題目1:
HashMap集合存儲學生對象并遍歷。

需求:
創建一個HashMap集合，鍵是學生對象(Student)，值是居住地(String)。存儲多個鍵值對象，并遍歷。

要求:
保證鍵的唯一性：如果學生對象的成員變量值相同，我們就認為是同一個對象。

代碼如下:

package HashMapPrintPack02;public class Student {private String name;private int age;public Student() {}public Student(String name, int age) {this.name = name;this.age = age;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}@Overridepublic boolean equals(Object o) {if (this == o) return true;if (o == null || getClass() != o.getClass()) return false;Student student = (Student) o;if (age != student.age) return false;return name != null ? name.equals(student.name) : student.name == null;}@Overridepublic int hashCode() {int result = name != null ? name.hashCode() : 0;result = 31 * result + age;return result;} } package HashMapPrintPack02;import java.util.HashMap; import java.util.Set;public class HashMapDemo {public static void main(String[] args){HashMap<Student,String> hs = new HashMap<Student,String>();Student s1 = new Student("Tom",30);Student s2 = new Student("Jack",28);Student s3 = new Student("Lily",17);Student s4 = new Student("Tom",30);hs.put(s1,"西安");hs.put(s2,"北京");hs.put(s3,"上海");hs.put(s4,"深圳");Set<Student> keySet = hs.keySet();for (Student key:keySet){String value = hs.get(key);System.out.println(key.getName()+","+key.getAge()+","+value);}}}

題目2:
ArrayList集合存儲HashMap元素并遍歷。

需求:
創建一個ArrayList集合，存儲三個元素，每一個元素都是HashMap，每一個HashMap的鍵和值都是String，并遍歷。

代碼如下:

package ArrayListAndHashMapPack01;import java.util.ArrayList; import java.util.HashMap; import java.util.Set;public class ArrayListIncludeHashMapDemo {public static void main(String[] args){ArrayList<HashMap<String,String>> array = new ArrayList<HashMap<String, String>>();HashMap<String,String> hm1 = new HashMap<String,String>();hm1.put("Tom","Jack");hm1.put("Bom","Lily");array.add(hm1);HashMap<String,String> hm2 = new HashMap<String,String>();hm1.put("小明","小紅");hm1.put("小蘭","小綠");array.add(hm2);HashMap<String,String> hm3 = new HashMap<String,String>();hm1.put("Mike","Zliy");hm1.put("Bo","Db");array.add(hm3);for(HashMap<String,String> hm:array){Set<String> keySet = hm.keySet();for (String key:keySet){String value = hm.get(key);System.out.println(key+","+value);}}} }

題目3:
HashMap集合存儲ArrayList元素并遍歷。

需求:
創建一個HashMap集合，存儲三個鍵值對元素，每一個鍵值對元素的鍵是String，值是ArrayList，每一個ArrayList的元素是String，并遍歷。

代碼如下:

package HashMapIncludeArrayListPack;import java.util.ArrayList; import java.util.HashMap; import java.util.Set;public class HashMapIncludeArrayListDemo {public static void main(String[] args){HashMap<String, ArrayList<String>> hm = new HashMap<String,ArrayList<String>>();ArrayList<String> sgyy = new ArrayList<String>();sgyy.add("趙云");sgyy.add("劉備");hm.put("三國演義",sgyy);ArrayList<String> xyj = new ArrayList<String>();xyj.add("唐僧");xyj.add("猴哥");hm.put("西游記",xyj);ArrayList<String> hlm = new ArrayList<String>();hlm.add("賈寶玉");hlm.add("林黛玉");hm.put("紅樓夢",hlm);Set<String> keySet = hm.keySet();for (String key:keySet){System.out.println(key);ArrayList<String> value = hm.get(key);for (String s:value){System.out.println("\t"+s);}}}}

題目4:
統計字符串中每個字符串出現的次數。

需求:
鍵盤錄入一個字符串，要求統計字符串中每個字符串出現的次數。
舉例：
鍵盤錄入"aababcabcdabcde",在控制臺輸出:“a(5)b(4)c(3)d(2)e(1)”

代碼如下:

package CountStringNumPack;import java.util.HashMap; import java.util.Scanner; import java.util.Set;public class HashMapDemp {public static void main(String[] args){Scanner sc = new Scanner(System.in);System.out.println("請輸入一個字符串");String line = sc.nextLine();HashMap<Character,Integer> hm = new HashMap<Character,Integer>();for (int i = 0;i<line.length();i++){char key = line.charAt(i);Integer value = hm.get(key);if (value==null){hm.put(key,1);}else {value++;hm.put(key, value);}}StringBuilder sb = new StringBuilder();Set<Character> keySet = hm.keySet();for (Character key:keySet){Integer value = hm.get(key);sb.append(key).append("(").append(value).append(")");}String ans = sb.toString();System.out.println(ans);}} package CountStringNumPack;import java.util.Scanner; import java.util.Set; import java.util.TreeMap;public class HashMapDemp {public static void main(String[] args){Scanner sc = new Scanner(System.in);System.out.println("請輸入一個字符串");String line = sc.nextLine();TreeMap<Character,Integer> hm = new TreeMap<Character,Integer>();for (int i = 0;i<line.length();i++){char key = line.charAt(i);Integer value = hm.get(key);if (value==null){hm.put(key,1);}else {value++;hm.put(key, value);}}StringBuilder sb = new StringBuilder();Set<Character> keySet = hm.keySet();for (Character key:keySet){Integer value = hm.get(key);sb.append(key).append("(").append(value).append(")");}String ans = sb.toString();System.out.println(ans);}}

題目5:
ArrayList存儲學生對象并排序。

需求:
ArrayList存儲學生對象，使用Collections對ArrayList進行排序。
要求:
按照年齡從小到大排序，年齡相同時，按照姓名的字母順序排序。

代碼如下:

package CollectionsDemo02;public class Student {private String name;private int age;public Student() {}public Student(String name, int age) {this.name = name;this.age = age;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}} package CollectionsDemo02;import java.util.ArrayList; import java.util.Collections; import java.util.Comparator;public class CollectionsDemo02 {public static void main(String[] args){ArrayList<Student> array = new ArrayList<Student>();Student s1 = new Student("Tom",18);Student s2 = new Student("Jack",20);Student s3 = new Student("Bom",29);Student s4 = new Student("Lily",23);array.add(s1);array.add(s2);array.add(s3);array.add(s4);Collections.sort(array, new Comparator<Student>() {@Overridepublic int compare(Student s1, Student s2) {int num = s1.getAge()-s2.getAge();int num2 = num==0?s1.getName().compareTo(s2.getName()):num;return num2;}});for (Student s:array){System.out.println(s.getName()+","+s.getAge());}} }

題目6:
模擬斗地主。

需求：
通過程序實現斗地主過程中的洗牌，發牌和看牌。

代碼如下：

package PokerPack01;import java.util.ArrayList; import java.util.Collections;public class PokerDemo01 {public static void main(String[] args) {ArrayList<String> array = new ArrayList<String>();String[] colors = {"◆", "?", "?", "?"};String[] numbers = {"2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K", "A"};for (String color : colors) {for (String number:numbers){array.add(color+number);}}array.add("大王") ;array.add("小王");Collections.shuffle(array);// System.out.println(array);ArrayList<String> tomArray = new ArrayList<String>();ArrayList<String> jackArray = new ArrayList<String>();ArrayList<String> bomArray = new ArrayList<String>();ArrayList<String> dpArray = new ArrayList<String>();for (int i = 0;i<array.size();i++){String poker = array.get(i);if (i >= array.size()-3){dpArray.add(poker);}else if (i % 3==0){tomArray.add(poker);}else if (i % 3==1){jackArray.add(poker);}else if (i % 3==2){bomArray.add(poker);}}lookPoker("Tom",tomArray);lookPoker("Jack",jackArray);lookPoker("Bom",bomArray);}public static void lookPoker(String name,ArrayList<String> array){System.out.println(name+"的牌是:");for (String poker:array){System.out.print(poker+" ");}System.out.println();} }

題目7：
模擬斗地主2.0

需求:
通過程序實現斗地主過程中的洗牌，發牌和看牌。
要求:
對牌進行排序。

代碼如下:
有時間寫!!!

題目8(遞歸):
有一對兔子，從出生后第3個月起每個月都生一對兔子，小兔子長到第三個月后每個月又生一對兔子，假如兔子都不死，問第二十個月的兔子對數為多少？

代碼如下:

package DiGuiPack;public class DiGuDemo01 {public static void main(String[] args){int ans = f(20);System.out.println(ans);}public static int f(int n){if (n==1 || n==2) return 1;else return f(n-1)+f(n-2);} }

題目9:

需求:
用遞歸求5的階乘，并把結果在控制臺輸出。

代碼如下:

package DiGuiPack;public class DiGuDemo01 {public static void main(String[] args){int ans = f(5);System.out.println(ans);}public static int f(int n){if (n==1) return 1;else return n*f(n-1);}}

題目10:
遍歷目錄。

需求:
給定一個路徑(D:\JavaDemo),請通過遞歸完成遍歷該目錄下的所有內容，并把所有文件的絕對路徑輸出在控制臺。

代碼如下:

package DiGuiPack;import java.io.File;public class DiGuiDemo02 {public static void main(String[] args){File srcfile = new File("D:\\JavaDemo");getAllFilePath(srcfile);}public static void getAllFilePath(File srcFile){File[] fileArray = srcFile.listFiles();if (fileArray!=null){for (File file:fileArray){if (file.isDirectory()){getAllFilePath(file);}else{System.out.println(file.getAbsolutePath());}}}}}

題目11:
復制文本文件。

需求:
把“D:\JavaDemo\java.txt”復制到模塊目錄下的"窗里窗外.txt"

代碼如下:

package InstreamPack;import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException;public class CopyTxtDemo {public static void main(String[] args) throws IOException {FileInputStream fis = new FileInputStream("D:\\JavaDemo\\java.txt");FileOutputStream fos = new FileOutputStream("D:\\JavaDemo\\窗里窗外.txt");int by;while((by = fis.read())!=-1){fos.write(by);}fis.close();fos.close();}}

題目12:
復制圖片。

需求:
把"D:\JavaDemo\luf.jpg"，復制到某個目錄。

代碼如下:

package InstreamPack;import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException;public class FileInputStreamDemo02 {public static void main(String[] args) throws IOException {FileInputStream fis = new FileInputStream("D:\\JavaDemo\\luf.jpg");FileOutputStream fos = new FileOutputStream("D:\\JavaDemo\\tyc.jpg");byte[] bys = new byte[1024];int len;while((len=fis.read(bys))!=-1){fos.write(bys,0,len);}fis.close();fos.close();} }

題目13:
復制視頻。

需求:
把"D:\JavaDemo\字節流復制圖片.avi",復制到模塊目錄下的"字節流復制圖片.avi"

代碼如下:

題目14：

復制Java文件。

需求:把“D:\JavaDemo\ArgsDemo01.java”復制一份。

代碼如下:

package CopyJavaPack01;import java.io.*;public class CopyJavaDemo01 {public static void main(String[] args) throws IOException {InputStreamReader isr = new InputStreamReader(new FileInputStream("D:\\JavaDemo\\ArgsDemo01.java"));OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream("D:\\JavaDemo\\hello.java"));int ch;while((ch = isr.read())!=-1){osw.write(ch);}osw.close();isr.close();} } package CopyJavaPack01;import java.io.*;public class CopyJavaDemo01 {public static void main(String[] args) throws IOException {InputStreamReader isr = new InputStreamReader(new FileInputStream("D:\\JavaDemo\\ArgsDemo01.java"));OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream("D:\\JavaDemo\\hello.java"));// int ch; // while((ch = isr.read())!=-1) // { // osw.write(ch); // }char[] chs = new char[1024];int len;while((len=isr.read(chs))!=-1){osw.write(chs,0,len);}osw.close();isr.close();} }

題目15:
復制Java文件。

需求:
把“D:\JavaDemo\ArgsDemo01.java”復制一份。

代碼如下:

package CopyJavaPack01;import java.io.FileNotFoundException; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException;public class CopyJavaDemo02 {public static void main(String[] args) throws IOException {FileReader fr = new FileReader("D:\\JavaDemo\\ArgsDemo01.java");FileWriter fw = new FileWriter("D:\\JavaDemo\\hellow02.java");int ch;while((ch=fr.read())!=-1){fw.write(ch);}fw.close();fr.close();}} package CopyJavaPack01;import java.io.FileNotFoundException; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException;public class CopyJavaDemo02 {public static void main(String[] args) throws IOException {FileReader fr = new FileReader("D:\\JavaDemo\\ArgsDemo01.java");FileWriter fw = new FileWriter("D:\\JavaDemo\\hellow02.java");// int ch; // while((ch=fr.read())!=-1) // { // fw.write(ch); // }char[]chs = new char[1024];int len;while((len=fr.read(chs))!=-1){fw.write(chs,0,len);}fw.close();fr.close();}}

題目16:
復制Java文件(字符緩沖流改進版)

需求:
把“D:\JavaDemo\hellow02.java”復制一份。

代碼如下:

package CopyJavaPack01;import java.io.*;public class CopyJavaDemo03 {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new FileReader("D:\\JavaDemo\\hellow02.java"));BufferedWriter bw = new BufferedWriter(new FileWriter("D:\\JavaDemo\\hello03.java"));int ch;while((ch=br.read())!=-1){bw.write(ch);}bw.close();br.close();}} package CopyJavaPack01;import java.io.*;public class CopyJavaDemo03 {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new FileReader("D:\\JavaDemo\\hellow02.java"));BufferedWriter bw = new BufferedWriter(new FileWriter("D:\\JavaDemo\\hello03.java"));// int ch; // while((ch=br.read())!=-1) // { // bw.write(ch); // }char [] chs = new char[1024];int len;while((len=br.read(chs))!=-1){bw.write(chs,0,len);}bw.close();br.close();}}

題目17:
復制Java文件(字符緩沖流特有功能改進版)

需求:
把“D:\JavaDemo\hello.java”復制一份。

package CopyJavaPack01;import java.io.*;public class CopyJavaDemo04 {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new FileReader("D:\\JavaDemo\\hello.java"));BufferedWriter bw = new BufferedWriter(new FileWriter("D:\\JavaDemo\\java01.java"));String line;while((line=br.readLine())!=null){System.out.println(line);bw.newLine();bw.flush();}br.close();bw.close();}}

題目18:
集合到文件。

需求:
把ArrayList集合中的字符串數據寫入到文本文件。

要求:
每一個字符串元素作為文件中的一行數據。

代碼如下:

package test22;import java.io.BufferedWriter; import java.io.FileWriter; import java.io.IOException; import java.util.ArrayList;public class ArrayListToTxtDemo {public static void main(String[] args) throws IOException {ArrayList<String> array = new ArrayList<String>();array.add("hello");array.add("world");array.add("java");BufferedWriter bw = new BufferedWriter(new FileWriter("D:\\JavaDemo\\array.txt"));for (String s:array){bw.write(s);bw.newLine();bw.flush();}bw.close();} }

題目19:
文件到集合。

需求:
把文本文件中的數據讀取到集合中，并遍歷集合。

要求:
文件中每一行數據是一個集合元素。

代碼如下:

package test22;import java.io.*; import java.util.ArrayList;public class TxtToArrayListDemo {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new FileReader("D:\\JavaDemo\\array.txt"));ArrayList<String> array = new ArrayList<String>();String line;while((line = br.readLine())!=null){array.add(line);}br.close();for (String s:array){System.out.println(s);}} }

題目20:
點名器。

需求:
我有一個文件里面存儲了班級同學的姓名，每一行姓名占一行，要求通過程序實現隨機點名器。

代碼如下:

package test22;import java.io.BufferedReader; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.util.ArrayList; import java.util.Random;public class CallNameDemo {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new FileReader("D:\\JavaDemo\\array.txt"));ArrayList<String> array = new ArrayList<String>();String line;while((line = br.readLine())!=null){array.add(line);}br.close();Random r = new Random();int idx = r.nextInt(array.size());String name = array.get(idx);System.out.println("幸運兒是:"+name);}}

題目21:
集合到文件(改進版)。

需求:
把ArrayList集合中的字符串數據寫入到文本文件。

要求:
每一個字符串元素作為文件中的一行數據。

格式:
學號，姓名，年齡，居住地

舉例:
001,Tom,24,北京

代碼如下:

package test22;public class Student {private String sid;private String name;private int age;private String address;public Student() {}public Student(String sid, String name, int age, String address) {this.sid = sid;this.name = name;this.age = age;this.address = address;}public String getSid() {return sid;}public void setSid(String sid) {this.sid = sid;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;} } package test22;import java.io.BufferedWriter; import java.io.FileWriter; import java.io.IOException; import java.util.ArrayList;public class ArrayListToFileDemo {public static void main(String[] args) throws IOException {ArrayList<Student> array = new ArrayList<Student>();Student s1 = new Student("001","Tom",20,"北京");Student s2 = new Student("002","Jack",18,"上海");Student s3 = new Student("003","Bom",22,"韶關");Student s4 = new Student("004","Lily",23,"美國");array.add(s1);array.add(s2);array.add(s3);array.add(s4);BufferedWriter bw = new BufferedWriter(new FileWriter("D:\\JavaDemo\\students.txt"));for (Student s:array){StringBuilder sb = new StringBuilder();sb.append(s.getSid()).append(",").append(s.getName()).append(",").append(s.getAge()).append(",").append(s.getAddress());bw.write(sb.toString());bw.newLine();bw.flush();}bw.close();}}

題目22:
文件到集合(改進版)。

需求:
把文本文件中的數據讀取到集合中，并遍歷集合。

要求:
文件中每一行數據是一個集合元素。

舉例:
001,Tom,29,北京

代碼如下:

package test22;public class Student {private String sid;private String name;private int age;private String address;public Student() {}public Student(String sid, String name, int age, String address) {this.sid = sid;this.name = name;this.age = age;this.address = address;}public String getSid() {return sid;}public void setSid(String sid) {this.sid = sid;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;} } package test22;import java.io.BufferedReader; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.util.ArrayList;public class FileToArrayListDemo {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new FileReader("D:\\JavaDemo\\students.txt"));ArrayList<Student> array = new ArrayList<Student>();String line;while((line = br.readLine())!=null){String[] strArray = line.split(",");Student s = new Student();s.setSid(strArray[0]);s.setName(strArray[1]);s.setAge(Integer.parseInt(strArray[2]));s.setAddress(strArray[3]);array.add(s);}br.close();for (Student s:array){System.out.println(s.getSid()+","+s.getName()+","+s.getAge()+","+s.getAddress());}} }

題目23:
集合到文件(數據排序改進版)

需求:
鍵盤錄入5個學生信息(學生，語文成績，數學成績，英語成績)。要求按照成績總分從高到低寫入文本文件。

格式:
姓名，語文成績，數學成績，英語成績

舉例:
Tom,98,99,100

代碼如下:

package ArrayListToFilePack;public class Student {private String name;private int chinese;private int math;private int english;public Student() {}public Student(String name, int chinese, int math, int english) {this.name = name;this.chinese = chinese;this.math = math;this.english = english;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getChinese() {return chinese;}public void setChinese(int chinese) {this.chinese = chinese;}public int getMath() {return math;}public void setMath(int math) {this.math = math;}public int getEnglish() {return english;}public void setEnglish(int english) {this.english = english;}public int getSum(){return chinese+math+english;}} package ArrayListToFilePack;import java.io.BufferedWriter; import java.io.FileWriter; import java.io.IOException; import java.util.Comparator; import java.util.Scanner; import java.util.TreeSet;public class TreeSetToFileDemo {public static void main(String[] args) throws IOException {TreeSet<Student> ts = new TreeSet<Student>(new Comparator<Student>() {@Overridepublic int compare(Student s1, Student s2) {int num1 = s2.getSum()-s1.getSum();int num2 = num1==0? s1.getChinese()- s2.getChinese() :num1;int num3 = num2==0?s1.getMath()-s2.getMath():num2;int num4 = num3==0?s1.getName().compareTo(s2.getName()):num3;return num4;}});for (int i =0;i<5;i++){Scanner sc = new Scanner(System.in);System.out.println("請錄入第"+(i+1)+"個學生信息");System.out.println("name = ");String name = sc.nextLine();System.out.println("語文成績 = ");int chinese = sc.nextInt();System.out.println("數學成績 = ");int math = sc.nextInt();System.out.println("英語成績 = ");int english = sc.nextInt();Student s = new Student();s.setName(name);s.setChinese(chinese);s.setMath(math);s.setEnglish(english);ts.add(s);}BufferedWriter bw = new BufferedWriter(new FileWriter("D:\\JavaDemo\\ts.txt"));for (Student s :ts){StringBuilder sb = new StringBuilder();sb.append(s.getName()).append(",").append(s.getChinese()).append(",").append(s.getMath()).append(",").append(s.getEnglish()).append(",").append(s.getSum());bw.write(sb.toString());bw.newLine();bw.flush();}bw.close();} }

題目24:
復制單級文件夾。

需求:
把"D:\JavaDemo\hello"這個文件夾復制到"D:\JavaDemo02"這個文件夾里。

代碼如下:

package CopyFolderPack;import java.io.*;public class CopyFolderDemo {public static void main(String[] args) throws IOException {File srcFolder = new File("D:\\JavaDemo\\hello");String srcFolderName = srcFolder.getName();File destFolder = new File("D:\\JavaDemo02",srcFolderName);if (!destFolder.exists()){destFolder.mkdir();}File[] listFiles = srcFolder.listFiles();for (File srcFile : listFiles){String srcFileName = srcFile.getName();File destFile = new File(destFolder,srcFileName);copyFile(srcFile,destFile);}}private static void copyFile(File srcFile, File destFile) throws IOException {BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcFile));BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destFile));byte[] bys = new byte[1024];int len;while((len = bis.read())!=-1){bos.write(bys,0,len);}bos.close();bis.close();} }

題目25:
復制多級文件夾。

需求:
把"D:\JavaDemo"復制到"D:\JavaDemo02"這個文件夾里。

代碼如下:

package CopyFolderPack;import java.io.*;public class CopyFoldersDemo {public static void main(String[] args) throws IOException {File srcFile = new File("D:\\JavaDemo");File destFile = new File("D:\\JavaDemo02");copyFolder(srcFile,destFile);}//復制文件夾private static void copyFolder(File srcFile, File destFile) throws IOException {if (srcFile.isDirectory()){String srcFileName = srcFile.getName();File newFolder = new File(destFile,srcFileName);if (!newFolder.exists()){newFolder.mkdir();}File[] fileArray = srcFile.listFiles();for (File file:fileArray){copyFolder(file,newFolder);}}else{File newFile = new File(destFile,srcFile.getName());copyFile(srcFile,newFile);}}private static void copyFile(File srcFile, File destFile) throws IOException {BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcFile));BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destFile));byte[] bys = new byte[1024];int len;while((len = bis.read(bys))!=-1){bos.write(bys,0,len);}bos.close();bis.close();}}

題目26:
復制Java文件(打印流改進版)

需求:
把"D:\JavaDemo\hello.java"復制到"D:\JavaDemo03\java01.java"
。

代碼如下:

package CopyJavaPack02;import java.io.*;public class CopyJavaDemo {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new FileReader("D:\\JavaDemo\\hello.java"));BufferedWriter bw = new BufferedWriter(new FileWriter("D:\\JavaDemo03\\java01.java"));String line;while((line = br.readLine())!=null){bw.write(line);bw.newLine();bw.flush();}bw.close();br.close();} } package CopyJavaPack02;import java.io.*;public class CopyJavaDemo {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new FileReader("D:\\JavaDemo\\hello.java"));PrintWriter bw = new PrintWriter(new FileWriter("D:\\JavaDemo03\\java01.java"),true);String line;while((line = br.readLine())!=null){bw.println(line);}bw.close();br.close();} }

題目27:
游戲次數。

需求:
請寫程序實現猜數字小游戲只能試玩3次，如果還想玩，提示:游戲試玩已結束，想玩請充值。

game.txt:

代碼如下:

在這里插入代碼片package PropertiesPack;import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.util.Properties;public class PropertiesTest {public static void main(String[] args) throws IOException {Properties prop = new Properties();FileReader fr = new FileReader("D:\\JavaDemo\\game.txt");prop.load(fr);fr.close();String count = prop.getProperty("count");int number = Integer.parseInt(count);if (number >= 3){System.out.println("游戲試玩已結束，想玩請充值");}else{GuessNumber.start();number++;prop.setProperty("count",String.valueOf(number));FileWriter fw = new FileWriter("D:\\JavaDemo\\game.txt");prop.store(fw,null);fw.close();}}}

題目28:
賣票。

需求:
某電影院目前正在上映國產大片，共有100張票，而它有3個窗口賣票，請設計一個程序模擬該電影院賣票。

代碼如下：

package SellTicketPack;public class SellTicket implements Runnable{private int tickets = 100;@Overridepublic void run() {while (true) {if (tickets > 0) {System.out.println(Thread.currentThread().getName() + "正在出售第" + tickets + "張票");tickets--;}}}} package SellTicketPack;public class SellTicketDemo {public static void main(String[] args){SellTicket st = new SellTicket();Thread t1 = new Thread(st,"窗口1");Thread t2 = new Thread(st,"窗口2");Thread t3 = new Thread(st,"窗口3");t1.start();t2.start();t3.start();}}

題目29:
賣票問題(進階)。

點擊下方鏈接:

賣票問題(進階)

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