从字符串构建char [英] Build char from string

问题描述

我想允许用户通过XML配置文件指定Unicode范围。例如。他们可以指定0100..017F作为范围。对于我的（Java）应用程序使用这个字符范围，我需要将XML输入（String）转换为类型char。任何想法？＃

I want to allow a user specify a Unicode range via an XML config file. E.g. they could state 0100..017F as the range. For my (Java) app to consume this char range, I need to convert the XML input (String) to type char. Any ideas?#

Eg

String input = "0100..017F"; // I can change format of input, if enables a solution
char from = '\u0100';
char to = '\u017f';

谢谢。

推荐答案

如果它始终与该格式完全匹配，则这将足够：

If it always matches exactly that format, then this will suffice:

char from = (char)Integer.parseInt(input.substring(0, 4), 16);
char to = (char)Integer.parseInt(input.substring(6), 16);

更灵活的功能：

char from;
char to;
java.util.regex.Matcher m = java.util.regex.Pattern.compile(
    "^([\\da-fA-F]{1,4})(?:\\s*\\.\\.\\s*([\\da-fA-F]{1,4}))?$").matcher(input);
if (!m.find()) throw new IllegalArgumentException();
from = (char)Integer.parseInt(m.group(1), 16);
if (m.group(2) != null) {
    to = (char)Integer.parseInt(m.group(2), 16);
} else {
    to = from;
}

这允许每个字符使用1到4个十六进制数字， .. 可能在其周围有空格，并且范围的到部分可以省略，并假设等于来自。

That allows for 1 to 4 hex digits for each character, the .. may have space around it, and the to part of the range may be omitted and assumed to be equal to from.

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