Question

我希望匹配以下内容：零长度行，匹配在非零长度的行中继续，直到特定字符串在一行中匹配。例如：匹配从零长度线开始，一直持续到达到STOP：

Some random text I don't care about

The match starts at the beginning of this line
The match continues across this line
The match stops here STOP more
text I don't care about

有什么建议吗？

由于

Answer 1

这应该这样做：

(?ms)^[ \t]*+$\s*+((?:(?!STOP).)*+)

一个小小的演示：

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main { 
    public static void main(String[] args) {
        String text = "Some random text I don't care about"      + "\n" +
                ""                                               + "\n" +
                "The match starts at the beginning of this line" + "\n" +
                "The match continues across this line"           + "\n" +
                "The match stops here STOP more"                 + "\n" +
                "don't care about"                               + "\n" +
                ""                                               + "\n" +
                ""                                               + "\n" +
                ""                                               + "\n" +
                "foo"                                            + "\n" +
                "barSTOP"                                        + "\n" +
                "text I don't care about";
        Matcher m = Pattern.compile("(?ms)^[ \t]*+$\\s*+(?:(?!STOP).)*+").matcher(text);
        while(m.find()) {
            System.out.println("match ->"+m.group()+"<-");
        }
    }
}

将输出：

match ->
The match starts at the beginning of this line
The match continues across this line
The match stops here <-
match ->


foo
bar<-

一个小小的解释：

(?ms)               # enable mutli-line and dot-all
^[ \t]*+$           # match and empty line
\s*+                # match the line break
(                   # start group 1
  (?:(?!STOP).)     #   if the string 'STOP' cannot be seen, match any character
  *+                #   match the previous zero or more times (possessively)
)                   # stop group 1

Answer 2

确保设置“匹配多行”标志，表达式为"\\n(\\n.*STOP)"。第一个（也是唯一一个）匹配组产生结果。在DOS和Windows系统上，使用"\\r\\n"代替"\\n"。

Answer 3

(?ms)^$(.+)STOP

正则表达式从零长度行开始并在Java中继续跨行

3 个答案: