我试图编写一个扰流器识别系统,以便将字符串中的任何扰流器替换为指定的扰流器字符。
我想匹配一个用方括号括起来的字符串,这样方括号内的内容就是捕获组1,包括周围括号在内的整个字符串就是匹配项。
我当前正在使用\[(.*?]*)\]
,对此答案here中的表达式进行了少许修改,因为我还希望嵌套方括号成为捕获组1的一部分。
该表达式的问题在于,尽管它可以工作并匹配以下内容:Jim ate a [sandwich]
将[sandwich]
与sandwich
作为组1进行匹配Jim ate a [sandwich with [pickles and onions]]
将[sandwich with [pickles and onions]]
与sandwich with [pickles and onions]
作为组1进行匹配[[[[]
将[[[[]
与[[[
作为组1进行匹配[]]]]
将[]]]]
与]]]
作为组1进行匹配
但是,如果我要匹配以下内容,它将无法正常工作:Jim ate a [sandwich with [pickles] and [onions]]
匹配两个:[sandwich with [pickles]
,其中sandwich with [pickles
作为组1[onions]]
,其中onions]
作为组1
我应该使用哪种表达式来匹配[sandwich with [pickles] and [onions]]
和sandwich with [pickles] and [onions]
作为组1?
编辑:
由于似乎无法使用正则表达式在Java中实现此功能,是否有替代解决方案?
编辑2:
我还希望能够通过找到的每个匹配项来拆分字符串,因此由于String.split(regex)
方便,因此正则表达式的替代方案将难以实现。这是一个例子:Jim ate a [sandwich] with [pickles] and [dried [onions]]
匹配所有:[sandwich]
,其中sandwich
作为组1[pickles]
,其中pickles
作为组1[dried [onions]]
,其中dried [onions]
作为组1
拆分句子应如下所示:
Jim ate a
with
and
最佳答案
更直接的解决方案
This solution将省略空白或仅空白子字符串
public static List<String> getStrsBetweenBalancedSubstrings(String s, Character markStart, Character markEnd) {
List<String> subTreeList = new ArrayList<String>();
int level = 0;
int lastCloseBracket= 0;
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == markStart) {
level++;
if (level == 1 && i != 0 && i!=lastCloseBracket &&
!s.substring(lastCloseBracket, i).trim().isEmpty()) {
subTreeList.add(s.substring(lastCloseBracket, i).trim());
}
}
} else if (c == markEnd) {
if (level > 0) {
level--;
lastCloseBracket = i+1;
}
}
}
if (lastCloseBracket != s.length() && !s.substring(lastCloseBracket).trim().isEmpty()) {
subTreeList.add(s.substring(lastCloseBracket).trim());
}
return subTreeList;
}
然后,将其用作
String input = "Jim ate a [sandwich][ooh] with [pickles] and [dried [onions]] and ] [an[other] match] and more here";
List<String> between_balanced = getStrsBetweenBalancedSubstrings(input, '[', ']');
System.out.println("Result: " + between_balanced);
// => Result: [Jim ate a, with, and, and ], and more here]
原始答案(更复杂,显示了提取嵌套括号的方法)
您还可以提取平衡括号内的所有子字符串,然后将其拆分:
String input = "Jim ate a [sandwich] with [pickles] and [dried [onions]] and ] [an[other] match]";
List<String> balanced = getBalancedSubstrings(input, '[', ']', true);
System.out.println("Balanced ones: " + balanced);
List<String> rx_split = new ArrayList<String>();
for (String item : balanced) {
rx_split.add("\\s*" + Pattern.quote(item) + "\\s*");
}
String rx = String.join("|", rx_split);
System.out.println("In-betweens: " + Arrays.toString(input.split(rx)));
此函数将找到所有
[]
平衡的子字符串:public static List<String> getBalancedSubstrings(String s, Character markStart,
Character markEnd, Boolean includeMarkers) {
List<String> subTreeList = new ArrayList<String>();
int level = 0;
int lastOpenBracket = -1;
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (c == markStart) {
level++;
if (level == 1) {
lastOpenBracket = (includeMarkers ? i : i + 1);
}
}
else if (c == markEnd) {
if (level == 1) {
subTreeList.add(s.substring(lastOpenBracket, (includeMarkers ? i + 1 : i)));
}
if (level > 0) level--;
}
}
return subTreeList;
}
见IDEONE demo
代码执行的结果:
Balanced ones: ['[sandwich], [pickles], [dried [onions]]', '[an[other] match]']
In-betweens: ['Jim ate a', 'with', 'and', 'and ]']
积分:
getBalancedSubstrings
基于peter.murray.rust对How to split this “Tree-like” string in Java regex? post的回答。