在Java正则表达式中向字符类添加方括号 [英] Adding square brackets to character class in Java regex

问题描述

我想逐行从文件lne读取内容String，并在每一行中删除不是以下[ { } ]之一的所有caharcters 我想使用一种方法:

I would like to read a content String from file lne by line, and in each line remove all caharcters that are not one of the following [ { } ] I wanted to used a method:

line = line.replaceAll("[^[({})]]","");

，但问题是char [和]在正则表达式语法中意味着其他含义. 如何处理?

but the problem is that char [ and ] means in regex syntax something else. How to deal with it?

最诚挚的问候

推荐答案

在Java中，正则表达式字符类可以具有并集和交集，因此，如果要对[和]进行转义，则必须在它们内部进行转义.作为文字符号.并且由于\可用于定义转义序列，因此应将其加倍以表示文字正则表达式转义的\.

In Java, the regex character classes can have unions and intersections, thus, [ and ] must be escaped inside if you want them to be treated as literal symbols. And since \ can be used to define escape sequences, it should be doubled to denote a literal regex-escaping \.

使用

line = line.replaceAll("[^\\[({})\\]]","");
                          ^^     ^^

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