java - 为什么我可以使用 US Ascii Locale 来处理大写/小写的德语变音符号？

Question

建议如下代码:

package org.apache.creadur.rat2.core.ds;

import java.util.Locale;

public class TestUsAsciiLocale {
    public static void main(String[] pArgs) throws Exception {
        final String capitalLetterAe = "\u00c4";
        final String smallLetterAe = "\u00e4";
        if (capitalLetterAe.toLowerCase(Locale.GERMANY).equals(smallLetterAe)) {
            System.out.println("Capital Ae, and small ae are the same (case insensitive) in the german Locale.");
        }
        if (capitalLetterAe.toLowerCase(Locale.US).equals(smallLetterAe)) {
            System.out.println("Capital Ae, and small ae are the same (case insensitive) in the US Locale.");
        }
    }
}

输出如下:

Capital Ae, and small ae are the same (case insensitive) in the german Locale.
Capital Ae, and small ae are the same (case insensitive) in the US Locale.

我觉得这很奇怪。我希望美国 Ascii 语言环境能够准确对待 [a-zA-Z] 可大写/小写。

谢谢，

乔臣

Answer 1

您的代码中存在错误:

    if (capitalLetterAe.toLowerCase(Locale.GERMANY).equals(smallLetterAe)) {
        System.out.println("Capital Ae, and small ae are the " +
             "same (case insensitive) in the US Locale.");
    }

您正在使用 Locale.GERMANY，但消息显示“在美国区域设置”。