alpha 和空格的 java 正则表达式包括 [] \
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java regex for alpha and spaces is including [ ] \
提问by KisnardOnline
This is my regex for my JTextField to not be longer than x characters and to not include anything other than letters or spaces. For some reason it is allowing [ ] and \ characters.This is driving me crazy. Is my regex wrong??
这是我的 JTextField 的正则表达式，不超过 x 个字符，并且不包含字母或空格以外的任何内容。 出于某种原因，它允许 [ ] 和 \ 字符。这真让我抓狂。我的正则表达式错了吗？？
package com.jayavon.game.helper;
import java.awt.Toolkit;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;
public class CharacterNameCreationDocument extends PlainDocument {
private static final long serialVersionUID = 1L;
private int limit;
public CharacterNameCreationDocument(int limit) {
super();
this.limit = limit;
}
public void insertString(int offset, String str, AttributeSet attr) throws BadLocationException {
if (str == null || (getLength() + str.length()) > limit || !str.matches("[a-zA-z\s]*")){
Toolkit.getDefaultToolkit().beep();
return;
} else {
super.insertString(offset, str, attr);
}
}
}
回答by Alan Moore
You have a typo in your regex:
您的正则表达式中有一个错字：
"[a-zA-z\s]*"
[A-z]matches all the uppercase and lowercase letters plus[, ], ^, _, backslash and backtick, whose code points happen to lie between Zand a.
[A-z]匹配所有大写和小写字母加[、]、^、_、反斜杠和反引号，其代码点恰好位于Z和之间a。
Also, I agree with @?mega that you probably should be using an actual space character instead of \s:
另外，我同意 @?mega 您可能应该使用实际的空格字符而不是\s：
"[a-zA-Z ]*"
The anchors (^and $) aren't necessary since you're using the matches()method, which automatically anchors the match at both ends. They don't hurt anything though, and they do help communicate your intent.
锚点 (^和$) 不是必需的，因为您使用的是该matches()方法，该方法会自动在两端锚定匹配项。不过，它们不会伤害任何东西，它们确实有助于传达您的意图。
回答by ?mega
You should use regex pattern
您应该使用正则表达式模式
^[a-zA-Z\s]*$
where ^is start of string and $represents end of string.
其中^是字符串的开头，$代表字符串的结尾。
You can also extend such regex to check the string size. Let's say if you want allow minimum 5characters and maximum 20characters
您还可以扩展此类正则表达式以检查字符串大小。假设您想允许最少5字符数和最多20字符数
^[a-zA-Z\s]{5,20}$
However, because whitespace \\scan be not just space-bar character, but also other charactes, such as new-line, tab, etc., you may want to limit this just to real space-bar characters using
但是，因为空白不仅\\s可以是空格字符，还可以是其他字符，例如换行符、制表符等，您可能希望将其限制为真正的空格字符，使用
^[a-zA-Z ]{5,20}$
Additionaly, you might want to limit multiple space characters to be used in sequence. If so, use
此外，您可能希望限制按顺序使用多个空格字符。如果是这样，请使用
^(?!.* {2,})[a-zA-Z ]{5,20}$`
You might want string always to start and end with non-space characters. To add such feature go with
您可能希望字符串始终以非空格字符开头和结尾。要添加这样的功能去
^(?=.{5,20}$)(?!.* {2,})[a-zA-Z][a-zA-Z ]*[a-zA-Z]$
回答by John Woo
reformat your regex into this:
将您的正则表达式重新格式化为：
^[A-Za-z\s]{0,3}$
just change 3 to your desired length.
只需将 3 更改为您想要的长度。
