如何拆分逗号分隔的字符串，而忽略转义的逗号？ [英] How to split a comma separated String while ignoring escaped commas?

问题描述

我需要编写一个扩展版本的StringUtils.commaDelimitedListToStringArray函数，它获得一个额外的参数：转义字符

所以调用我的：

  commaDelimitedListToStringArray（test，test\\\，test\\，test，test，\\）
  

应返回：

  [test，test，test，test，test] 
  

我目前尝试使用String.split（）使用正则表达式拆分String：

  String [] array = str.split（[^ \\\\]，）; 
  

但返回的数组是：

  [tes，test\，test\，tes，test] 
  

任何想法？

解决方案

正则表达式

  [^ \\]，
  

表示匹配不是反斜杠后跟逗号的字符 - 这就是为什么 t，等模式匹配的原因，因为 t 是不是反斜杠的字符。

我认为您需要使用某种 negative lookbehind ，捕获未包含 \ 的，字符，例如

 （？<！\\），
  
 
 
 
（注意，我有意没有双重转义反斜杠，使其更易读）
 
I need to write a extended version of the StringUtils.commaDelimitedListToStringArray function which gets an additional parameter: the escape char.

so calling my:
commaDelimitedListToStringArray("test,test\\,test\\,test,test", "\\")
should return:
["test", "test,test,test", "test"]



My current attempt is to use String.split() to split the String using regular expressions:
String[] array = str.split("[^\\\\],");
But the returned array is:
["tes", "test\,test\,tes", "test"]
Any ideas?
解决方案
The regular expression
[^\\],
means "match a character which is not a backslash followed by a comma" - this is why patterns such as t, are matching, because t is a character which is not a backslash. 

I think you need to use some sort of negative lookbehind, to capture a , which is not preceded by a \ without capturing the preceding character, something like
(?<!\\),
(BTW, note that I have purposefully not doubly-escaped the backslashes to make this more readable)

                        
这篇关于如何拆分逗号分隔的字符串，而忽略转义的逗号？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！