java 正则表达式 实例说明
如下是摘录的正则表达式的规则说明：
| Metacharacter | Function | Example | What It Matches |
|---|---|---|---|
| ^ | Beginning-of-line anchor | /^love/ | Matches all lines beginning with love. |
| $ | End-of-line anchor | /love$/ | Matches all lines ending with love. |
| . | Matches one character | /l..e/ | Matches lines containing an l, followed by two characters, followed by an e. |
| * | Matches zero or more of the preceding characters | / *love/ | Match lines with zero or more spaces, followed by the patternlove. |
| [ ] | Matches one in the set | /[Ll]ove/ | Matches lines containing love or Love. |
| [x–y] | Matches one character within a range in the set | /[A–Z]ove/ | Matches letters from A through Z followed by ove. |
| [^ ] | Matches one character not in the set | /[^A–Z]/ | Matches any character not in the range betweenA andZ. |
| \ | Used to escape a metacharacter | /love\./ | Matches lines containing love, followed by a literal period. Normally the period matches one of any character. |
| Additional metacharacters are supported by many UNIX programs that use RE metacharacters: | |||
| \< | Beginning-of-word anchor | /\ |
Matches lines containing a word that begins withlove (supported byvi andgrep). |
| \> | End-of-word anchor | /love\>/ | Matches lines containing a word that ends withlove (supported byvi andgrep). |
| \(..\) | Tags match characters to be used later | /\(love\)able \1er/ | May use up to nine tags, starting with the first tag at the left-most part of the pattern. For example, the patternlove is saved as tag 1, to be referenced later as\1; in this example, the search pattern consists oflovable followed bylover (supported bysed, vi, andgrep). |
| x{m\}or x{m,\}or x{m,n\} | Repetition of character x, m times, at least m times, at least m and not more than n times[a] | o{5,10\} | Matches if line contains between 5 and 10 consecutive occurrences of the letter o (supported byvi andgrep). |
实例说明:
预定义字符类 . 任何字符（与行结束符可能匹配也可能不匹配） \d 数字：[0-9] \D 非数字： [^0-9] \s 空白字符：[ \t\n\x0B\f\r] \S 非空白字符：[^\s] \w 单词字符：[a-zA-Z_0-9] \W 非单词字符：[^\w]^为限制开头
^java条件限制为以Java为开头字符
$为限制结尾
java$条件限制为以java为结尾字符
.条件限制除\n以外任意一个单独字符
java..条件限制为java后除换行外任意两个字符
加入特定限制条件[]
[a-z]条件限制在小写atoz范围中一个字符
[A-Z]条件限制在大写AtoZ范围中一个字符
[a-zA-Z]条件限制在小写atoz或大写AtoZ范围中一个字符
[0-9]条件限制在小写0to9范围中一个字符
[0-9a-z]条件限制在小写0to9或atoz范围中一个字符
[0-9[a-z]]条件限制在小写0to9或atoz范围中一个字符(并集)
[a-z&&[aeiou]]条件限制在atoz范围与aeiou字符的（交集）
[]中加入^后加再次限制条件[^]
[^a-z]条件限制在非小写atoz范围中一个字符
[^A-Z]条件限制在非大写AtoZ范围中一个字符
[^a-zA-Z]条件限制在非小写atoz或大写AtoZ范围中一个字符
[^0-9]条件限制在非小写0to9范围中一个字符
[^0-9a-z]条件限制在非小写0to9或atoz范围中一个字符
[^0-9[a-z]]条件限制在非小写0to9或atoz范围中一个字符
集锦复习:
[abc] a、b 或 c（简单类）
[^abc] 任何字符，除了 a、b 或 c（否定）
[a-zA-Z] a 到 z 或 A 到 Z，两头的字母包括在内（范围）
[a-d[m-p]] a 到 d 或 m 到 p：[a-dm-p]（并集）
[a-z&&[def]] d、e 或 f（交集）
[a-z&&[^bc]] a 到 z，除了 b 和 c：[ad-z]（减去）
[a-z&&[^m-p]] a 到 z，而非 m 到 p：[a-lq-z]（减去）
在限制条件为特定字符出现0次以上时，可以使用「*」J*0个以上J
.* 0个以上任意字符
J.*D J与D之间0个以上任意字符
在限制条件为特定字符出现1次以上时，可以使用「+」J+1个以上J
.+ 1个以上任意字符
J.+D J与D之间1个以上任意字符
实例场景 电话号码有效性检测正则使用：
public static boolean phoneFormat(String phone){
final String pattern1 = ("^((13[0-9])|(15[^4,\\D])|(18[0,5-9]))\\d{8}$");
//等同于 "^((13[0-9])|(15[\\d&&[^4]])|(18[0,5-9]))\\d{8}$" 其中[\\d&&[^4]]表示交集 0-9同时非4 交集就是【0-35-9】
//正则检测合法的手机号码
//130 131 132 133 134 135 136 137 138 139
//150 151 152 153 155 156 157 158 159
//180 185 186 187 188 189
final Pattern pattern = Pattern.compile(pattern1);
final Matcher mat = pattern.matcher(phone);
if (!mat.matches()) {
return false;
}
return true;
}
实例场景 邮箱号码有效性检测正则使用：
final String pattern2 = "^\\w+([-+.]\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*$";
//([-+.]\\w+)* （）内表示 ：-+.以及a-zA-Z_0-9 至少一个 ，（）*表示：0-任意个（）中内容
final Pattern pattern = Pattern.compile(pattern2);
final Matcher mat = pattern.matcher(email);
System.out.println(mat.matches());
附件: