201771010109焦旭超《面向对象程序设计（java）》第十一周学习总结

 1、实验目的与要求

(1) 掌握Vetor、Stack、Hashtable三个类的用途及常用API；

(2) 了解java集合框架体系组成；

(3) 掌握ArrayList、LinkList两个类的用途及常用API。

(4) 了解HashSet类、TreeSet类的用途及常用API。

(5)了解HashMap、TreeMap两个类的用途及常用API；

(6) 结对编程（Pair programming）练习，体验程序开发中的两人合作。

2、实验内容和步骤

实验1： 导入第9章示例程序，测试程序并进行代码注释。

测试程序1：

l 使用JDK命令运行编辑、运行以下三个示例程序，结合运行结果理解程序；

掌握Vetor、Stack、Hashtable三个类的用途及常用API。

import java.util.Vector;

//示例程序1

class Cat {
    private int catNumber;

    Cat(int i) {
        catNumber = i;
    }

    void print() {
        System.out.println("Cat #" + catNumber);
    }
}
class Dog {
    private int dogNumber;

    Dog(int i) {
        dogNumber = i;
    }

    void print() {
        System.out.println("Dog #" + dogNumber);
    }
}
public class CatsAndDogs {
    public static void main(String[] args) {
        Vector cats = new Vector();//创建一个新的类
        for (int i = 0; i < 7; i++)
            cats.addElement(new Cat(i));
        cats.addElement(new Dog(7));
        for (int i = 0; i < cats.size(); i++)
        if(cats.elementAt(i)instanceof Cat)// instanceof运算符是用来指出对象是否是特定类的一个实例
        {    
            ((Cat) cats.elementAt(i)).print();
        }else {
            ((Dog) cats.elementAt(i)).print();
        }
    }
}

示例程序2：

import java.util.*;

public class Stacks //栈（先进后出）
{
    static String[] months = { "1", "2", "3", "4" };

    public static void main(String[] args) {
        Stack stk = new Stack();
        for (int i = 0; i < months.length; i++)
            stk.push(months[i]);//进栈
        System.out.println(stk);
        System.out.println("element 2=" + stk.elementAt(2));
        while (!stk.empty())
            System.out.println(stk.pop());//输出出栈元素
    }
}

示例程序3：

import java.util.*;

class Counter {
    int i = 1;//不加权限修饰符：friendly型

    public String toString() //把其他类型的数据转为字符串类型的数据
    {
        return Integer.toString(i);
    }
}

public class Statistics {
    public static void main(String[] args) {
        Hashtable ht = new Hashtable();
        for (int i = 0; i < 10000; i++) {
            Integer r = new Integer((int) (Math.random() * 20));//生成0到20(不包括20）的整型随机数
            if (ht.containsKey(r))//判断r是否是哈希表中一个元素的键值
                ((Counter) ht.get(r)).i++;//通过get方法获得其值
            else
                ht.put(r, new Counter());//ht不存在
        }
        System.out.println(ht);
    }
}

测试程序2：

使用JDK命令编辑运行ArrayListDemo和LinkedListDemo两个程序，结合程序运行结果理解程序；

ArrayListDemo：

import java.util.*;

public class ArrayListDemo//ArrayList使用了数组的实现
{
    public static void main(String[] argv) {
        ArrayList al = new ArrayList();
        //在ArrayList中添加大量元素
        al.add(new Integer(11));
        al.add(new Integer(12));
        al.add(new Integer(13));
        al.add(new String("hello"));//下标从0开始，添加4个元素
        // First print them out using a for loop.
        System.out.println("Retrieving by index:");
        for (int i = 0; i < al.size(); i++) {
            System.out.println("Element " + i + " = " + al.get(i));
        }
    }
}

import java.util.*;
public class LinkedListDemo {
    public static void main(String[] argv) {
        LinkedList l = new LinkedList();
        l.add(new Object());
        l.add("Hello");
        l.add("zhangsan");
        ListIterator li = l.listIterator(0);//迭代的对象生成器
        while (li.hasNext())//通过hasNext方法依次访问
            System.out.println(li.next());
        if (l.indexOf("Hello") < 0)   //通过l调用indexOf方法
            System.err.println("Lookup does not work");
        else
            System.err.println("Lookup works");
   }
}

l 在Elipse环境下编辑运行调试教材360页程序9-1，结合程序运行结果理解程序；

l 掌握ArrayList、LinkList两个类的用途及常用API。

import java.util.*;

/**
 * This program demonstrates operations on linked lists.
 * @version 1.11 2012-01-26
 * @author Cay Horstmann
 */
public class LinkedListTest
{
   public static void main(String[] args)
   {
       //创建a和b两个链表
      List<String> a = new LinkedList<>();//泛型
      a.add("Amy");
      a.add("Carl");
      a.add("Erica");

      List<String> b = new LinkedList<>();//泛型
      b.add("Bob");
      b.add("Doug");
      b.add("Frances");
      b.add("Gloria");

      //合并a和b中的词

      ListIterator<String> aIter = a.listIterator();
      Iterator<String> bIter = b.iterator();

      while (bIter.hasNext())
      {
         if (aIter.hasNext()) aIter.next();
         aIter.add(bIter.next());
      }

      System.out.println(a);

      //从第二个链表中每隔一个元素删除一个元素

      bIter = b.iterator();
      while (bIter.hasNext())
      {
         bIter.next(); // skip one element
         if (bIter.hasNext())
         {
            bIter.next(); // skip next element
            bIter.remove(); // remove that element
         }
      }

      System.out.println(b);

      // bulk operation: remove all words in b from a

      a.removeAll(b);

      System.out.println(a);//通过AbstractCollection类中的toString方法打印出链表a中的所有元素
   }
}

测试程序3：

l 运行SetDemo程序，结合运行结果理解程序；

import java.util.*;
public class SetDemo {
    public static void main(String[] argv) {
        HashSet h = new HashSet(); //也可以 Set h=new HashSet()
        h.add("One");
        h.add("Two");
        h.add("One"); // DUPLICATE
        h.add("Three");
        Iterator it = h.iterator();
        while (it.hasNext()) {
             System.out.println(it.next());
        }
    }
}

 

l 在Elipse环境下调试教材367页-368程序9-3、9-4，结合程序运行结果理解程序；了解TreeSet类的用途及常用API。

import java.util.*;

/**
 * An item with a description and a part number.
 */
public class Item implements Comparable<Item>//接口（泛型）
{
   private String description;
   private int partNumber;

   /**
    * Constructs an item.
    * 
    * @param aDescription
    *           the item's description
    * @param aPartNumber
    *           the item's part number
    */
   public Item(String aDescription, int aPartNumber)//构造器
   {
      description = aDescription;
      partNumber = aPartNumber;
   }

   /**
    * Gets the description of this item.
    * 
    * @return the description
    */
   public String getDescription()
   {
      return description;
   }

   public String toString()
   {
      return "[description=" + description + ", partNumber=" + partNumber + "]";
   }

   public boolean equals(Object otherObject)
   {
      if (this == otherObject) return true;
      if (otherObject == null) return false;
      if (getClass() != otherObject.getClass()) return false;
      Item other = (Item) otherObject;
      return Objects.equals(description, other.description) && partNumber == other.partNumber;
   }

   public int hashCode()
   {
      return Objects.hash(description, partNumber);
   }

   public int compareTo(Item other)//排序
   {
      int diff = Integer.compare(partNumber, other.partNumber);
      return diff != 0 ? diff : description.compareTo(other.description);
   }
}

import java.util.*;

/**
 * This program sorts a set of item by comparing their descriptions.
 * @version 1.12 2015-06-21
 * @author Cay Horstmann
 */
public class TreeSetTest
{
   public static void main(String[] args)
   {
      SortedSet<Item> parts = new TreeSet<>();
      parts.add(new Item("Toaster", 1234));
      parts.add(new Item("Widget", 4562));
      parts.add(new Item("Modem", 9912));
      System.out.println(parts);

      NavigableSet<Item> sortByDescription = new TreeSet<>(
            Comparator.comparing(Item::getDescription));//把自定义类对象存入TreeSet进行排序

      sortByDescription.addAll(parts);
      System.out.println(sortByDescription);
   }
}

测试程序4：

l 使用JDK命令运行HashMapDemo程序，结合程序运行结果理解程序；

程序如下：

import java.util.*;
public class HashMapDemo //基于哈希表的 Map接口的实现，提供所有可选的映射操作
{
   public static void main(String[] argv) {
      HashMap h = new HashMap();
      // 哈希映射从公司名称到地址
      h.put("Adobe", "Mountain View, CA");
      h.put("IBM", "White Plains, NY");
      h.put("Sun", "Mountain View, CA");
      String queryString = "Adobe";
      String resultString = (String)h.get(queryString);
      System.out.println("They are located in: " +  resultString);
  }
}

l 在Elipse环境下调试教材373页程序9-6，结合程序运行结果理解程序；

了解HashMap、TreeMap两个类的用途及常用API。

程序如下：

import java.util.*;

/**
 * This program demonstrates the use of a map with key type String and value type Employee.
 * @version 1.12 2015-06-21
 * @author Cay Horstmann
 */
public class MapTest//Map在有映射关系时，可以优先考虑
{
   public static void main(String[] args)
   {
      Map<String, Employee> staff = new HashMap<>();
      staff.put("144-25-5464", new Employee("Amy Lee"));
      staff.put("567-24-2546", new Employee("Harry Hacker"));
      staff.put("157-62-7935", new Employee("Gary Cooper"));
      staff.put("456-62-5527", new Employee("Francesca Cruz"));

      // 打印所有条目

      System.out.println(staff);

      // 删除一个条目

      staff.remove("567-24-2546");

      // 替换一个条目

      staff.put("456-62-5527", new Employee("Francesca Miller"));

      // 查找一个值

      System.out.println(staff.get("157-62-7935"));

      // 遍历所有条目

      staff.forEach((k, v) -> 
         System.out.println("key=" + k + ", value=" + v));
   }
}

实验2：结对编程练习：

l 关于结对编程：以下图片是一个结对编程场景：两位学习伙伴坐在一起，面对着同一台显示器，使用着同一键盘，同一个鼠标，他们一起思考问题，一起分析问题，一起编写程序。

l 关于结对编程的阐述可参见以下链接：

http://www.cnblogs.com/xinz/archive/2011/08/07/2130332.html

http://en.wikipedia.org/wiki/Pair_programming

l 对于结对编程中代码设计规范的要求参考：

http://www.cnblogs.com/xinz/archive/2011/11/20/2255971.html

以下实验，就让我们来体验一下结对编程的魅力。

l 确定本次实验结对编程合作伙伴：马凯军

l 各自运行合作伙伴实验九编程练习1，结合使用体验对所运行程序提出完善建议；

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.List;

import java.util.Scanner;

 

public class Xinxi {

    private static ArrayList<Student> studentlist;

 

     

    public static  void main(String[] args) {

        studentlist = new ArrayList<>();

        Scanner scanner = new Scanner(System.in);

        File file = new File("D:\身份证号\身份证号.txt");

        try {

            FileInputStream fis = new FileInputStream(file);

            BufferedReader in = new BufferedReader(new InputStreamReader(fis));

            String temp = null;

            while ((temp = in.readLine()) != null) {

 

                Scanner linescanner = new Scanner(temp);

 

                linescanner.useDelimiter(" ");

                String name = linescanner.next();

                String number = linescanner.next();

                String sex = linescanner.next();

                String age = linescanner.next();

                String province = linescanner.nextLine();

                Student student = new Student();

                student.setName(name);

                student.setnumber(number);

                student.setsex(sex);

                int a = Integer.parseInt(age);

                student.setage(a);

                student.setprovince(province);

                studentlist.add(student);

 

            }

        } catch (FileNotFoundException e) {//添加的异常处理语句try{   }catch{   }语句

            System.out.println("所找信息文件找不到");

            e.printStackTrace();

        } catch (IOException e) {

            System.out.println("所找信息文件读取错误");//采取积极方法捕获异常，并将异常返回自己所设定的打印文字

            e.printStackTrace();

        }

        boolean isTrue = true;

        while (isTrue) {

            System.out.println("选择你的操作，输入正确格式的选项");

            System.out.println("1按姓名字典序输出人员信息");

            System.out.println("2.查询最大和最小年龄的人员信息");

 

            System.out.println("3.寻找老乡");

            System.out.println("4.寻找年龄相近的人的信息");

 

            System.out.println("5.退出");

            String n = scanner.next();

            switch (n) {

            case "1":

                Collections.sort(studentlist);

                System.out.println(studentlist.toString());

                break;

            case "2":

                int max = 0, min = 100;

                int j, k1 = 0, k2 = 0;

                for (int i = 1; i < studentlist.size(); i++) {

                    j = studentlist.get(i).getage();

                    if (j > max) {

                        max = j;

                        k1 = i;

                    }

                    if (j < min) {

                        min = j;

                        k2 = i;

                    }

 

                }

                System.out.println("年龄最大：" + studentlist.get(k1));

 

                System.out.println("年龄最小：" + studentlist.get(k2));

                break;

            case "3":

                System.out.println("家乡在哪里？");

                String find = scanner.next();

                String place = find.substring(0, 3);

                for (int i = 0; i < studentlist.size(); i++) {

                    if (studentlist.get(i).getprovince().substring(1, 4).equals(place))

                        System.out.println("同乡" + studentlist.get(i));

                }

                break;

 

            case "4":

                System.out.println("年龄：");

                int yourage = scanner.nextInt();

                int near = agenear(yourage);

                int value = yourage - studentlist.get(near).getage();

                System.out.println("" + studentlist.get(near));

                break;

            case "5":

                isTrue = false;

                System.out.println("退出程序!");

                break;

            default:

                System.out.println("输入有误");

 

            }

        }

    }

 

    public static int agenear(int age) {

        int j = 0, min = 53, value = 0, flag = 0;

        for (int i = 0; i < studentlist.size(); i++) {

            value = studentlist.get(i).getage() - age;

            if (value < 0)

                value = -value;

            if (value < min) {

                min = value;

                flag = i;

            }

        }

        return flag;

    }

 

}

public  class Student implements Comparable<Student> {

 

    private String name;

    private String number;

    private String sex;

    private String province;

    private int age;

 

    public void setName(String name) {

        // TODO 自动生成的方法存根

        this.name = name;

 

    }

 

    public String getName() {

        // TODO 自动生成的方法存根

        return name;

    }

 

    public void setnumber(String number) {

        // TODO 自动生成的方法存根

        this.number = number;

    }

 

    public String getNumber() {

        // TODO 自动生成的方法存根

        return number;

    }

 

    public void setsex(String sex) {

        // TODO 自动生成的方法存根

        this.sex = sex;

    }

 

    public String getsex() {

        // TODO 自动生成的方法存根

        return sex;

    }

 

    public void setprovince(String province) {

        // TODO 自动生成的方法存根

        this.province = province;

    }

 

    public String getprovince() {

        // TODO 自动生成的方法存根

        return province;

    }

 

    public void setage(int a) {

        // TODO 自动生成的方法存根

        this.age = age;

    }

 

    public int getage() {

        // TODO 自动生成的方法存根

        return age;

    }

 

    public int compareTo(Student o) {

        return this.name.compareTo(o.getName());

    }

 

    public String toString() {

        return name + "	" + sex + "	" + age + "	" + number + "	" + province + "
";

    }

}

package 第九周;

import java.util.Random;

import java.util.Scanner;

import java.io.FileNotFoundException;

import java.io.PrintWriter;

 

    public class Demo {

        public static void main(String[] args) {

            // 用户的答案要从键盘输入，因此需要一个键盘输入流

            Scanner in = new Scanner(System.in);

            yunsuan counter = new yunsuan  ();

            PrintWriter out = null;

             

            try {

                out = new PrintWriter("D:\text.txt");

            } catch (FileNotFoundException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

            int sum = 0;

            // 通过循环生成10道题

            for (int i = 0; i < 10; i++) {

             

                 

                int a = (int) Math.round(Math.random() * 100);

                int b = (int) Math.round(Math.random() * 100);

                 

                //Scanner in1 =new Scanner(System.in);

                 

                Random rand=new Random();

                switch((int)(Math.random()*4)+1)

                 

                {

                 

                case 1:

                System.out.println( ""+a+"+"+b+"=");

                 

                int c= in.nextInt();

                out.println(a+"+"+b+"="+c);

                if (c == counter.add(a, b)) {

                    sum += 10;

                    System.out.println("恭喜答案正确");

                }

                else {

                    System.out.println("抱歉答案错误");

                }

                 

                break ;

                case 2:

                    while (a<b) {

                        b = (int)Math.round(Math.random() * 100); ;

                         

                    }

                System.out.println(i + ": " + a + "-" + b + "=");

                int c1 = in.nextInt();

                out.println(a + "-" + b + "=" + c1);

                if (c1 == counter.reduce(a, b)) {

                    sum += 10;

                    System.out.println("恭喜答案正确");

                } else {

                    System.out.println("抱歉答案错误");

                }

                break;

                case 3:

                System.out.println(i + ": " + a + "*" + b + "=");

                int c2 = in.nextInt();

                out.println(a + "*" + b + "=" + c2);

                if (c2 == counter.multiplication(a, b)) {

                    sum += 10;

                    System.out.println("恭喜答案正确");

                } else {

                    System.out.println("抱歉答案错误");

                }

                break;

                case 4:

                 

                a = b + (int) Math.round(Math.random() * 100);

                while(b==0)

                {  b = (int) Math.round(Math.random() * 100);

                }

                while (a%b==0) {

                     a= (int) Math.round(Math.random() * 100);    

                     

                }

                System.out.println(""+a+"/"+b+"=");

             int c3= in.nextInt();

             out.println(a+"/"+b+"="+c3);

             if (c3 == counter.devision(a, b)) {

                 sum += 10;

                 System.out.println("恭喜答案正确");

             }

             else {

                 System.out.println("抱歉答案错误");

             }

             break;

             }

            }

             

                System.out.println("总分:"+sum);

                out.println(sum);

                 

                out.close();

                }

                }

package 第九周;

 

public class yunsuan<T>{

    private T a;

    private T b;

    public yunsuan() {

        a=null;

        b=null;

    }

 

    public int multiplication(int a, int b) {

        // TODO 自动生成的方法存根

        return a*b;

    }

 

    public int add(int a, int b) {

        // TODO 自动生成的方法存根

        return a+b;

    }

 

    public int reduce(int a, int b) {

        // TODO 自动生成的方法存根

        if((a-b)>0)//保证两数相减不会是负数

        return a-b;

        else

            return 0;

    }

     

    public int devision(int a, int b) {

        // TODO 自动生成的方法存根

        if (b != 0 && a%b==0)//保证是整除

        return a/b;

        else

            return 0;

    }

 

}

l 采用结对编程方式，与学习伙伴合作完成实验九编程练习1；

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Scanner;

import java.util.Collections;//对集合进行排序、查找、修改等；

 

public class Test {

    private static ArrayList<Citizen> citizenlist;

 

    public static void main(String[] args) {

        citizenlist = new ArrayList<>();

        Scanner scanner = new Scanner(System.in);

        File file = new File("E:/java/身份证号.txt");

        //异常捕获

        try {

            FileInputStream fis = new FileInputStream(file);

            BufferedReader in = new BufferedReader(new InputStreamReader(fis));

            String temp = null;

            while ((temp = in.readLine()) != null) {

 

                Scanner linescanner = new Scanner(temp);

 

                linescanner.useDelimiter(" ");

                String name = linescanner.next();

                String id = linescanner.next();

                String sex = linescanner.next();

                String age = linescanner.next();

                String birthplace = linescanner.nextLine();

                Citizen citizen = new Citizen();

                citizen.setName(name);

                citizen.setId(id);

                citizen.setSex(sex);

                // 将字符串转换成10进制数

                int ag = Integer.parseInt(age);

                citizen.setage(ag);

                citizen.setBirthplace(birthplace);

                citizenlist.add(citizen);

 

            }

        } catch (FileNotFoundException e) {

            System.out.println("信息文件找不到");

            e.printStackTrace();

        } catch (IOException e) {

            System.out.println("信息文件读取错误");

            e.printStackTrace();

        }

        boolean isTrue = true;

        while (isTrue) {

 

            System.out.println("1.按姓名字典序输出人员信息");

            System.out.println("2.查询最大年龄的人员信息、查询最小年龄人员信息");

            System.out.println("3.查询人员中是否查询人员中是否有你的同乡");

            System.out.println("4.输入你的年龄，查询文件中年龄与你最近人的姓名、身份证号、年龄、性别和出生地");

            System.out.println("5.退出");

            int nextInt = scanner.nextInt();

            switch (nextInt) {

            case 1:

                Collections.sort(citizenlist);

                System.out.println(citizenlist.toString());

                break;

            case 2:

                int max = 0, min = 100;

                int m, k1 = 0, k2 = 0;

                for (int i = 1; i < citizenlist.size(); i++) {

                    m = citizenlist.get(i).getage();

                    if (m > max) {

                        max = m;

                        k1 = i;

                    }

                    if (m < min) {

                        min = m;

                        k2 = i;

                    }

                }

                System.out.println("年龄最大：" + citizenlist.get(k1));

                System.out.println("年龄最小：" + citizenlist.get(k2));

                break;

            case 3:

                System.out.println("出生地：");

                String find = scanner.next();

                String place = find.substring(0, 3);

                for (int i = 0; i < citizenlist.size(); i++) {

                    if (citizenlist.get(i).getBirthplace().substring(1, 4).equals(place))

                        System.out.println("出生地" + citizenlist.get(i));

                }

                break;

            case 4:

                System.out.println("年龄：");

                int yourage = scanner.nextInt();

                int near = peer(yourage);

                int j = yourage - citizenlist.get(near).getage();

                System.out.println("" + citizenlist.get(near));

                break;

            case 5:

                isTrue = false;

                System.out.println("程序已退出!");

                break;

            default:

                System.out.println("输入有误");

            }

        }

    }

 

    public static int peer(int age) {

        int flag = 0;

        int min = 53, j = 0;

        for (int i = 0; i < citizenlist.size(); i++) {

            j = citizenlist.get(i).getage() - age;

            if (j < 0)

                j = -j;

            if (j < min) {

                min = j;

                flag = i;

            }

        }

        return flag;

    }

}

public class Citizen implements Comparable<Citizen> {

 

    private String name;

    private String id;

    private String sex;

    private int age;

    private String birthplace;

 

    public String getName() {

        return name;

    }

 

    public void setName(String name) {

        this.name = name;

    }

 

    public String getId() {

        return id;

    }

 

    public void setId(String id) {

        this.id = id;

    }

 

    public String getSex() {

        return sex;

    }

 

    public void setSex(String sex) {

        this.sex = sex;

    }

 

    public int getage() {

        return age;

    }

 

    public void setage(int age) {

        this.age = age;

    }

 

    public String getBirthplace() {

        return birthplace;

    }

 

    public void setBirthplace(String birthplace) {

        this.birthplace = birthplace;

    }

 

    public int compareTo(Citizen other) {

        return this.name.compareTo(other.getName());

    }

 

    public String toString() {

        return name + "	" + sex + "	" + age + "	" + id + "	" + birthplace + "
";

    }

}

l 采用结对编程方式，与学习伙伴合作完成实验十编程练习2。

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.Scanner;

 

public class calculator {

 

    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);

        Count count=new Count();

        PrintWriter out = null;

        try {

            out = new PrintWriter("test.txt");

            int sum = 0;

            for (int i = 1; i <=10; i++) {

                int a = (int) Math.round(Math.random() * 100);

                int b = (int) Math.round(Math.random() * 100);

                int menu = (int) Math.round(Math.random() * 3);

                switch (menu) {

                case 0:

                    System.out.println(i+":"+a + "+" + b + "=");

                    int c1 = in.nextInt();

                    out.println(a + "+" + b + "=" + c1);

                    if (c1 == (a + b)) {

                        sum += 10;

                        System.out.println("恭喜答案正确");

                    } else {

                        System.out.println("抱歉，答案错误");

                    }

                    break;

                case 1:

                    while (a < b) {

                        b = (int) Math.round(Math.random() * 100);

                    }

                    System.out.println(i+":"+a + "-" + b + "=");

                    int c2 = in.nextInt();

                    out.println(a + "-" + b + "=" + c2);

                    if (c2 == (a - b)) {

                        sum += 10;

                        System.out.println("恭喜答案正确");

                    } else {

                        System.out.println("抱歉，答案错误");

                    }

 

                    break;

                case 2:

                    System.out.println(i+":"+a + "*" + b + "=");

                    int c3 = in.nextInt();

                    out.println(a + "*" + b + "=" + c3);

                    if (c3 == a * b) {

                        sum += 10;

                        System.out.println("恭喜答案正确");

                    } else {

                        System.out.println("抱歉，答案错误");

                    }

 

                    break;

                case 3:

                     while(b == 0){

                            b = (int) Math.round(Math.random() * 100);

                        }

                        while(a % b != 0){

                            a = (int) Math.round(Math.random() * 100);

                             

                        }

                    System.out.println(i+":"+a + "/" + b + "=");

                    int c4 = in.nextInt();

                    if (c4 == a / b) {

                        sum += 10;

                        System.out.println("恭喜答案正确");

                    } else {

                        System.out.println("抱歉，答案错误");

                    }

 

                    break;

                }

            }

            System.out.println("你的得分为" + sum);

            out.println("你的得分为" + sum);

            out.close();

        } catch (FileNotFoundException e) {

            e.printStackTrace();

        }

    }

 

}

public class Count<T> {

    private T a;

    private T b;

    public Count() {

        a=null;

        b=null;

    }

    public Count(T a,T b) {

        this.a=a;

        this.b=b;

    }

    public int count1(int a,int b) {

        return a+b;

    }

    public int count2(int a,int b) {

        return a-b;

    }

    public int count3(int a,int b) {

        return a*b;

    }

    public int count4(int a,int b) {

        return a/b;

    }

}

实验总结：

　　通过本周学习，我了解了集合框架，另外初步了解了java集合类，也了解了Vector类，Stack类以及Hashtable类。此次实验第一次采用结对编程的方法，通过和合作伙伴互相运行程序，相互讨论交流，从中学到了很多东西，也发现了很多不足。我们从伙伴对方学到东西，改正不足，继续努力。