实现注册、登录功能。用户名、密码存储在user_g.txt文件中
1.题目具体要求如下：
/*
程序实现注册、登录功能。用户名、密码存储在user_g.txt文件中。
注册时，要验证“用户名”是否存在，如果存在，则注册失败。
注册成功后，用户可以使用已注册的用户名和密码进行登录。
登录后提示：欢迎xxxx登录系统，然后用户登录后，可以玩“猜数字”小游戏。
如果一个用户玩过三次，当第四次启动时，提示：试玩三次结束，请续费！！
(提示：用户无论登录多少次，只要玩过三次，就不允许再玩了)
如果登录三次失败，程序不允许此用户继续登录了！
(说明：如果三次登录失败，即使重启程序，也不允许此用户登录了)
*/
2.代码实现如下：
import java.io.*;
import java.util.ArrayList;
import java.util.InputMismatchException;
import java.util.Random;
import java.util.Scanner;
public class Demo {
public static void main(String[] args) {
while (true) {
System.out.println("******欢迎来到猜数字系统******\r\n");
System.out.println("1.登录\t\t2.注册\t\t3.退出\r\n");
System.out.println("****************************");
System.out.println("请输入你要操作的序号：");
try {
int i = new Scanner(System.in).nextInt();
switch (i) {
case 1:
logon();
break;
case 2:
login();
break;
case 3:
System.exit(0);
default:
System.out.println("你输入的编号有误！");
}
} catch (InputMismatchException e) {
System.out.println("请输入序号！亲");
}
}
}
private static void logon() {
Scanner sc = new Scanner(System.in);
ArrayList list = readFile();
boolean b = list.isEmpty();
if (b){
System.out.println("当前系统没有用户！");
return;
}
while (!b){
System.out.println("请输入用户名：");
String name = sc.next();
String s1 = null;
for (String s : list) {
if (s.startsWith(name)){
s1 = s;
}
}
if (!list.contains(s1)){
System.out.print("用户名不存在，重新");
} else {
while (true) {
String[] split = s1.split(",");
if (Integer.parseInt(split[2])>0) {
System.out.println("请输入密码：");
String psw = sc.next();
if (psw.equals(split[1])) {
System.out.println("密码正确，登录成功！");
int i = guess(Integer.parseInt(split[3]));
list.remove(s1);
list.add(split[0]+","+split[1]+","+3+","+i);
writeFile(list);
return;
} else {
pswFalse(split[0]);
ArrayList list1 = readFile();
String s2 = null;
for (String s : list1) {
if (s.startsWith(name)) {
s2 = s;
}
}
String[] split1 = s2.split(",");
if (Integer.parseInt(split1[2]) > 0) {
System.out.print("密码错误，你还有" + split1[2] + "次机会，重新");
} else {
System.out.println("密码错误三次！已锁定，请联系管理员解锁。");
break;
}
}
}else {
System.out.println("您的帐号已锁定，请联系管理员解锁。");
return;
}
}
}
}
}
private static void login() {
ArrayList list = readFile();
Scanner sc = new Scanner(System.in);
while (true) {
System.out.println("请输入用户名：");
String name = sc.next();
String s1 = null;
for (String s : list) {
if (s.startsWith(name)){
s1 = s;
}
}
if (list.contains(s1)){
System.out.print("用户名已存在，重新");
}else {
System.out.println("请输入密码：");
String psw = sc.next();
list.add(name + "," + psw + ",3,3");
writeFile(list);
System.out.println("注册成功！");
break;
}
}
}
private static ArrayList readFile(){
ArrayList list = new ArrayList<>();
try (BufferedReader in = new BufferedReader(new FileReader("user_g.txt"))) {
String row = null;
while ((row = in.readLine()) != null){
list.add(row);
}
in.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return list;
}
private static void writeFile(ArrayList list){
try (BufferedWriter out = new BufferedWriter(new FileWriter("user_g.txt"))) {
for (String s : list) {
out.write(s);
out.newLine();
}
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
private static int guess(int index) {
System.out.println("欢迎来玩猜字小游戏");
if (index > 0) {
boolean b = true;
while (b) {
int number = new Random().nextInt(100) + 1;
System.out.println("请输入一个1到100之间的数字：");
index--;
while (true) {
int i = new Scanner(System.in).nextInt();
if (i == number) {
System.out.println("恭喜你猜对了！");
if (index >= 1) {
System.out.println("你还可以试玩" + index + "次。");
System.out.println("是否继续试玩？（是输入1，否输入0）");
int s = new Scanner(System.in).nextInt();
if (s == 0) {
b = false;
}
} else {
b = false;
System.out.println("试玩结束，请付费！");
}
break;
} else if (i > number) {
System.out.println("你猜大了，再猜！");
} else if (i < number) {
System.out.println("你猜小了，再猜！");
}
}
}
}else {
System.out.println("您的三次试玩已用完，请付费后再玩！");
}
return index;
}
private static void pswFalse(String n){
ArrayList list = readFile();
String s1 = null;
for (String s : list) {
if (s.startsWith(n)){
s1 = s;
}
}
String[] split = s1.split(",");
if (list.contains(s1)){
int i = Integer.parseInt(split[2]);
i = i-1;
list.remove(s1);
list.add(split[0]+","+split[1]+","+i+","+split[3]);
writeFile(list);
}
}
}