1.第二题 已知有十六支男子足球队参加2008 北京奥运会。写一个程序，把这16 支球队随机分为4 个组。采用List集合和随机数
2008 北京奥运会男足参赛国家：
科特迪瓦，阿根廷，澳大利亚，塞尔维亚，荷兰，尼日利亚、日本，美国，中国，新西 兰，巴西，比利时，韩国，喀麦隆，洪都拉斯，意大利
提示：分配一个，删除一个
package wudil;
import java.util.*;
/**
* Created by ttc on 18-1-10.
*/
public class WorldCupGroup {
public static void main(String[] args) {
Map> groupNum2Countrys = new HashMap<>();
List stringList = new ArrayList<>();
String strCountrys = "科特迪瓦，阿根廷，澳大利亚，塞尔维亚，荷兰，尼日利亚，日本，美国，中国，新西兰，巴西，比利时，韩国，喀麦隆，洪都拉斯，意大利";
String[] countrys = strCountrys.split("，");
for (String str : countrys) {
stringList.add(str);
}
for (int j = 0; j < 4; j++) {
List lstGroup = new ArrayList<>();
for (int i = 0; i < 4; i++) {
Random random = new Random();
int index = random.nextInt(stringList.size());
String selectCountry = stringList.get(index);
lstGroup.add(selectCountry);
stringList.remove(selectCountry);
}
groupNum2Countrys.put(j + 1, lstGroup);
}
for (Integer integer : groupNum2Countrys.keySet()) {
System.out.println("第" + integer + "组");
List lstCountrys = groupNum2Countrys.get(integer);
for (String str : lstCountrys) {
System.out.print(str + "\t");
{
System.out.println();
}
// System.out.println();
}
}
}
}
2.用文件夹形式猜出文件夹里面有多少个单词？
首先在e盘建立一个words.txt文件，在里面把单词放在里面。开始运行
package exprerans;
import java.util.Random;
import java.util.Scanner;
/**
* Created by ttc on 18-1-5.
*/
public class Guessworld {
public static void main(String[] args) {
String[] worlds = {"extends", "interface", "abstract", "implements", "throw", "orange", "student"};
Random random = new Random();
int index = random.nextInt(worlds.length);
// System.out.println(worlds[index]);
char[] world = new char[worlds[index].length()];
for (int i = 0; i < world.length; i++) {
world[i] = '-';
System.out.print(world[i]);
}
Scanner scanner = new Scanner(System.in);
int time = 5;
Guesstext guesstext = new Guesstext();
while (true) {
System.out.println();
char userg = scanner.next().charAt(0);
int num = worlds[index].indexOf(userg);
if (num < 0) {
time--;
if (time == 0) {
break;
}
System.out.println("还剩" + time + "次机会");
guesstext.src(world);
} else {
for (int i = 0; i < world.length; i++) {
if (userg == worlds[index].charAt(i)) {
world[i] = userg;
}
}
guesstext.src(world);
System.out.println();
}
String sre = String.valueOf(world);
if (!sre.contains("-")) {
break;
}
}
if (time > 0) {
System.out.println("你赢了!");
} else {
System.out.println("你输了");
System.out.println(worlds[index]);
}
}
}
练习3. 统计某个文件夹下所有java文件代码行数之和。查一共有多少代码
public class CodeLinesCount {
public static int countJavaFileLines(String strFileName) throws IOException {
FileReader fileReader = new FileReader("e:/mycode/" + strFileName);
BufferedReader bufferedReader = new BufferedReader(fileReader);
int count = 0;
String strLine = bufferedReader.readLine();
while (strLine != null)
{
count++;
strLine = bufferedReader.readLine();
}
return count;
}
public static void main(String[] args) throws IOException {
File file = new File("e:/mycode/");
File[] files = file.listFiles();
int totalCount = 0;
for(File file1 : files)
{
System.out.println(file1.getName());
int count = countJavaFileLines(file1.getName());
totalCount += count;
}
// int count = countJavaFileLines("MyGuessWord.java");
System.out.println(totalCount);
}
}
4.写个程序读取以下学生信息文件，计算出每个学生总分，平均分，名次，写入到一个新文件中
学号 姓名 语文 数学 英语 平均值 总值 排序
1 李守东 83 73 75
2 徐贤坤 58 58 87
3 钱云宋 41 86 90
4 陈平 83 43 65
5 金荣权 93 88 63
6 陈如棉 99 93 43
7 章可可 98 62 72
8 陈伟奔 87 43 76
9 张如祥 69 58 78
10 丁尚游 80 56 57
11 林宏旦 91 90 76
12 曾上腾 100 96 54
13 谢作品 82 100 55
14 温从卫 73 46 101
15 李明察 81 41 75
16 彭鸿威 46 46 89
17 翁文秀 57 43 58
18 陈家伟 63 58 98
19 温正考 100 64 57
20 周文湘 50 50 79
21 吴杰 65 65 83
22 赖登城 60 79 53
23 聂树露 51 76 45
24 张雅琴 68 95 56
25 曾瑞约 88 63 58
26 王志强 96 79 78
27 徐贤所 66 46 74
28 陈祥枭 82 96 91
29 温婷婷 41 73 96
30 应孔余 66 81 71
31 宋成取 71 68 62
32 黄益省 65 56 43
33 陈思文 55 100 44
34 上官福新 64 62 70
35 钟国横 49 69 56
36 林型涨 78 73 50
需要生成的文件
学号 姓名 语文 数学 英语 平均值 总值 排序
1 李守东 83 73 75 77 231 9
2 徐贤坤 58 58 87 67 203 21
3 钱云宋 41 86 90 72 217 15
4 陈平 83 43 65 63 191 29
5 金荣权 93 88 63 81 244 5
6 陈如棉 99 93 43 78 235 7
7 章可可 98 62 72 77 232 8
8 陈伟奔 87 43 76 68 206 19
9 张如祥 69 58 78 68 205 20
10 丁尚游 80 56 57 64 193 27
11 林宏旦 91 90 76 85 257 2
12 曾上腾 100 96 54 83 250 4
13 谢作品 82 100 55 79 237 6
14 温从卫 73 46 101 73 220 11
15 李明察 81 41 75 65 197 25
16 彭鸿威 46 46 89 60 181 31
17 翁文秀 57 43 58 52 158 36
18 陈家伟 63 58 98 73 219 12
19 温正考 100 64 57 73 221 10
20 周文湘 50 50 79 59 179 32
21 吴杰 65 65 83 71 213 16
22 赖登城 60 79 53 64 192 28
23 聂树露 51 76 45 57 172 34
24 张雅琴 68 95 56 73 219 13
25 曾瑞约 88 63 58 69 209 18
26 王志强 96 79 78 84 253 3
27 徐贤所 66 46 74 62 186 30
28 陈祥枭 82 96 91 89 269 1
29 温婷婷 41 73 96 70 210 17
30 应孔余 66 81 71 72 218 14
31 宋成取 71 68 62 67 201 22
32 黄益省 65 56 43 54 164 35
33 陈思文 55 100 44 66 199 24
34 上官新 64 62 70 65 196 26
35 钟国横 49 69 56 58 174 33
36 林型涨 78 73 50 67 201 23
代码：
学生类：
package com.company;
public class Student implements Comparable {
private int sno;
private String name;
private int chinese_score;
private int math_score;
private int eng_score;
private int avg_score;
private int total_score;
public int getEng_score() {
return eng_score;
}
public void setEng_score(int eng_score) {
this.eng_score = eng_score;
}
public int getSno() {
return sno;
}
public void setSno(int sno) {
this.sno = sno;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getChinese_score() {
return chinese_score;
}
public void setChinese_score(int chinese_score) {
this.chinese_score = chinese_score;
}
public int getMath_score() {
return math_score;
}
public void setMath_score(int math_score) {
this.math_score = math_score;
}
public int getAvg_score() {
return avg_score;
}
public void setAvg_score(int avg_score) {
this.avg_score = avg_score;
}
public int getTotal_score() {
return total_score;
}
public void setTotal_score(int total_score) {
this.total_score = total_score;
}
@Override
public String toString() {
return "Student{" +
"sno=" + sno +
", name='" + name + '\'' +
", chinese_score=" + chinese_score +
", math_score=" + math_score +
", eng_score=" + eng_score +
", avg_score=" + avg_score +
", total_score=" + total_score +
'}';
}
@Override
public int compareTo(Object o) {
Student student = (Student)o;
// if(student.getSno() < this.getSno())
// {
// return 5;
// }
// else if(student.getSno() > this.getSno())
// {
// return -9;
// }
// else
// {
// return 0;
// }
// return this.getName().compareTo(student.getName());//打算按学生姓名排序
// return this.getSno() - student.getSno();//打算按学生学号排序
return student.getTotal_score() - this.getTotal_score();//打算按学生总分排序
}
}
主类：
package com.company;
import java.io.*;
import java.util.*;
/**
* Created by ttc on 2018/1/15.
*/
// 学号 姓名 语文 数学 英语 平均值 总值 排序
// 1 李守东 83 73 75
// 2 徐贤坤 58 58 87
// 3 钱云宋 41 86 90
// 4 陈平 83 43 65
// 5 金荣权 93 88 63
public class ComputeStudent {
public static void main(String[] args) throws IOException {
FileReader fileReader = new FileReader("e:/student_score.txt");
BufferedReader bufferedReader = new BufferedReader(fileReader);
String strStudentInfo = bufferedReader.readLine();//跳过头部
List studentList = new ArrayList<>();
strStudentInfo = bufferedReader.readLine();
while(strStudentInfo != null)
{
String[] strings = strStudentInfo.split(" ");
List stringList = new ArrayList();//保存的是一个学生的学号，姓名，三科成绩
for(String str : strings)
{
if(!str.equals(""))
{
stringList.add(str);
}
}
//创建学生对象
Student student = new Student();
int sno = Integer.parseInt(stringList.get(0));
student.setSno(sno);
student.setName(stringList.get(1));
int china_score = Integer.parseInt(stringList.get(2));
student.setChinese_score(china_score);
int math_score = Integer.parseInt(stringList.get(3));
student.setMath_score(math_score);
int eng_score = Integer.parseInt(stringList.get(4));
student.setEng_score(eng_score);
student.setTotal_score(china_score+math_score+eng_score);
student.setAvg_score((china_score+math_score+eng_score)/3);
studentList.add(student);
strStudentInfo = bufferedReader.readLine();
}
System.out.println(strStudentInfo);
FileWriter fileWriter = new FileWriter("e:/student_score_new.txt");
BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
bufferedWriter.write("学号\t姓名\t语文\t数学\t英语\t平均值\t总值\t排序");
bufferedWriter.newLine();
List studentListOld = new ArrayList<>();
studentListOld.addAll(studentList);//studentListOld里学生是按照学号排序
Collections.sort(studentList);//studentList里学生是按照成绩排序
//保存每个学生的名字和排名的键值对
Map mapName2Rank = new HashMap<>();
int index = 1;
for(Student student : studentList)
{
mapName2Rank.put(student.getName(), index++);
}
//遍历list，将list里的每一个student对象写入到文件中
for(Student student : studentListOld)
{
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(student.getSno());
stringBuilder.append("\t");
stringBuilder.append(student.getName());
stringBuilder.append("\t");
stringBuilder.append(student.getChinese_score());
stringBuilder.append("\t");
stringBuilder.append(student.getMath_score());
stringBuilder.append("\t");
stringBuilder.append(student.getEng_score());
stringBuilder.append("\t");
stringBuilder.append(student.getAvg_score());
stringBuilder.append("\t");
stringBuilder.append(student.getTotal_score());
stringBuilder.append("\t");
String strStudentName = student.getName();
int rank = mapName2Rank.get(strStudentName);//拿到了该名学生的名次
stringBuilder.append(rank);
stringBuilder.append("\t");
bufferedWriter.write(stringBuilder.toString());
bufferedWriter.newLine();
}
bufferedWriter.flush();
fileReader.close();
fileWriter.close();
bufferedReader.close();
bufferedWriter.close();
}
}
5.打印一个日历本!
package com.company;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* Created by ttc on 2018/1/16.
*/
public class CalendarDemo2 {
public static void main(String[] args) throws ParseException {
//求出该日期对应的月份一共有多少天
//求出该日期对应的月份，第一天是星期几
String strDate = "2017-09-23";
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
Date date = simpleDateFormat.parse(strDate);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
int day_counts = calendar.getActualMaximum(Calendar.DATE);//求出该日期对应的月份一共有多少天
//获得今天是第几天
int day = calendar.get(Calendar.DATE);
//将日历对象设置成本月的第一天
calendar.set(Calendar.DATE,1);//2018-01-16
int day_of_week = calendar.get(Calendar.DAY_OF_WEEK);
// System.out.println(day_of_week);////求出该日期对应的月份，第一天是星期几
int[] array = new int[6*7];
for(int i = 1; i <= day_counts; i++)
{
array[day_of_week - 1 + i - 1] = i;
}
System.out.print("日\t一\t二\t三\t四\t五\t六");
System.out.println();
for(int i = 0; i < array.length; i++)
{
if(array[i] == 0)
{
System.out.print(" ");
}
else
{
if(array[i] == day)
{
System.out.print("*");
}
System.out.print(array[i]);
}
System.out.print("\t");
if((i+1)%7==0)
{
System.out.println();
}
}
}
}
日历简单一些改了一行代码
package com.company;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* Created by ttc on 2018/1/16.
*/
public class CalendarDemo2 {
public static void main(String[] args) throws ParseException {
//求出该日期对应的月份一共有多少天
//求出该日期对应的月份，第一天是星期几
String strDate = "2017-09-23";
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
Date date = simpleDateFormat.parse(strDate);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
int day_counts = calendar.getActualMaximum(Calendar.DATE);//求出该日期对应的月份一共有多少天
//获得今天是第几天
int day = calendar.get(Calendar.DATE);
//将日历对象设置成本月的第一天
calendar.set(Calendar.DATE,1);//2017-08-01
int day_of_week = calendar.get(Calendar.DAY_OF_WEEK);
// System.out.println(day_of_week);////求出该日期对应的月份，第一天是星期几
int[] array = new int[6*7];
for(int i = 1; i <= day_counts; i++)
{
array[day_of_week - 1] = i;
day_of_week++;
}
System.out.print("日\t一\t二\t三\t四\t五\t六");
System.out.println();
for(int i = 0; i < array.length; i++)
{
if(array[i] == 0)
{
System.out.print(" ");
}
else
{
if(array[i] == day)
{
System.out.print("*");
}
System.out.print(array[i]);
}
System.out.print("\t");
if((i+1)%7==0)
{
System.out.println();
}
}
}
}
6.java多口链接，制作卖车票
第一个类
package com.company;
import java.util.Calendar;
import java.util.List;
/**
* Created by ttc on 2018/1/17.
*/
public class TestSellTicket {
public static void main(String[] args) throws InterruptedException {
System.out.println(Thread.currentThread().getName()+"开始执行");
WindowThread windowThread = new WindowThread();
windowThread.setName("A窗口");
windowThread.start();
WindowThread windowThread2 = new WindowThread();
windowThread2.setName("B窗口");
windowThread2.start();
WindowThread windowThread3 = new WindowThread();
windowThread3.setName("C窗口");
windowThread3.start();
windowThread.join();
windowThread2.join();
windowThread3.join();
System.out.println(Thread.currentThread().getName()+"停止执行");
// System.out.println(Thread.currentThread().getName()+"开始执行");
// WindowRunnable windowRunnable = new WindowRunnable();
// Thread thread1 = new Thread(windowRunnable);
// thread1.setPriority(Thread.MAX_PRIORITY);
// Thread thread2 = new Thread(windowRunnable);
// thread2.setPriority(Thread.MIN_PRIORITY);
// Thread thread3 = new Thread(windowRunnable);
// thread3.setPriority(Thread.MIN_PRIORITY);
// thread1.start();
// thread2.start();
// thread3.start();
}
}
第二个类
package com.company;
/**
* Created by ttc on 2018/1/17.
*/
public class WindowThread extends Thread {
int ticket_count = 100;
@Override
public void run()
{
while (true)
{
if(ticket_count > 0)
{
System.out.println(Thread.currentThread().getName() + "卖出了" + ticket_count);
ticket_count--;
try {
Thread.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
else
{
break;
}
}
}
}