布尔帮助：测试密码 JAVA 的参数 [重复]答案

【问题标题】：Boolean help: Testing the parameters for a password JAVA [duplicate]布尔帮助：测试密码 JAVA 的参数 [重复]
【发布时间】：2015-10-05 00:01:31
【问题描述】：

任务：

此程序应检查输入的密码是否至少包含 8 个字符、一个大小写字母、一个数字和一个特殊字符。

代码：

String password;
boolean hasLength;
boolean hasUppercase;
boolean hasLowercase;
boolean hasDigit;
boolean hasSpecial;

Scanner scan = new Scanner(System.in);
/******************************************************************************
*                             Inputs Section                                  *
******************************************************************************/
System.out.println("A password must be at least 8 character long");
System.out.println("And must contain:");
System.out.println("-At least 1 number");
System.out.println("-At least 1 uppercase letter");
System.out.println("-At least 1 special character (!@#$%^&*()_+)\n");
System.out.print("Please enter your new password: ");
password = scan.nextLine();

/******************************************************************************
*                           Processing Section                              *
******************************************************************************/
System.out.print("\n");
System.out.println("Entered Password:\t " + password);

hasLength = password.length() < 8; // parameters for length
// for lower and uppercase characters
hasUppercase = !password.equals(password.toUpperCase());
hasLowercase = !password.equals(password.toLowerCase());
hasDigit =  !password.matches("[0-9]");//checks for digits
hasSpecial = !password.matches("[A-Za-z]*"); //for anything not a letter in the ABC's


// the following checks if any of the instances are false, of so prints the statement
if(hasLength)
{
    System.out.println("Verdict: Invalid, Must have at least 8 characters");
}

if(!hasUppercase)
{
    System.out.println("Verdict: Invalid, Must have an uppercase Character");
}
if(!hasLowercase)
{
    System.out.println("Verdict: Invalid, Must have a lowercase Character");
}
if(!hasDigit)
{
    System.out.println("Verdict: Invalid, Must have a number");
}
if(!hasSpecial)
{
    System.out.println("Verdict: Invalid, Must have a special character");
}

如果我输入密码“水”，我得到：

Entered Password:    water
Verdict: Invalid, Must have at least 8 characters
Verdict: Invalid, Must have a lowercase Character
Verdict: Invalid, Must have a special character

【问题讨论】：

!password.equals(password.toLowerCase()); 不会测试“单个”小写字符，但如果整个密码都是小写，那么您的大写检查也是如此
我正要和我上面那个人说同样的话！
哇哦，呵呵。检查小写字符的好方法是什么。在 If 循环中检查每个字母是大写还是小写？
您可以改用hasUppercase = password.matches("(?s).*[A-Z]*"); 和hasLowercase = password.matches("(?s).*[a-z]*");
或import static org.apache.commons.lang3.StringUtils.*; /* ... */ boolean ok = !isAllUpperCase(password) && !isAllLowerCase(password);

标签： java boolean

【解决方案1】：

我认为大小写检查应该反之亦然：

hasUppercase = !password.equals(password.toLowerCase());
hasLowercase = !password.equals(password.toUpperCase());

因为密码的小写版本等于密码，只有不包含大写字母。

其他两个检查可以这样完成：

hasDigit = password.matches(".*[0-9].*");
hasSpecial = !password.matches("[A-Za-z0-9]*");

【讨论】：