孔维滢201771010110 / 冯志霞《面向对象程序设计（java）》第十一周学习总结

理论知识部分

    1.数据结构：一般将数据结构分为两大类：线性数据结构和非线性数据结构。

                         线性数据结构：线性表、栈、队列、串、数组和文件。

                         非线性数据结构：树和图。

    2.JAVA的集合框架：

       JAVA的集合框架实现对各种数据结构的封装，以降低对数据管理与处理的难度。所谓框架就是一个类库的集合，框架中包含很多 超类，编程者创建这些超类的子类可较方便的设 计设计程序所需的类。

       集合(Collection或称为容器)是一种包含多个元素 并提供对所包含元素操作方法的类，其包含的元 素可以由同一类型的对象组成，也可以由不同类 型的对象组成。

    3.集合类：

       集合类的作用：Java的集合类提供了一些基本数据结构的支持。例如Vector、Hashtable、Stack等。

       集合类的使用：Java的集合类包含在java.util包中。 

       集合类的特点：只容纳对象；

                                集合类容纳的对象都是Object类的实例，一旦 把一个对象置入集合类中，它的类信息将丢失 ，这样设计的目的是为了集合类的通用性。

    4.Vector类：

       Vector类类似长度可变的数组。

       Vector中只能存放对象。

       Vector的元素通过下标进行访问。

       Vector类关键属性：capacity表示集合多能容纳的元素个数。

                                       capacityIncrement表示每次增加多少容量。

                                       size表示集合当前元素个数。

    5.Stack类：

       Stack类是Vector的子类。

       Stack类描述堆栈数据结构，即LIFO。

    6.Hashtable类：

       Hashtable通过键来查找元素。

       Hashtable用散列码（hashcode）来确定键。所 有对象都有一个散列码，可以通过Object类的 hashCode()方法获得。

    7.集合框架中的基本接口：

       Collection：集合层次中的根接口，JDK未提供这个 接口的直接实现类。

       Set：不能包含重复的元素。对象可能不是按存放的 次序存放，也就是说不能像数组一样按索引的方式进 行访问，SortedSet是一个按照升序排列元素的Set。

       List：是一个有序的集合，可以包含重复的元素。提 供了按索引访问的方式。

       Map：包含了key-value对。Map不能包含重复的key 。

       SortedMap是一个按照升序排列key的Map。

实验部分：

实验1：

测试程序1：

示例程序1

import java.util.Vector;//自动增长的对象数组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();//强制类型转化}
}

出现错误，dog类不能转换成cat类，修改程序：

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++) {if (cats.elementAt(i) instanceof Cat)//加入判断语句，判断是否能进行强制类型转换((Cat) cats.elementAt(i)).print();//如果能进行强制类型转换，输出为Catelse {((Dog) cats.elementAt(i)).print();//不能则输出dog}}}
}

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]);//元素进栈System.out.println(stk);System.out.println("element 2=" + stk.elementAt(2));while (!stk.empty())System.out.println(stk.pop());//元素出栈}
}

示例程序3：

import java.util.*;class Counter {int i = 1;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19的20个整型随机数if (ht.containsKey(r))//判断r是否是哈希表中元素的键值((Counter) ht.get(r)).i++;elseht.put(r, new Counter());}System.out.println(ht);}
}

测试程序2：

import java.util.*;public class ArrayListDemo {public static void main(String[] argv) {ArrayList al = new ArrayList();// //在ArrayList中添加多个元素al.add(new Integer(11));al.add(new Integer(12));al.add(new Integer(13));al.add(new String("hello"));// 用循环语句打印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());//迭代对象生成器l.add("Hello");l.add("zhangsan");ListIterator li = l.listIterator(0);//通过迭代器生成对象产生方法hasNext返回while (li.hasNext())System.out.println(li.next());if (l.indexOf("Hello") < 0)   //判断元素是否在集合当中，如果是，返回一个大于0的值，如果不是，返回负值System.err.println("Lookup does not work");elseSystem.err.println("Lookup works");}
}

package linkedList;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){List a = new LinkedList<>();//泛型创建a链表a.add("Amy");a.add("Carl");a.add("Erica");List b = new LinkedList<>();//泛型创建b链表b.add("Bob");b.add("Doug");b.add("Frances");b.add("Gloria");// //合并a和b中的单词ListIterator aIter = a.listIterator();Iterator 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(); // 跳到第一个元素
         if (bIter.hasNext()){bIter.next(); // 跳到下一个元素
            bIter.remove(); // 删除该元素
         }}System.out.println(b);// 批量操作: 删除从b到a的所有单词a.removeAll(b);System.out.println(a);}
}

测试程序3：

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"); // DUPLICATEh.add("Three");Iterator it = h.iterator();while (it.hasNext()) {System.out.println(it.next());}}
}

package set;import java.util.*;/*** This program uses a set to print all unique words in System.in.* @version 1.12 2015-06-21* @author Cay Horstmann*/
public class SetTest
{public static void main(String[] args){Set words = new HashSet<>(); // HashSet 实现 Setlong totalTime = 0;try (Scanner in = new Scanner(System.in)){while (in.hasNext()){String word = in.next();long callTime = System.currentTimeMillis();words.add(word);callTime = System.currentTimeMillis() - callTime;totalTime += callTime;}}Iterator iter = words.iterator();//元素排序for (int i = 1; i <= 20 && iter.hasNext(); i++)System.out.println(iter.next());System.out.println(". . .");System.out.println(words.size() + " distinct words. " + totalTime + " milliseconds.");}
}

TreeSetTest.java

package treeSet;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 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 sortByDescription = new TreeSet<>(Comparator.comparing(Item::getDescription));//自定义类对象存入TreeSet排序sortByDescription.addAll(parts);System.out.println(sortByDescription);}
}

　　Item.java

package treeSet;import java.util.*;/*** An item with a description and a part number.*/
public class Item implements Comparable
{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){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){int diff = Integer.compare(partNumber, other.partNumber);return diff != 0 ? diff : description.compareTo(other.description);}
}

测试程序4：

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);}
}

MapTest.java

package map;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
{public static void main(String[] args){Map 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"));// 表里所有条目staff.forEach((k, v) -> System.out.println("key=" + k + ", value=" + v));}
}

　　Employee.java

package map;/*** A minimalist employee class for testing purposes.*/
public class Employee
{private String name;private double salary;/*** Constructs an employee with $0 salary.* @param n the employee name*/public Employee(String name){this.name = name;salary = 0;}public String toString(){return "[name=" + name + ", salary=" + salary + "]";}
}

实验2：结对编程练习：

 本次实验结对编程合作伙伴：冯志霞

实验九编程练习1：

package fzx;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.Scanner;public class A{private static ArrayList 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.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();Test student = new Test();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) {System.out.println("学生信息文件找不到");e.printStackTrace();} catch (IOException e) {System.out.println("学生信息文件读取错误");e.printStackTrace();}boolean isTrue = true;while (isTrue) {System.out.println("1:字典排序");System.out.println("2:输出年龄最大和年龄最小的人");System.out.println("3:寻找老乡");System.out.println("4:寻找年龄相近的人");System.out.println("5:退出");String m = scanner.next();switch (m) {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;imax){max=j; k1=i;}if(j

package fzx;public  class Test implements Comparable {private String name;private String number ;private String sex ;private int age;private String province;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getnumber() {return number;}public void setnumber(String number) {this.number = number;}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 getprovince() {return province;}public void setprovince(String province) {this.province=province ;}public int compareTo(Test o) {return this.name.compareTo(o.getName());}public String toString() {return  name+"\t"+sex+"\t"+age+"\t"+number+"\t"+province+"\n";}}

package 算术;import java.util.Random;
import java.util.Scanner;import java.io.FileNotFoundException;import java.io.PrintWriter;public class Main{public static void main(String[] args){yunsuan counter=new yunsuan();//与其它类建立联系PrintWriter out=null;try {out=new PrintWriter("D:/text.txt");//将文件里的内容读入到D盘名叫text的文件中}catch(FileNotFoundException e) {System.out.println("文件找不到");e.printStackTrace();}int sum=0;for(int i=0;i<10;i++){int a=new Random().nextInt(100);int b=new Random().nextInt(100);Scanner in=new Scanner(System.in);//in.close();switch((int)(Math.random()*4)){case 0:System.out.println( ""+a+"+"+b+"=");int c1 = in.nextInt();out.println(a+"+"+b+"="+c1);if (c1 == counter.plus(a, b)) {sum += 10;System.out.println("答案正确");}else {System.out.println("答案错误");}break ;case 1:if(a

package 算术;public class yunsuan {private T a;private T b;public void yunsaun(){a=null;b=null;}public void yunsuan(T a,T b){this.a=a;this.b=b;}public int plus(int a,int b){return a+b;}public int minus(int a,int b){return a-b;}public int multiply(int a,int b){return a*b;}public int divide(int a,int b){if(b!=0  && a%b==0)return a/b;elsereturn 0;}}

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.Scanner;public class A{private static ArrayList 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.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();Test student = new Test();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) {System.out.println("学生信息文件找不到");e.printStackTrace();} catch (IOException e) {System.out.println("学生信息文件读取错误");e.printStackTrace();}boolean isTrue = true;while (isTrue) {System.out.println("1:字典排序");System.out.println("2:输出年龄最大和年龄最小的人");System.out.println("3:寻找老乡");System.out.println("4:寻找年龄相近的人");System.out.println("5:退出");String m = scanner.next();switch (m) {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;imax){max=j; k1=i;}if(j

public  class Test implements Comparable {private String name;private String number ;private String sex ;private int age;private String province;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getnumber() {return number;}public void setnumber(String number) {this.number = number;}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 getprovince() {return province;}public void setprovince(String province) {this.province=province ;}public int compareTo(Test o) {return this.name.compareTo(o.getName());}public String toString() {return  name+"\t"+sex+"\t"+age+"\t"+number+"\t"+province+"\n";}}

package 算术;import java.util.Random;
import java.util.Scanner;import java.io.FileNotFoundException;import java.io.PrintWriter;public class Main{public static void main(String[] args){yunsuan counter=new yunsuan();//与其它类建立联系PrintWriter out=null;try {out=new PrintWriter("D:/text.txt");//将文件里的内容读入到D盘名叫text的文件中}catch(FileNotFoundException e) {System.out.println("文件找不到");e.printStackTrace();}int sum=0;for(int i=0;i<10;i++){int a=new Random().nextInt(100);int b=new Random().nextInt(100);Scanner in=new Scanner(System.in);//in.close();switch((int)(Math.random()*4)){case 0:System.out.println( ""+a+"+"+b+"=");int c1 = in.nextInt();out.println(a+"+"+b+"="+c1);if (c1 == counter.plus(a, b)) {sum += 10;System.out.println("答案正确");}else {System.out.println("答案错误");}break ;case 1:if(a

package 算术;public class yunsuan {private T a;private T b;public void yunsaun(){a=null;b=null;}public void yunsuan(T a,T b){this.a=a;this.b=b;}public int plus(int a,int b){return a+b;}public int minus(int a,int b){return a-b;}public int multiply(int a,int b){return a*b;}public int divide(int a,int b){if(b!=0  && a%b==0)return a/b;elsereturn 0;}}

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