201771010102 常惠琢《2018面向对象程序设计（Java）》第11周学习总结

时间：2018-11-11 13:14:53 阅读：254 评论：0 收藏：0 [点我收藏+]

标签：buffer trie any 运行年龄 adl try als ESS

实验十一 集合

实验时间 2018-11-8

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；

l 掌握Vetor、Stack、Hashtable三个类的用途及常用API。

//示例程序1

import java.util.Vector;

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();

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++)

((Cat) cats.elementAt(i)).print();

}

//示例程序2

import java.util.*;

public class Stacks {

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]);

System.out.println(stk);

System.out.println("element 2=" + stk.elementAt(2));

while (!stk.empty())

System.out.println(stk.pop());

}

//示例程序3

import java.util.*;

class Counter {

int i = 1;

public String toString() {

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));

if (ht.containsKey(r))

((Counter) ht.get(r)).i++;

else

ht.put(r, new Counter());

}

System.out.println(ht);

}

示例程序1：

 1 import java.util.Vector;
 2 
 3 public class CatsAndDogs {
 4     public static void main(String[] args) {
 5         Vector cats = new Vector();
 6         for (int i = 0; i < 7; i++)
 7             cats.addElement(new Cat(i));
 8         cats.addElement(new Dog(7));
 9         for (int i = 0; i < cats.size(); i++)
10             ((Cat) cats.elementAt(i)).print();
11     }
12 }

CatsAndDogs

 1 import java.util.Vector;
 2 
 3 class Cat {
 4     private int catNumber;
 5 
 6     Cat(int i) {
 7         catNumber = i;
 8     }
 9 
10     void print() {
11         System.out.println("Cat #" + catNumber);
12     }
13 }

Cat

 1 class Dog {
 2     private int dogNumber;
 3 
 4     Dog(int i) {
 5         dogNumber = i;
 6     }
 7 
 8     void print() {
 9         System.out.println("Dog #" + dogNumber);
10     }
11 }

Dog

技术分享图片

示例程序1异常处理：

 1 import java.util.Vector;
 2 
 3 class Cat {
 4     private int catNumber;
 5 
 6     Cat(int i) {
 7         catNumber = i;
 8     }
 9 
10     void print() {
11         System.out.println("Cat #" + catNumber);
12     }
13 }
14 
15 class Dog {
16     private int dogNumber;
17 
18     Dog(int i) {
19         dogNumber = i;
20     }
21 
22     void print() {
23         System.out.println("Dog #" + dogNumber);
24     }
25 }
26 
27 public class CatsAndDogs {
28     public static void main(String[] args) {
29         Vector cats = new Vector();
30         for (int i = 0; i < 7; i++)
31             cats.addElement(new Cat(i));
32         cats.addElement(new Dog(7));
33         for (int i = 0; i < cats.size(); i++)
34             if (cats.elementAt(i) instanceof Cat) {
35                 ((Cat) cats.elementAt(i)).print();
36             }
37             else {
38                 ((Dog) cats.elementAt(i)).print();
39             }
40     }
41 }

CatsAndDogs

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示例程序2：

 1 import java.util.*;
 2 
 3 public class Stacks {
 4     static String[] months = { "1", "2", "3", "4" };
 5 
 6     public static void main(String[] args) {
 7         Stack stk = new Stack();
 8         for (int i = 0; i < months.length; i++)
 9             stk.push(months[i]);
10         System.out.println(stk);
11         System.out.println("element 2=" + stk.elementAt(2));
12         while (!stk.empty())
13             System.out.println(stk.pop());
14     }
15 }

Stacks

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 1 import java.util.Hashtable;
 2 
 3 public class Statistics {
 4     public static void main(String[] args) {
 5         Hashtable ht = new Hashtable();
 6         for (int i = 0; i < 10000; i++) {
 7             Integer r = new Integer((int) (Math.random() * 20));
 8             if (ht.containsKey(r))
 9                 ((Counter) ht.get(r)).i++;
10             else
11                 ht.put(r, new Counter());
12         }
13         System.out.println(ht);
14     }
15 }

Statistics

1 import java.util.*;
2 
3 class Counter {
4     int i = 1;
5 
6     public String toString() {
7         return Integer.toString(i);
8     }
9 }

Counter

 1 import java.util.*;
 2 
 3 class Counter {
 4     int i = 1;//i未加访问权限修饰符。权限修饰符共有四种权限修饰符，分别是public，protected，默认和private。
 5 
 6     public String toString() {
 7         return Integer.toString(i);
 8     }
 9 }
10 
11 public class Statistics {
12     public static void main(String[] args) {
13         Hashtable ht = new Hashtable(); //创建了一个哈希表类对象
14         for (int i = 0; i < 10000; i++) {
15             Integer r = new Integer((int) (Math.random() * 20)); //生成20个整型随机数
16             if (ht.containsKey(r))//通过ht调用containsKey的方法
17                 ((Counter) ht.get(r)).i++;//通过Counter类对象引用i的属性
18             else
19                 ht.put(r, new Counter());//生成了一个Counter类对象，属性值为初始值。
20         }
21         System.out.println(ht);
22     }
23 }

Statistics

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测试程序2：

l 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；

import java.util.*;

public class ArrayListDemo {

public static void main(String[] argv) {

ArrayList al = new ArrayList();

// Add lots of elements to the ArrayList...

al.add(new Integer(11));

al.add(new Integer(12));

al.add(new Integer(13));

al.add(new String("hello"));

// 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);

while (li.hasNext())

System.out.println(li.next());

if (l.indexOf("Hello") < 0)

System.err.println("Lookup does not work");

else

System.err.println("Lookup works");

}

 1 import java.util.*;
 2 
 3 public class ArrayListDemo {
 4     public static void main(String[] argv) {
 5         ArrayList al = new ArrayList();
 6         // 向ARARYLIST中添加大量元素。
 7         al.add(new Integer(11));
 8         al.add(new Integer(12));
 9         al.add(new Integer(13));
10         al.add(new String("hello"));
11         // 首先用一个for循环打印出来。
12         System.out.println("Retrieving by index:");
13         for (int i = 0; i < al.size(); i++) {
14             System.out.println("Element " + i + " = " + al.get(i));
15         }
16     }
17 }

ArrayListDemo

 1 import java.util.*;
 2 public class LinkedListDemo {
 3     public static void main(String[] argv) {
 4         LinkedList l = new LinkedList();
 5         l.add(new Object());
 6         l.add("Hello");
 7         l.add("zhangsan");
 8         ListIterator li = l.listIterator(0);
 9         while (li.hasNext())
10             System.out.println(li.next());
11         if (l.indexOf("Hello") < 0)   
12             System.err.println("Lookup does not work");
13         else
14             System.err.println("Lookup works");
15    }
16 }

LinkedListDemo

技术分享图片

 1 import java.util.*;
 2 
 3 public class ArrayListDemo {
 4     public static void main(String[] argv) {
 5         ArrayList al = new ArrayList();
 6         // 向ARARYLIST中添加大量元素。
 7         al.add(new Integer(11));
 8         al.add(new Integer(12));
 9         al.add(new Integer(13));
10         al.add(new String("hello"));//集合中的元素可以是不同类对象
11         System.out.println(al.size());
12         // 首先用一个for循环打印出来。
13         System.out.println("Retrieving by index:");
14         for (int i = 0; i < al.size(); i++) {
15             System.out.println("Element " + i + " = " + al.get(i));
16         }
17     }
18 }

ArrayListDemo

技术分享图片

 1 import java.util.*;
 2 public class LinkedListDemo {
 3     public static void main(String[] argv) {
 4         LinkedList l = new LinkedList();
 5         l.add(new Object());
 6         l.add("Hello");
 7         l.add("zhangsan");
 8         ListIterator li = l.listIterator(0);
 9         while (li.hasNext())
10             System.out.println(li.next());
11         if (l.indexOf("Hello") < 0)   //是否为l中的索引值
12             System.err.println("Lookup does not work");
13         else
14             System.err.println("Lookup works");
15    }
16 }

LinkedListDemo

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。

 1 package linkedList;
 2 
 3 import java.util.*;
 4 
 5 /**
 6  * 这个程序演示了链表上的操作 
 7  * @version 1.11 2012-01-26
 8  * @author Cay Horstmann
 9  */
10 public class LinkedListTest
11 {
12    public static void main(String[] args)
13    {
14       List<String> a = new LinkedList<>();
15       a.add("Amy");
16       a.add("Carl");
17       a.add("Erica");
18 
19       List<String> b = new LinkedList<>();
20       b.add("Bob");
21       b.add("Doug");
22       b.add("Frances");
23       b.add("Gloria");
24 
25       //将单词从B合并为A 
26 
27       ListIterator<String> aIter = a.listIterator();
28       Iterator<String> bIter = b.iterator();
29 
30       while (bIter.hasNext())
31       {
32          if (aIter.hasNext()) aIter.next();
33          aIter.add(bIter.next());
34       }
35 
36       System.out.println(a);
37 
38       // remove every second word from b
39 
40       bIter = b.iterator();
41       while (bIter.hasNext())
42       {
43          bIter.next(); // 跳过一个元素
44          if (bIter.hasNext())
45          {
46             bIter.next(); // 跳过下一元素 
47             bIter.remove(); // 删除该元素 
48          }
49       }
50 
51       System.out.println(b);
52 
53       //批量操作：从A中删除B中的所有单词 
54 
55       a.removeAll(b);
56 
57       System.out.println(a);
58    }
59 }

View Code

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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());

}

 1 import java.util.HashSet;
 2 import java.util.Iterator;
 3 public class SetDemo {
 4     public static void main(String[] argv) {
 5         HashSet h = new HashSet(); //也可以 Set h=new HashSet()
 6         h.add("One");
 7         h.add("Two");
 8         h.add("One"); // DUPLICATE   重复; 复制; 复印; 打印；
 9         h.add("Three");
10         Iterator it = h.iterator();
11         while (it.hasNext()) {
12              System.out.println(it.next());
13         }
14     }
15 }

SetDemo

技术分享图片

l 在Elipse环境下调试教材365页程序9-2，结合运行结果理解程序；了解HashSet类的用途及常用API。

 1 package set;
 2 
 3 import java.util.*;
 4 
 5 /**
 6  *这个程序使用一个集合来打印System.in中所有唯一的单词
 7  * @version 1.12 2015-06-21
 8  * @author Cay Horstmann
 9  */
10 public class SetTest
11 {
12    public static void main(String[] args)
13    {
14       Set<String> words = new HashSet<>(); //哈希集实现集
15       long totalTime = 0;
16 
17       try (Scanner in = new Scanner(System.in))
18       {
19          while (in.hasNext())
20          {
21             String word = in.next();
22             long callTime = System.currentTimeMillis();
23             words.add(word);
24             callTime = System.currentTimeMillis() - callTime;
25             totalTime += callTime;
26          }
27       }
28 
29       Iterator<String> iter = words.iterator();
30       for (int i = 1; i <= 20 && iter.hasNext(); i++)
31          System.out.println(iter.next());
32       System.out.println(". . .");
33       System.out.println(words.size() + " distinct words. " + totalTime + " milliseconds.");
34    }
35 }

SetTest

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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。

 1 import java.util.*;
 2 
 3 /**
 4  * 该程序通过比较它们的描述对一组项目进行排序。
 5  * @version 1.12 2015-06-21
 6  * @author Cay Horstmann
 7  */
 8 public class TreeSetTest
 9 {
10    public static void main(String[] args)
11    {
12       SortedSet<Item> parts = new TreeSet<>();
13       parts.add(new Item("Toaster", 1234));
14       parts.add(new Item("Widget", 4562));
15       parts.add(new Item("Modem", 9912));
16       System.out.println(parts);
17 
18       NavigableSet<Item> sortByDescription = new TreeSet<>(
19             Comparator.comparing(Item::getDescription));
20 
21       sortByDescription.addAll(parts);
22       System.out.println(sortByDescription);
23    }
24 }

TreeSetTest

 1 package treeSet;
 2 
 3 import java.util.*;
 4 
 5 /**
 6  * 具有描述和零件编号的项目
 7  */
 8 public class Item implements Comparable<Item>
 9 {
10    private String description;
11    private int partNumber;
12 
13    /**
14     * 构造一个项目
15     * 
16     * @param aDescription
17     *           the item‘s description
18     * @param aPartNumber
19     *           the item‘s part number
20     */
21    public Item(String aDescription, int aPartNumber)
22    {
23       description = aDescription;
24       partNumber = aPartNumber;
25    }
26 
27    /**
28     * 获取此项的说明。
29     * 
30     * @返回描述 
31     */
32    public String getDescription()
33    {
34       return description;
35    }
36 
37    public String toString()
38    {
39       return "[description=" + description + ", partNumber=" + partNumber + "]";
40    }
41 
42    public boolean equals(Object otherObject)
43    {
44       if (this == otherObject) return true;
45       if (otherObject == null) return false;
46       if (getClass() != otherObject.getClass()) return false;
47       Item other = (Item) otherObject;
48       return Objects.equals(description, other.description) && partNumber == other.partNumber;
49    }
50 
51    public int hashCode()
52    {
53       return Objects.hash(description, partNumber);
54    }
55 
56    public int compareTo(Item other)
57    {
58       int diff = Integer.compare(partNumber, other.partNumber);
59       return diff != 0 ? diff : description.compareTo(other.description);
60    }
61 }

Item

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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；

import java.util.*;

public class HashMapDemo {

public static void main(String[] argv) {

HashMap h = new HashMap();

// The hash maps from company name to address.

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);

}

 1 import java.util.*;
 2 public class HashMapDemo {
 3    public static void main(String[] argv) {
 4       HashMap h = new HashMap();
 5       // 从公司名称到地址的哈希映射。
 6       h.put("Adobe", "Mountain View, CA");
 7       h.put("IBM", "White Plains, NY");
 8       h.put("Sun", "Mountain View, CA");
 9       String queryString = "Adobe";
10       String resultString = (String)h.get(queryString);
11       System.out.println("They are located in: " +  resultString);
12   }
13 }

HashMapDemo

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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；

l 了解HashMap、TreeMap两个类的用途及常用API。

 1 package map;
 2 
 3 import java.util.*;
 4 
 5 /**
 6  * This program demonstrates the use of a map with key type String and value type Employee.
 7  * @version 1.12 2015-06-21
 8  * @author Cay Horstmann
 9  */
10 public class MapTest
11 {
12    public static void main(String[] args)
13    {
14       Map<String, Employee> staff = new HashMap<>();
15       staff.put("144-25-5464", new Employee("Amy Lee"));
16       staff.put("567-24-2546", new Employee("Harry Hacker"));
17       staff.put("157-62-7935", new Employee("Gary Cooper"));
18       staff.put("456-62-5527", new Employee("Francesca Cruz"));
19 
20       //打印所有条目 
21 
22       System.out.println(staff);
23 
24       // 删除条目 
25 
26       staff.remove("567-24-2546");
27 
28       // 替换条目 
29 
30       staff.put("456-62-5527", new Employee("Francesca Miller"));
31 
32       // 查找一个值 
33 
34       System.out.println(staff.get("157-62-7935"));
35 
36       // 遍历所有条目 
37 
38       staff.forEach((k, v) -> 
39          System.out.println("key=" + k + ", value=" + v));
40    }
41 }

MapTest

 1 package map;
 2 
 3 /**
 4  * 用于测试目的的极简主义雇员类。
 5  */
 6 public class Employee
 7 {
 8    private String name;
 9    private double salary;
10 
11    /**
12     * 建造一个工资0美元的员工。
13     * @param n the employee name
14     */
15    public Employee(String name)
16    {
17       this.name = name;
18       salary = 0;
19    }
20 
21    public String toString()
22    {
23       return "[name=" + name + ", salary=" + salary + "]";
24    }
25 }

Employee

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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；

常惠琢和杨其菊

l 各自运行合作伙伴实验九编程练习1，

  1 import java.io.BufferedReader;
  2         import java.io.File;
  3         import java.io.FileInputStream;
  4         import java.io.FileNotFoundException;
  5         import java.io.IOException;
  6         import java.io.InputStreamReader;
  7         import java.util.ArrayList;
  8         import java.util.Arrays;
  9         import java.util.Collections;
 10         import java.util.Scanner;
 11 
 12 public class Test {
 13     private static ArrayList<Student> studentlist;
 14     public static void main(String[] args) {
 15 
 16                 studentlist = new ArrayList<>();
 17                 Scanner scanner = new Scanner(System.in);
 18                 File file = new File("F:\\java\\身份证号.txt");
 19                 try {
 20                     FileInputStream fis = new FileInputStream(file);
 21                     BufferedReader in = new BufferedReader(new InputStreamReader(fis));
 22                     String temp = null;
 23                     while ((temp = in.readLine()) != null) {
 24                         
 25                         Scanner linescanner = new Scanner(temp);
 26                         
 27                         linescanner.useDelimiter(" ");    
 28                         String name = linescanner.next();
 29                         String number = linescanner.next();
 30                         String sex = linescanner.next();
 31                         String age = linescanner.next();
 32                         String province =linescanner.nextLine();
 33                         Student student = new Student();
 34                         student.setName(name);
 35                         student.setnumber(number);
 36                         student.setsex(sex);
 37                         int a = Integer.parseInt(age);
 38                         student.setage(a);
 39                         student.setprovince(province);
 40                         studentlist.add(student);
 41 
 42                     }
 43                 } catch (FileNotFoundException e) {
 44                     System.out.println("找不到学生的信息文件");
 45                     e.printStackTrace();
 46                 } catch (IOException e) {
 47                     System.out.println("学生信息文件读取错误");
 48                     e.printStackTrace();
 49                 }
 50                 boolean isTrue = true;
 51                 while (isTrue) {
 52                     System.out.println("选择你的操作， ");
 53                     System.out.println("1.字典排序  ");
 54                     System.out.println("2.输出年龄最大和年龄最小的人  ");
 55                     System.out.println("3.寻找同乡  ");
 56                     System.out.println("4.寻找年龄相近的人  ");
 57                     System.out.println("5.退出 ");
 58                     String m = scanner.next();
 59                     switch (m) {
 60                     case "1":
 61                         Collections.sort(studentlist);              
 62                         System.out.println(studentlist.toString());
 63                         break;
 64                     case "2":
 65                          int max=0,min=100;
 66                          int j,k1 = 0,k2=0;
 67                          for(int i=1;i<studentlist.size();i++)
 68                          {
 69                              j=studentlist.get(i).getage();
 70                          if(j>max)
 71                          {
 72                              max=j; 
 73                              k1=i;
 74                          }
 75                          if(j<min)
 76                          {
 77                            min=j; 
 78                            k2=i;
 79                          }
 80                          
 81                          }  
 82                          System.out.println("年龄最大："+studentlist.get(k1));
 83                          System.out.println("年龄最小："+studentlist.get(k2));
 84                         break;
 85                     case "3":
 86                          System.out.println("地址?");
 87                          String find = scanner.next();        
 88                          String place=find.substring(0,3);
 89                          for (int i = 0; i <studentlist.size(); i++) 
 90                          {
 91                              if(studentlist.get(i).getprovince().substring(1,4).equals(place)) 
 92                                  System.out.println("同乡"+studentlist.get(i));
 93                          }             
 94                          break;
 95                          
 96                     case "4":
 97                         System.out.println("年龄：");
 98                         int yourage = scanner.nextInt();
 99                         int near=agenear(yourage);
100                         int value=yourage-studentlist.get(near).getage();
101                         System.out.println(""+studentlist.get(near));
102                         break;
103                     case "5 ":
104                         isTrue = false;
105                         System.out.println("退出程序!");
106                         break;
107                         default:
108                         System.out.println("输入有误");
109 
110                     }
111                 }
112             }
113                 public static int agenear(int age) {      
114                 int j=0,min=53,value=0,ok=0;
115                  for (int i = 0; i < studentlist.size(); i++)
116                  {
117                      value=studentlist.get(i).getage()-age;
118                      if(value<0) value=-value; 
119                      if (value<min) 
120                      {
121                         min=value;
122                          ok=i;
123                      } 
124                   }    
125                  return ok;         
126               }
127         }

Test

 1 public class Student implements Comparable<Student> {
 2 
 3     private String name;
 4     private String number ;
 5     private String sex ;
 6     private int age;
 7     private String province;
 8    
 9     public String getName() {
10         return name;
11     }
12     public void setName(String name) {
13         this.name = name;
14     }
15     public String getnumber() {
16         return number;
17     }
18     public void setnumber(String number) {
19         this.number = number;
20     }
21     public String getsex() {
22         return sex ;
23     }
24     public void setsex(String sex ) {
25         this.sex =sex ;
26     }
27     public int getage() {
28 
29         return age;
30         }
31         public void setage(int age) {
32             // int a = Integer.parseInt(age);
33         this.age= age;
34         }
35 
36     public String getprovince() {
37         return province;
38     }
39     public void setprovince(String province) {
40         this.province=province ;
41     }
42 
43     public int compareTo(Student o) {
44        return this.name.compareTo(o.getName());
45     }
46 
47     public String toString() {
48         return  name+"\t"+sex+"\t"+age+"\t"+number+"\t"+province+"\n";
49     }    
50 }

Student

技术分享图片

  1 package Second;
  2 import java.io.BufferedReader;
  3 import java.io.File;
  4 import java.io.FileInputStream;
  5 import java.io.FileNotFoundException;
  6 import java.io.IOException;
  7 import java.io.InputStreamReader;
  8 import java.util.ArrayList;
  9 import java.util.Arrays;
 10 import java.util.Collections;
 11 import java.util.Scanner;
 12 
 13 
 14 public class Search{
 15 
 16 private static ArrayList<Person> Personlist1;
 17 public static void main(String[] args) {
 18  
 19   Personlist1 = new ArrayList<>();
 20  
 21   Scanner scanner = new Scanner(System.in);
 22   File file = new File("E:\\面向对象程序设计Java\\实验\\实验六\\身份证号.txt");
 23 
 24         try {
 25              FileInputStream F = new FileInputStream(file);
 26              BufferedReader in = new BufferedReader(new InputStreamReader(F));
 27              String temp = null;
 28              while ((temp = in.readLine()) != null) {
 29                 
 30                 Scanner linescanner = new Scanner(temp);
 31                 
 32                 linescanner.useDelimiter(" ");    
 33                 String name = linescanner.next();
 34                 String id = linescanner.next();
 35                 String sex = linescanner.next();
 36                 String age = linescanner.next();
 37                 String place =linescanner.nextLine();
 38                 Person Person = new Person();
 39                 Person.setname(name);
 40                 Person.setid(id);
 41                 Person.setsex(sex);
 42                 int a = Integer.parseInt(age);
 43                 Person.setage(a);
 44                 Person.setbirthplace(place);
 45                 Personlist1.add(Person);
 46 
 47             }
 48         } catch (FileNotFoundException e) {
 49             System.out.println("查找不到信息");
 50             e.printStackTrace();
 51         } catch (IOException e) {
 52             System.out.println("信息读取有误");
 53             e.printStackTrace();
 54         }
 55         boolean isTrue = true;
 56         while (isTrue) {
 57             System.out.println("******************************************");
 58             System.out.println("1:按姓名字典顺序输出信息；");
 59             System.out.println("2:查询最大年龄与最小年龄人员信息；");
 60             System.out.println("3：按省份找你的同乡；");
 61             System.out.println("4:输入你的年龄,查询年龄与你最近人的信息；");
 62             System.out.println("5：退出");
 63             System.out.println("******************************************");
 64             int type = scanner.nextInt();
 65             switch (type) {
 66             case 1:
 67                 Collections.sort(Personlist1);
 68                 System.out.println(Personlist1.toString());
 69                 break;
 70             case 2:
 71                 
 72                 int max=0,min=100;int j,k1 = 0,k2=0;
 73                 for(int i=1;i<Personlist1.size();i++)
 74                 {
 75                     j=Personlist1.get(i).getage();
 76                    if(j>max)
 77                    {
 78                        max=j; 
 79                        k1=i;
 80                    }
 81                    if(j<min)
 82                    {
 83                        min=j; 
 84                        k2=i;
 85                    }
 86 
 87                 }  
 88                 System.out.println("年龄最大："+Personlist1.get(k1));
 89                 System.out.println("年龄最小："+Personlist1.get(k2));
 90                 break;
 91             case 3:
 92                 System.out.println("place?");
 93                 String find = scanner.next();        
 94                 String place=find.substring(0,3);
 95                 String place2=find.substring(0,3);
 96                 for (int i = 0; i <Personlist1.size(); i++) 
 97                 {
 98                     if(Personlist1.get(i).getbirthplace().substring(1,4).equals(place)) 
 99                     {
100                         System.out.println("你的同乡："+Personlist1.get(i));
101                     }
102                 } 
103 
104                 break;
105             case 4:
106                 System.out.println("年龄：");
107                 int yourage = scanner.nextInt();
108                 int close=ageclose(yourage);
109                 int d_value=yourage-Personlist1.get(close).getage();
110                 System.out.println(""+Personlist1.get(close));
111           
112                 break;
113             case 5:
114            isTrue = false;
115            System.out.println("再见!");
116                 break;
117             default:
118                 System.out.println("输入有误");
119             }
120         }
121     }
122     public static int ageclose(int age) {
123            int m=0;
124         int    max=53;
125         int d_value=0;
126         int k=0;
127         for (int i = 0; i < Personlist1.size(); i++)
128         {
129             d_value=Personlist1.get(i).getage()-age;
130             if(d_value<0) d_value=-d_value; 
131             if (d_value<max) 
132             {
133                max=d_value;
134                k=i;
135             }
136 
137          }    return k;
138         
139      }
140 }

 1 package Second;
 2 
 3 //jiekouwenjiaan
 4 
 5 
 6 public class Person implements Comparable<Person> {
 7   private String name;
 8   private String id;
 9   private int age;
10   private String sex;
11   private String birthplace;
12 
13 public String getname() {
14 return name;
15 }
16 public void setname(String name) {
17 this.name = name;
18 }
19 public String getid() {
20 return id;
21 }
22 public void setid(String id) {
23 this.id= id;
24 }
25 public int getage() {
26 
27 return age;
28 }
29 public void setage(int age) {
30 //int a = Integer.parseInt(age);
31 this.age= age;
32 }
33 public String getsex() {
34 return sex;
35 }
36 public void setsex(String sex) {
37 this.sex= sex;
38 }
39 public String getbirthplace() {
40 return birthplace;
41 }
42 public void setbirthplace(String birthplace) {
43 this.birthplace= birthplace;
44 }
45 
46 public int compareTo(Person o) {
47 return this.name.compareTo(o.getname());
48 
49 }
50 
51 public String toString() {
52 return  name+"\t"+sex+"\t"+age+"\t"+id+"\t";

Person

技术分享图片

结合使用体验对所运行程序提出完善建议；

实验九：

1.文件输出字体格式不一致，在整体美观上尚可修改。

2.编程过程存在变量使用混乱不清的问题。

l 各自运行合作伙伴实验十编程练习2，

  1 package a;
  2 
  3 import java.io.FileNotFoundException;
  4 import java.io.PrintWriter;
  5 import java.util.Scanner;
  6 
  7 //import org.w3c.dom.css.Counter;
  8 
  9 
 10 public class Main{
 11     public static void main(String[] args) {
 12 
 13         Scanner in = new Scanner(System.in);
 14         counter Counter=new  counter();
 15         PrintWriter output = null;
 16         try {
 17             output = new PrintWriter("result.txt");
 18         } catch (Exception e) {
 19             //e.printStackTrace();
 20         }
 21         int sum = 0;
 22 
 23         for (int i = 1; i <=10; i++) {
 24             int a = (int) Math.round(Math.random() * 100);
 25             int b = (int) Math.round(Math.random() * 100);
 26             int type = (int) Math.round(Math.random() * 4);
 27            
 28             
 29            switch(type)
 30            {
 31            case 1:
 32                
 33                System.out.println(i+": "+a+"/"+b+"=");
 34                while(b== 0&& a%b!=0)
 35                {  
 36                    b = (int) Math.round(Math.random() * 100); 
 37                    a = (int) Math.round(Math.random() * 100);
 38                    }   
 39                
 40                int c = in.nextInt();
 41                output.println(a+"/"+b+"="+c);
 42                if (c == Counter.Chu(a, b)) 
 43                {
 44                    sum += 10;
 45                    System.out.println("恭喜答案正确!");
 46                }
 47                else {
 48                    System.out.println("答案错误!");
 49                } 
 50                    break;
 51            
 52            case 2:
 53                System.out.println(i+": "+a+"*"+b+"=");
 54                int c1 = in.nextInt();
 55                output.println(a+"*"+b+"="+c1);
 56                if (c1 == Counter.Cheng(a, b)) {
 57                    sum += 10;
 58                    System.out.println("恭喜答案正确!");
 59                }
 60                else {
 61                    System.out.println("答案错误!");
 62                }
 63                break;
 64            case 3:
 65                System.out.println(i+": "+a+"+"+b+"=");
 66                int c2 = in.nextInt();
 67                output.println(a+"+"+b+"="+c2);
 68               
 69                if (c2 ==  Counter.Jia(a, b)) {
 70                    sum += 10;
 71                    System.out.println("恭喜答案正确!");
 72                }
 73                else {
 74                    System.out.println("答案错误!");
 75                }
 76                break ;
 77                
 78                
 79            case 4:
 80                
 81                while (a < b) {
 82                    int x=0;
 83                    x=b;
 84                    b=a;
 85                    a=x;
 86                }
 87                System.out.println(i+": "+a+"-"+b+"=");
 88                int c3 = in.nextInt();
 89                output.println(a+"-"+b+"="+c3);
 90                if (c3 ==  Counter.Jian(a, b)) 
 91                {
 92                    sum += 10;
 93                    System.out.println("恭喜答案正确!");
 94                }
 95                else {
 96                    System.out.println("答案错误!");
 97                }
 98                break ;
 99 
100              } 
101     
102           }
103         System.out.println("成绩"+sum);
104         output.println("成绩:"+sum);
105         output.close();
106          
107     }
108 }

Main

 1 package a;
 2 
 3 
 4 public class counter<T>{
 5        private T a;
 6        private T b;
 7        
 8        public counter(T a, T b) {
 9             this.a = a;
10             this.b = b;
11         }
12 
13                public counter() {
14         // TODO Auto-generated constructor stub
15     }
16 
17             public int  Jia(int a,int b)
18                {
19                    return a+b;
20                }
21                public int  Jian(int a,int b)
22                {
23                    return a-b;
24                        
25                  
26                }
27                public int   Cheng(int a,int b)
28                {
29                    return a*b;
30                }
31                public int   Chu(int a,int b)
32                {
33                    if (b!= 0 && a%b==0)
34                        return a / b;
35                    else
36                        return 0;  
37                    
38                }
39 
40                
41        }

counter

技术分享图片

结合使用体验对所运行程序提出完善建议；

   实验十
   1.没有全面考虑小学生的实际状况：减法算法结果可能出现负数的情况，以及除法的运算结果直接取整输出，都不符合小学生的学习范围；
   2.编程过程中，关于变量的使用混乱问题；
   3.结果没有输出到文件中；

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；

  1 package Second;
  2 import java.io.BufferedReader;
  3 import java.io.File;
  4 import java.io.FileInputStream;
  5 import java.io.FileNotFoundException;
  6 import java.io.IOException;
  7 import java.io.InputStreamReader;
  8 import java.util.ArrayList;
  9 import java.util.Arrays;
 10 import java.util.Collections;
 11 import java.util.Scanner;
 12 
 13 
 14 public class Search{
 15 
 16 private static ArrayList<Person> Personlist1;
 17 public static void main(String[] args) {
 18  
 19   Personlist1 = new ArrayList<>();
 20  
 21   Scanner scanner = new Scanner(System.in);
 22   File file = new File("E:\\面向对象程序设计Java\\实验\\实验六\\身份证号.txt");
 23 
 24         try {
 25              FileInputStream F = new FileInputStream(file);
 26              BufferedReader in = new BufferedReader(new InputStreamReader(F));
 27              String temp = null;
 28              while ((temp = in.readLine()) != null) {
 29                 
 30                 Scanner linescanner = new Scanner(temp);
 31                 
 32                 linescanner.useDelimiter(" ");    
 33                 String name = linescanner.next();
 34                 String id = linescanner.next();
 35                 String sex = linescanner.next();
 36                 String age = linescanner.next();
 37                 String place =linescanner.nextLine();
 38                 Person Person = new Person();
 39                 Person.setname(name);
 40                 Person.setid(id);
 41                 Person.setsex(sex);
 42                 int a = Integer.parseInt(age);
 43                 Person.setage(a);
 44                 Person.setbirthplace(place);
 45                 Personlist1.add(Person);
 46 
 47             }
 48         } catch (FileNotFoundException e) {
 49             System.out.println("查找不到信息");
 50             e.printStackTrace();
 51         } catch (IOException e) {
 52             System.out.println("信息读取有误");
 53             e.printStackTrace();
 54         }
 55         boolean isTrue = true;
 56         while (isTrue) {
 57             System.out.println("******************************************");
 58             System.out.println("1:按姓名字典顺序输出信息；");
 59             System.out.println("2:查询最大年龄与最小年龄人员信息；");
 60             System.out.println("3：按省份找你的同乡；");
 61             System.out.println("4:输入你的年龄,查询年龄与你最近人的信息；");
 62             System.out.println("5：退出");
 63             System.out.println("******************************************");
 64             int type = scanner.nextInt();
 65             switch (type) {
 66             case 1:
 67                 Collections.sort(Personlist1);
 68                 System.out.println(Personlist1.toString());
 69                 break;
 70             case 2:
 71                 
 72                 int max=0,min=100;int j,k1 = 0,k2=0;
 73                 for(int i=1;i<Personlist1.size();i++)
 74                 {
 75                     j=Personlist1.get(i).getage();
 76                    if(j>max)
 77                    {
 78                        max=j; 
 79                        k1=i;
 80                    }
 81                    if(j<min)
 82                    {
 83                        min=j; 
 84                        k2=i;
 85                    }
 86 
 87                 }  
 88                 System.out.println("年龄最大："+Personlist1.get(k1));
 89                 System.out.println("年龄最小："+Personlist1.get(k2));
 90                 break;
 91             case 3:
 92                 System.out.println("place?");
 93                 String find = scanner.next();        
 94                 String place=find.substring(0,3);
 95                 String place2=find.substring(0,3);
 96                 for (int i = 0; i <Personlist1.size(); i++) 
 97                 {
 98                     if(Personlist1.get(i).getbirthplace().substring(1,4).equals(place)) 
 99                     {
100                         System.out.println("你的同乡："+Personlist1.get(i));
101                     }
102                 } 
103 
104                 break;
105             case 4:
106                 System.out.println("年龄：");
107                 int yourage = scanner.nextInt();
108                 int close=ageclose(yourage);
109                 int d_value=yourage-Personlist1.get(close).getage();
110                 System.out.println(""+Personlist1.get(close));
111           
112                 break;
113             case 5:
114            isTrue = false;
115            System.out.println("再见!");
116                 break;
117             default:
118                 System.out.println("输入有误");
119             }
120         }
121     }
122     public static int ageclose(int age) {
123            int m=0;
124         int    max=53;
125         int d_value=0;
126         int k=0;
127         for (int i = 0; i < Personlist1.size(); i++)
128         {
129             d_value=Personlist1.get(i).getage()-age;
130             if(d_value<0) d_value=-d_value; 
131             if (d_value<max) 
132             {
133                max=d_value;
134                k=i;
135             }
136 
137          }    return k;
138         
139      }
140 }

 1 package Second;
 2 
 3 //jiekouwenjiaan
 4 
 5 
 6 public class Person implements Comparable<Person> {
 7   private String name;
 8   private String id;
 9   private int age;
10   private String sex;
11   private String birthplace;
12 
13 public String getname() {
14 return name;
15 }
16 public void setname(String name) {
17 this.name = name;
18 }
19 public String getid() {
20 return id;
21 }
22 public void setid(String id) {
23 this.id= id;
24 }
25 public int getage() {
26 
27 return age;
28 }
29 public void setage(int age) {
30 //int a = Integer.parseInt(age);
31 this.age= age;
32 }
33 public String getsex() {
34 return sex;
35 }
36 public void setsex(String sex) {
37 this.sex= sex;
38 }
39 public String getbirthplace() {
40 return birthplace;
41 }
42 public void setbirthplace(String birthplace) {
43 this.birthplace= birthplace;
44 }
45 
46 public int compareTo(Person o) {
47 return this.name.compareTo(o.getname());
48 
49 }
50 
51 public String toString() {
52 return  name+"\t"+sex+"\t"+age+"\t"+id+"\t";

Person

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。

 1 package A;
 2 
 3 import java.io.FileNotFoundException;
 4 import java.io.IOException;
 5 import java.io.PrintWriter;
 6 import java.util.Scanner;
 7 public class Main {
 8 
 9     public static void main(String[] args) {
10                 Scanner in = new Scanner(System.in);
11                 counter min=new counter();
12                 PrintWriter out = null;
13                 try {
14                     out = new PrintWriter("result.txt");
15                     int sum = 0;
16                     for (int i = 1; i <=10; i++) {
17                         int a = (int) Math.round(Math.random() * 100);
18                         int b = (int) Math.round(Math.random() * 100);
19                         int menu = (int) Math.round(Math.random() * 3);
20                         switch (menu) {
21                         case 0:
22                             System.out.println(i+":"+a + "+" + b + "=");
23                             int c1 = in.nextInt();
24                             out.println(a + "+" + b + "=" + c1);
25                             if (c1 == (a + b)) {
26                                 sum += 10;
27                                 System.out.println("恭喜答案正确");
28                             } else {
29                                 System.out.println("抱歉，答案错误");
30                             }
31                             break;
32                         case 1:
33                             while (a < b) {
34                                 b = (int) Math.round(Math.random() * 100);
35                             }
36                             System.out.println(i+":"+a + "-" + b + "=");
37                             int c2 = in.nextInt();
38                             out.println(a + "-" + b + "=" + c2);
39                             if (c2 == (a - b)) {
40                                 sum += 10;
41                                 System.out.println("恭喜答案正确");
42                             } else {
43                                 System.out.println("抱歉，答案错误");
44                             }
45 
46                             break;
47                         case 2:
48                             System.out.println(i+":"+a + "*" + b + "=");
49                             int c3 = in.nextInt();
50                             out.println(a + "*" + b + "=" + c3);
51                             if (c3 == a * b) {
52                                 sum += 10;
53                                 System.out.println("恭喜答案正确");
54                             } else {
55                                 System.out.println("抱歉，答案错误");
56                             }
57 
58                             break;
59                         case 3:
60                              while(b == 0){
61                                     b = (int) Math.round(Math.random() * 100);
62                                 }
63                                 while(a % b != 0){
64                                     a = (int) Math.round(Math.random() * 100);
65                                     
66                                 }
67                             System.out.println(i+":"+a + "/" + b + "=");
68                             int c4 = in.nextInt();
69                             if (c4 == a / b) {
70                                 sum += 10;
71                                 System.out.println("恭喜，答案正确");
72                             } else {
73                                 System.out.println("抱歉，答案错误");
74                             }
75 
76                             break;
77                         }
78                     }
79                     System.out.println("你的得分为" + sum);
80                     out.println("你的得分为" + sum);
81                     out.close();
82                 } catch (FileNotFoundException e) {
83                     e.printStackTrace();
84                 }
85             }
86         }

Main

 1 package A;
 2 
 3 public class counter<T> {
 4     private T a;
 5     private T b;
 6     public counter() {
 7         a=null;
 8         b=null;
 9     }
10     public counter(T a,T b) {
11         this.a=a;
12         this.b=b;
13     }
14     public int count1(int a,int b) {
15         return a+b;
16     }
17     public int count2(int a,int b) {
18         return a-b;
19     }
20     public int count3(int a,int b) {
21         return a*b;
22     }
23     public int count4(int a,int b) {
24         return a/b;
25     }
26 }

counter

技术分享图片

实验总结：

这次实验完成后，感觉结对实验会更有收获，不管是从所得的分享，还是共同完成一个实验，都有一些的收获。

201771010102 常惠琢《2018面向对象程序设计（Java）》第11周学习总结

标签：buffer trie any 运行年龄 adl try als ESS

原文地址：https://www.cnblogs.com/hongyanohongyan/p/9929216.html

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201771010102 常惠琢 《2018面向对象程序设计（Java）》第11周学习总结

201771010102 常惠琢《2018面向对象程序设计（Java）》第11周学习总结