字符串至少包含一个数字

我试图查看字符串是否至少包含一个数字或小写或大写。

我写过这样的话：

int combinations = 0; string pass = "!!!AAabas1"; if (pass.matches("[0-9]")) { combinations = combinations + 10; } if (pass.matches("[az]")) { combinations =combinations + 26; } if (pass.matches("[AZ]")) { combinations =combinations + 26; } 

但是我不明白为什么我不能得到组合去36。他们只是保持在0.我做错了什么？

Answer 1

您可以使用Pattern，我认为“matches”方法查找整个字符串以匹配正则表达式。

尝试下一个代码：

  int combinations = 0; String pass = "!!AAabas1"; if (Pattern.compile("[0-9]").matcher(pass).find()) { combinations = combinations + 10; } if (Pattern.compile("[az]").matcher(pass).find()) { combinations = combinations + 26; } if (Pattern.compile("[AZ]").matcher(pass).find()) { combinations = combinations + 26; } 

Answer 2

这是我的尝试。 注意，这使用unicode类别进行validation，因此非拉丁语言友好。

 import java.util.regex.Pattern; public class PasswordValidator { public static void main(String[] args) { final PasswordValidator passwordValidator = new PasswordValidator(); for (String password : new String[] { "abc", "abc123", "ABC123", "abc123ABC", "!!!AAabas1", "гшщз", "гшщзЧСМИ22" }) { System.out.printf("Password '%s' is %s%n", password, passwordValidator.isValidPassword(password) ? "ok" : "INVALID"); } } private static final Pattern LOWER_CASE = Pattern.compile("\\p{Lu}"); private static final Pattern UPPER_CASE = Pattern.compile("\\p{Ll}"); private static final Pattern DECIMAL_DIGIT = Pattern.compile("\\p{Nd}"); /** * Determine if a password is valid. * * 
 * A password is considered valid if it contains: * 
 * 
At least one lower-case letter
 * 
At least one upper-case letter
 * 
At least one digit
 * 
 * * @param password * password to validate * @return True if the password is considered valid, otherwise false */ public boolean isValidPassword(final String password) { return containsDigit(password) && containsLowerCase(password) && containsUpperCase(password); } private boolean containsDigit(final String str) { return DECIMAL_DIGIT.matcher(str).find(); } private boolean containsUpperCase(final String str) { return UPPER_CASE.matcher(str).find(); } private boolean containsLowerCase(final String str) { return LOWER_CASE.matcher(str).find(); } } 

这是输出：

 Password 'abc' is INVALID Password 'abc123' is INVALID Password 'ABC123' is INVALID Password 'abc123ABC' is ok Password '!!!AAabas1' is ok Password 'гшщз' is INVALID Password 'гшщзЧСМИ22' is ok 

Answer 3

问题是matches尝试匹配整个输入字符串。

相反，尝试创建一个Pattern ，然后从那里创建一个Matcher ，然后使用find方法。

模式javadoc应该有很大帮助。

Answer 4

虽然使用正则表达式显然可以正常工作，但是Guava的CharMatcher类可能更适合您要做的事情：

 if (CharMatcher.inRange('0', '9').matchesAnyOf(pass)) combinations += 10; if (CharMatcher.inRange('a', 'z').matchesAnyOf(pass)) combinations += 26; if (CharMatcher.inRange('A', 'Z').matchesAnyOf(pass)) combinations += 26; 

Answer 5

 String str_rno = "CooL8"; boolean Flag = false; String[] parts = str_rno.split(""); for (int i = 0; i < str_rno.length(); i++) { String part1 = parts[i + 1]; if (Character.isDigit(str_rno.charAt(i))) { System.out.println(" " + i + " " + part1 + " digit"); Flag = true; } else { System.out.println(" " + i + " " + part1 + " char "); } } if(Flag==true){ Toast.makeText(getApplicationContext(),"String contain 1 digit",Toast.LENGTH_SHORT).show(); } if(Flag==flase){ Toast.makeText(getApplicationContext(),"String not contain 1 digit",Toast.LENGTH_SHORT).show(); }