RTEditor/src/main/java/com/onegravity/rteditor/converter/tagsoup/ElementType.java
public static String normalize(String value) {
        if (value == null)
            return value;
        value = value.trim();
        if (value.indexOf("  ") == -1)
            return value;
        boolean space = false;
        int len = value.length();
        StringBuffer b = new StringBuffer(len);
        for (int i = 0; i < len; i++) {
            char v = value.charAt(i);
            if (v == ' ') {
                if (!space)
                    b.append(v);
                space = true;
            } else {
                b.append(v);
                space = false;
            }
        }
        return b.toString();
    }
public static String normalize(String value) {
        if (value == null)
            return value;
        value = value.trim();
        if (value.indexOf("  ") == -1)
            return value;
        boolean space = false;
        int len = value.length();
        StringBuffer b = new StringBuffer(len);
        for (int i = 0; i < len; i++) {
            char v = value.charAt(i);
            if (v == ' ') {
                if (!space)
                    b.append(v);
                space = true;
            } else {
                b.append(v);
                space = false;
            }
        }
        return b.toString();
    }
Normalize an attribute value (ID-style). CDATA-style attribute
normalization is already done.

@param value The value to normalize
@return The normalized value