为什么这个 Java 正则表达式会导致“非法转义字符”错误？
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原文地址: http://stackoverflow.com/questions/1379191/
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Why does this Java regex cause "illegal escape character" errors?
提问by Thomas Owens
I'm working on a solution to a previous question, as best as I can, using regular expressions. My pattern is
我正在使用正则表达式尽可能地解决上一个问题。我的模式是
"\d{4}\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}"
According to NetBeans, I have two illegal escape characters. I'm guessing it has to do with the \d and \w, but those are both valid in Java. Perhaps my syntax for a Java regular expression is off...
根据 NetBeans，我有两个非法转义字符。我猜它与\d 和\w 有关，但它们在Java 中都有效。也许我的 Java 正则表达式语法已关闭...
The entire line of code that is involved is:
涉及的整行代码是：
userTimestampField = new FormattedTextField(
new RegexFormatter(
"\d{4}\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}"
));
采纳答案by butterchicken
Assuming this regex is inside a Java Stringliteral, you need to escape the backslashes for your \dand \wtags:
假设这个正则表达式在 JavaString文字中，你需要为你的\d和\w标签转义反斜杠：
"\d{4}\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}"
This gets more, well, bonkersfrankly, when you want to match backslashes:
坦率地说，当您想要匹配反斜杠时，这会变得更加疯狂：
public static void main(String[] args) {
Pattern p = Pattern.compile("\\\\"); //ERM, YEP: 8 OF THEM
String s = "\\";
Matcher m = p.matcher(s);
System.out.println(s);
System.out.println(m.matches());
}
\ //JUST TO MATCH TWO SLASHES :(
true
回答by willcodejavaforfood
Did you try "\\d"and "\\w"?
你有没有尝试"\\d"和"\\w"？
-edit- Lol I posted the right answer and get down voted and then I notice that stackoverflow escapes backslashes so my answer appeared wrong :)
-edit-大声笑我发布了正确的答案并被否决了然后我注意到stackoverflow转义反斜杠所以我的答案似乎是错误的:)
回答by MystikSpiral
I think you need to add the two escaped shortcuts into character classes. Try this: "[\d]{4}[\w]{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}"
我认为您需要将两个转义快捷方式添加到字符类中。尝试这个： "[\d]{4}[\w]{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}"
--Good Luck.
- 祝你好运。
回答by asalamon74
What about the following: \\d{4}\\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}
以下情况如何： \\d{4}\\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}
回答by Christopher Klewes
Have you tried this?
你试过这个吗？
\d{4}\w{3}(0[1-9]|[12][0-9]|3[01])([01][0-9]|2[0-3])([0-5][0-9]){2}
回答by Daniel
all you need to do is to put
你需要做的就是把
*\
ex: string ex = 'this is the character: *\s';
before your invalid character and not 8 \ !!!!!
在您的无效字符之前而不是 8 \ !!!!!!
