缓冲输入输出流实现用户登录注册

package cn.itcast.buffered;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.util.Scanner;/*练习： 缓冲输入输出字符流用户登陆注册...*/public class Login {static Scanner scanner = new Scanner(System.in);public static void main(String[] args) throws IOException {while(true){System.out.println("请选择功能： A(注册)   B(登陆)");String option =  scanner.next();if("a".equalsIgnoreCase(option)){//注册reg();}else if("b".equalsIgnoreCase(option)){//登陆login();}else{System.out.println("你的输入有误,请重新输入...");}}}//登陆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;//读取文件的信息，查看是否有该用户的信息存在，如果存在则登陆成功。//建立数据的输入通道//建立缓冲输入字符流BufferedReader bufferedReader = new BufferedReader(new FileReader("F:\\users.txt"));String line = null;boolean isLogin = false; // 用于记录是否登陆成功的标识， 默认是登陆失败的。//不断的读取文件的内容while((line = bufferedReader.readLine())!=null){if(info.equals(line)){isLogin = true;break;}}if(isLogin){System.out.println("欢迎"+userName+"登陆成功...");}else{System.out.println("不存在该用户信息，请注册!!");}}//注册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;//把用户的注册的信息写到文件上File file = new File("F:\\users.txt");FileWriter fileWriter = new FileWriter(file,true);//建立缓冲输出字符流BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);//把用户信息写出bufferedWriter.write(info);bufferedWriter.newLine();//关闭资源bufferedWriter.close();}}