Question

我正在尝试将http://cpansearch.perl.org/src/DSTAAL/Mail-Log-Parse-1.0400/lib/Mail/Log/Parse/Postfix.pm转换为Java。

给出perl代码片段

@{$line_info{to}} = $line_info{text} =~ m/\bto=([^,]+),/g;

等同于java伪代码

if (lineInfo.getText().contains("<beginning of word or sentence>to=")) {
    lineInfo.setTo(lineInfo.getText().<get text between 'to=' and comma?>);
}

有人能给我一个有用的Java示例吗？

示例输入行可能是

Apr 22 07:08:33 server postfix/smtpd[19793]: NOQUEUE: filter: RCPT from mail-eopbgr50060.outbound.protection.outlook.com[40.107.5.60]: <someone@something.co.uk>: Sender address triggers FILTER smtp-amavis:[127.0.0.1]:10024; from=<someone@something.co.uk> to=<someone2@something2.co.uk> proto=ESMTP helo=<EUR03-VE1-obe.outbound.protection.outlook.com>

我希望lineInfo.setTo()设置为someone2@something2.co.uk

Answer 1

要获取捕获组的文本，您需要使用Pattern和Matcher类。

Pattern p = Pattern.compile("\\bto=([^,]+),"); // remember to double the \ escape
Matcher m = p.matcher(lineInfo.getText());
List<String> list = new ArrayList<>();
while (m.find()) {
    list.add(m.group(1)); // add text in capture group 1 to the list
}
lineInfo.setTo(list);

作为单一陈述，在Java 9+中，您可以使用流：

lineInfo.setTo(Pattern.compile("\\bto=([^,]+),")
                      .matcher(lineInfo.getText())
                      .results()
                      .map(r -> r.group(1))
                      .collect(Collectors.toList()));

将Perl正则表达式转换为Java

1 个答案: