Kotlin，无法匹配正则表达式 [英] Kotlin, cant match regex patters

问题描述

尝试了几个小时才能使这个简单的验证生效.看来我尝试检查的结果都不一致.

Been trying for hours to get this simple validation to work. It seems whatever i try to check, results are inconsistent..

    fun validatePassword(password: Password): Boolean {
    val noUpper = "(?=.*[A-Z])".toRegex()
    val noLower = "(?=.*[a-z])".toRegex()
    val noDigit = "(?=.*\\d)".toRegex()

    when {
        !password.newPassword.matches(noUpper) -> {
            throw WebApplicationException("Password missing uppercase letter")
        }
        !password.newPassword.matches(noLower) -> {
            throw WebApplicationException("Password missing digit")
        }
        !password.newPassword.matches(noDigit) -> {
            throw WebApplicationException("Password missing lowercase letter")
        }
        else -> return true
    }
}

我对正则表达式不太满意.我该如何正确检查这里显示的错误?

Im not too good with regex.. how do i get these to check properly agains the errors shown here?

谢谢

推荐答案

The matches() method requires a full string match, and your regexps only match an empty location followed with any 0+ chars other than line break chars followed with either an upper- or lowercase letters or a digit. You need to match and consume the whole string.

一种解决方法是仅修改正则表达式并按原样使用其余代码:

One fix is to modify just the regexps and use the rest of code as is:

val noUpper = "(?s)[^A-Z]*[A-Z].*".toRegex()
val noLower = "(?s)[^a-z]*[a-z].*".toRegex()
val noDigit = "(?s)\\D*\\d.*".toRegex()

或者，使用 find() (允许在更长的字符串内进行部分匹配)，并使用一些更简单的正则表达式:

Or, use find() (that allows partial matches inside longer strings) with a bit simpler regexes:

val noUpper = "[A-Z]".toRegex()
val noLower = "[a-z]".toRegex()
val noDigit = "\\d".toRegex()

然后

when {
    noUpper.find(password) == null -> {
        throw WebApplicationException("Password missing uppercase letter")
    }
    noLower.find(password) == null -> {
        throw WebApplicationException("Password missing digit")
    }
    noDigit.find(password) == null -> {
        throw WebApplicationException("Password missing lowercase letter")
    }
    else -> return true
}

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