Android中判斷字符是否爲中文、韓文、日文

時間 2019-12-07

原文原文鏈接

咱們常常須要在程序中判斷一個字符是否爲CJK（Chinese、Japanese、Korean）語言的字符。函數

例如，在Contacts裏面程序須要判斷聯繫人姓名的所屬語言。this

今天爲你們介紹一種NameSplitter中使用的判斷字符所屬語言的方法。spa

以判斷字符是否爲中文爲例。code

首先，經過guessFullNameStyle函數來判斷字符所屬語言(使用UnicodeBlock來判斷)；blog

    public static int guessFullNameStyle(String name) {
        if (name == null) {
            return FullNameStyle.UNDEFINED;
        }

        int nameStyle = FullNameStyle.UNDEFINED;
        int length = name.length();
        int offset = 0;
        while (offset < length) {
            int codePoint = Character.codePointAt(name, offset);
            if (Character.isLetter(codePoint)) {
                UnicodeBlock unicodeBlock = UnicodeBlock.of(codePoint);

                if (!isLatinUnicodeBlock(unicodeBlock)) {

                    if (isCJKUnicodeBlock(unicodeBlock)) {
                        // We don't know if this is Chinese, Japanese or Korean -
                        // trying to figure out by looking at other characters in the name
                        return guessCJKNameStyle(name, offset + Character.charCount(codePoint));
                    }

                    if (isJapanesePhoneticUnicodeBlock(unicodeBlock)) {
                        return FullNameStyle.JAPANESE;
                    }

                    if (isKoreanUnicodeBlock(unicodeBlock)) {
                        return FullNameStyle.KOREAN;
                    }
                }
                nameStyle = FullNameStyle.WESTERN;
            }
            offset += Character.charCount(codePoint);
        }
        return nameStyle;
    }

    private static int guessCJKNameStyle(String name, int offset) {
        int length = name.length();
        while (offset < length) {
            int codePoint = Character.codePointAt(name, offset);
            if (Character.isLetter(codePoint)) {
                UnicodeBlock unicodeBlock = UnicodeBlock.of(codePoint);
                if (isJapanesePhoneticUnicodeBlock(unicodeBlock)) {
                    return FullNameStyle.JAPANESE;
                }
                if (isKoreanUnicodeBlock(unicodeBlock)) {
                    return FullNameStyle.KOREAN;
                }
            }
            offset += Character.charCount(codePoint);
        }

        return FullNameStyle.CJK;
    }

其次，若是得到的結果是CJK，那麼咱們還要進一步判斷究竟是Chinese仍是Japanese仍是Koreanip

    /**
     * If the supplied name style is undefined, returns a default based on the
     * language, otherwise returns the supplied name style itself.
     * 
     * @param nameStyle See {@link FullNameStyle}.
     */
    public static int getAdjustedFullNameStyle(int nameStyle) {
        String mLanguage = Locale.getDefault().getLanguage().toLowerCase();
        if (nameStyle == FullNameStyle.UNDEFINED) {
            if (JAPANESE_LANGUAGE.equals(mLanguage)) {
                return FullNameStyle.JAPANESE;
            } else if (KOREAN_LANGUAGE.equals(mLanguage)) {
                return FullNameStyle.KOREAN;
            } else if (CHINESE_LANGUAGE.equals(mLanguage)) {
                return FullNameStyle.CHINESE;
            } else {
                return FullNameStyle.WESTERN;
            }
        } else if (nameStyle == FullNameStyle.CJK) {
            if (JAPANESE_LANGUAGE.equals(mLanguage)) {
                return FullNameStyle.JAPANESE;
            } else if (KOREAN_LANGUAGE.equals(mLanguage)) {
                return FullNameStyle.KOREAN;
            } else {
                return FullNameStyle.CHINESE;
            }
        }
        return nameStyle;
    }