(Class library use case analysis) Email verification

Enter an email address and use regular expressions to determine whether it is correct.

• Main method

 public static void main(String[] args) {
        String email = args[0];
        if(Validator.isEmail(email)){
            System.out.println("验证成功");
        }else{
            System.out.println("验证失败");
        }
    }

• Verification class

  class Validator{ //定义一个专门的验证程序类
      private Validator(){}
      public static boolean isEmail(String email){
          if(email == null || "".equals(email)){  //数据为空
              return false;
          }
          String regex = "\\w+@\\w+\\.\\w+";
          return email.matches(regex);
      }
  }