package cn.lyjs.buffered; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.util.Scanner; public class Login { static Scanner scanner=new Scanner(System.in); public static void main(String[] args) throws IOException { while(true){ System.out.println("注册请输入:A 登录请输入 :B"); String ch=scanner.next(); if(ch.equalsIgnoreCase("A")){ Reg(); }else if(ch.equalsIgnoreCase("B")){ Login(); }else{ System.out.println("你输入有误,请重新输入:"); } } } public static void Login() throws IOException{ System.out.println("请输入用户名:"); String username=scanner.next(); System.out.println("请输入密码:"); String password=scanner.next(); String info=username+" "+password; File file=new File("E:\user.txt"); FileReader fileReader=new FileReader(file); BufferedReader bufferedReader=new BufferedReader(fileReader); boolean isTrue=false; String line=null; while((line=bufferedReader.readLine())!=null){ if(line.equals(info)){ isTrue=true; } } if(isTrue){ System.out.println("欢迎你成功登录"); }else{ System.out.println("用户名或密码错误,请重新登录"); } } public static void Reg() throws IOException{ System.out.println("请输入用户名:"); String username=scanner.next(); System.out.println("请输入密码:"); String password=scanner.next(); String info=username+" "+password; File file=new File("E:\user.txt"); FileWriter fileWriter=new FileWriter(file,true); BufferedWriter bufferedWriter=new BufferedWriter(fileWriter); bufferedWriter.append(info); bufferedWriter.newLine(); bufferedWriter.close(); System.out.println("你已经注册成功"); } }