将字符串转换为大驼峰，大写前面补空格，最后去掉左侧空格，如“test

public static String toUpperCaseAndSplitWithSpace(String str) {
    String result = "";
    String to = CaseFormat.UPPER_UNDERSCORE.to(CaseFormat.UPPER_CAMEL, str);
    char[] chars = to.toCharArray();
    for (int i = 0; i < chars.length; i++) {
        if (chars[i] >= 65 && chars[i] <= 91) {
            if (i != 1) {
                result += " ";
            }
        }
        result += chars[i];
    }
    if (!StringUtils.isEmpty(str)) {
        result = result.replaceAll("^[ ]+", "");
    }
    return result;
}