile mobile2 = new Mobile(China Mobile, M330,1450);Mp3Player player1 = new Mp3Player(Meizo X3, 256, 399);Mp3Player player2 = new Mp3Player(Meizo E5, 512, 580);Mp3Player player3 = new Mp3Player(Xlive XM MP3 Play,256, 930);Product products=mobile1,mobile2,player1,player2, player3;Arrays.sort(products);String text = ;for(int index = 0; index products.length; +index)text += productsindex.toString()+n;/ Displays the two mobile phones in a dialog box.JOptionPane.showMessageDialog(null,The productsare:nn+text+nThere are +Product.getCount()+ products.); Mp3Player的完整代码如下：package .nwsuaf.jp.p4.data;public class Mp3Player extends Product private int capacity;public Mp3Player(String name,int capacity,float price) super(name,price);this.capacity=capacity; public float getPrice() return price; public String name() return name; public