package case_package1; import java.io.*; import java.util.Scanner; public class Login { public static void main(String[] args) throws IOException { /* 需求:写一个登录小案例 步骤: 将正确的用户名和密码手动保存在本地的userinfo.txt文件中 保存格式为:username=zhangsan&password=123&count=0 让用户键盘录入用户名和密码 比较用户录入的和正确的用户名密码是否一致 如果一致则打印登录成功 如果不一致则打印登录失败 */ //1、读取正确的用户名和密码 BufferedReader br = new BufferedReader(new FileReader("/Users/zhaoxiaoyong/Documents" + "/Java/IO_stream_project/Case_module/src/userinfo.txt")); String line = br.readLine(); br.close(); // username=zhangsan&password=123&count=0 String[] userinfo = line.split("&"); String[] arr1 = userinfo[0].split("="); String[] arr2 = userinfo[1].split("="); String[] arr3 = userinfo[2].split("="); String rightUsername = arr1[1]; String rightPassword = arr2[1]; int count = Integer.parseInt(arr3[1]); //2、用户键盘录入用户名和密码 Scanner sc = new Scanner(System.in); System.out.println("请输入用户名:"); String username = sc.nextLine(); System.out.println("请输入密码:"); String password = sc.nextLine(); //3、比较 if (rightUsername.equals(username) && rightPassword.equals(password) && count < 3) { System.out.println("登录成功"); } else { count++; if (count < 3) { System.out.println("登录失败,还剩下" + (3 - count) + "次机会"); } else { System.out.println("用户账户被锁定"); } writeInfo("username=" + rightUsername + "&password=" + rightPassword + "&count=" + count); } } /* * 作用: * 写出一个字符串到本地文件中 * 参数: * 要写的字符串 * */ private static void writeInfo(String content) throws IOException { BufferedWriter bw = new BufferedWriter(new FileWriter("/Users/zhaoxiaoyong/Documents/Java" + "/IO_stream_project/Case_module/src/userinfo.txt")); bw.write(content); bw.close(); } }