匹配花括号的Java regex -“无效转义序列”

I want to parse nested JSON strings by splitting them up recursively by { }. The regex I came up with is "{([^}]*.?)}", which I've tested appropriately grabs the string I want. However, when I try to include it in my Java I get the following error: "Invalid escape sequence (valid ones are \b \t \n \f \r \" \' \ )"

我想通过用{}递归地分割嵌套的JSON字符串来解析它们。我想出的正则表达式是“{([^ }]*。?)}”,我已经测试了适当地抓住我想要的字符串。然而，当我尝试在Java中包含它时，我得到了以下错误:“无效转义序列(有效的转义序列是\b \t \n \f \f \r \r \“\”\)”

This is my code, and where the error occurs:

这是我的代码，错误发生的地方:

String[] strArr = jsonText.split("\{([^}]*.?)\}");

What am I doing wrong?

我做错了什么?

5 个解决方案

#1

~~1. Curle braces have no special meaning here for regexp language, so they should not be escaped I think.~~

1。Curle花括号在这里对于regexp语言没有特殊的意义，所以我认为它们不应该被忽略。

If you want to escape them, you can. Backslash is an escape symbol for regexp, but it also should be escaped for Java itself with second backslash.

如果你想逃离他们，你可以。反斜杠是regexp的转义符号，但是对于Java本身，也应该用第二个反斜杠转义。
Why don't you escape curle brace inside grouping construct?

为什么你不能在分组结构中避免弯曲括号呢?
There are good JSON parsing libraries https://*.com/questions/338586/a-better-java-json-library

有很好的JSON解析库https://*.com/questions/338586/a-better-java-json-library
You are using reluctant quantifier, so it won't work with nested braces, for example for {"a", {"b", "c"}, "d"} it will match {"a", {"b", "c"}

您正在使用勉强量词，因此它不能使用嵌套的大括号，例如{a" a"， {"b"， "c"}， "d"}它将匹配{a"， "b"， "c"}

#2

The nasty thing about Java regexes is that java doesn't recognize a regex as a regex.
It accepts only \\, \', \" or \u[hexadecimal number] as valid escape sequences. You'll thus have to escape the backslashes because obviously \{ is an invalid escape sequence.
Corrected version:

Java regexes令人讨厌的地方是Java不承认regex是regex。它只接受\、\、\或\u[十六进制数字]作为有效的转义序列。因此，您必须转义反斜杠，因为显然\{是无效的转义序列。修正版:

String[] strArr = jsonText.split("\\{([^}]*.?)\\}");

#3

Double the backslashes:

双反斜杠:

String[] strArr = jsonText.split("\\{([^}]*.?)\\}");

#4

The regular expression should be

正则表达式应该是

"\\{([^}]*?)\\}"

. is not required!

。不需要!

#5

You need to escape your backslash with one more backslash. Since, \{ is not a valid escape sequence: -

你需要再用一个反斜杠来转义你的反斜杠。因为，\{不是一个有效的转义序列:-

String[] strArr = jsonText.split("\\{([^\\}]*.?)\\}");

You can refer to Pattern documentation for more information about escape sequences.

您可以参考模式文档了解更多关于转义序列的信息。

#1