//Created By ybb
Scanner scanner = new Scanner(System.in);
        int chance = 3;
        for (int i = 1; i <=chance; i++) {
            System.out.println("请输入用户名");
            String name = scanner.next();
            System.out.println("请输入密码");
            int password = scanner.nextInt();
            if ( name.equals("张三")&& password==666){
                System.out.println("登录成功");
                break;
            }else{
                System.out.println("你还有"+(chance-i)+"次机会");
            }
        }

注意点：
1，字符串对比要用equals
2，判断值相等要用==