用于除去模式以外的所有字符的Java正则表达式

Question

我有一个字符串包括电子邮件。在它之前和/或之后可能有额外的字符。输入示例：

[e-mail]
[e-mail] abcd efg
x y z [e-mail]
p q [e-mail] x z
asd[[e-mail]]gh

[e-mail]
[e-mail]
[e-mail]
[e-mail]
[e-mail]

if (s.matches("(?i).*\\s[a-zA-Z_\\.]+@[a-zA-Z_\\.]+\\.[a-zA-Z_\\.]+.*") ||
    fields[2].matches("(?i).*[a-zA-Z_\\.]+@[a-zA-Z_\\.]+\\.[a-zA-Z_\\.]+\\s.*"))

Answer 1

您可以使用java.util.regex.pattern和java.util.regex.matcher

此代码将执行您所要求的操作：

public static void main(String[] args) {
    String[] testList = {"[e-mail]", 
            "[e-mail] abcd efg", 
            "x y z [e-mail]", 
            "p q [e-mail] x z", 
            "asd[[e-mail]]gh"};

    Pattern EMAIL_PATTERN = Pattern.compile("[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9-]+(\\.[A-Za-z0-9-]+)*(\\.[A-Za-z]{2,})");


    for(String test : testList){
        Matcher m = EMAIL_PATTERN.matcher(test);
        while (m.find()) {
             System.out.println(m.group(0));
        }
    }
}