Java Regex模式匹配在任何字符序列之后首次出现“边界” [英] Java Regex pattern matching first occurrence of “boundary” after any character sequence

问题描述

我想设置一个模式，它会找到第一次出现的边界限制的捕获组。但现在使用了最后一个边界。

I want to set a pattern which will find a capture group limited by the first occurrence of the "boundary". But now the last boundary is used.

例如：

String text = "this should match from A to the first B and not 2nd B, got that?";
Pattern ptrn = Pattern.compile("\\b(A.*B)\\b");
Matcher mtchr = ptrn.matcher(text);
while(mtchr.find()) {
    String match = mtchr.group();
    System.out.println("Match = <" + match + ">");
}

打印：

"Match = <A to the first B and not 2nd B>"

我希望它打印出来：

"Match = <A to the first B>"

我需要在模式中更改什么？

What do I need to change within the pattern?

推荐答案

使用 * 非贪婪 / 不情愿使用 *？：

Pattern ptrn = Pattern.compile("\\b(A.*?B)\\b");

默认情况下，模式会表现得很贪婪，并且匹配尽可能多的字符以满足模式，也就是说，直到最后 B 。

By default, the pattern will behave greedily, and match as many characters as possible to satisfy the pattern, that is, up until the last B.

从不情愿的量词 /docs.oracle.com/javase/6/docs/api/java/util/regex/Pattern.html\"rel =noreferrer>文档，以及本教程。

See Reluctant Quantifiers from the docs, and this tutorial.

这篇关于Java Regex模式匹配在任何字符序列之后首次出现“边界”的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！