java实现驼峰和下划线相互转换

记录一波，工作使用到直接copy。

   
    public static String humpToUnderline(String str) {
        Pattern compile = Pattern.compile("[A-Z]");
        Matcher matcher = compile.matcher(str);
        StringBuffer sb = new StringBuffer();
        while(matcher.find()) {
            matcher.appendReplacement(sb,  "_" + matcher.group(0).toLowerCase());
        }
        matcher.appendTail(sb);
        return sb.toString();
    }

 
    public static String underlineToHump(String str) {
        str = str.toLowerCase();
        Pattern compile = Pattern.compile("_[a-z]");
        Matcher matcher = compile.matcher(str);
        StringBuffer sb = new StringBuffer();
        while(matcher.find()) {
            matcher.appendReplacement(sb,  matcher.group(0).toUpperCase().replace("_",""));
        }
        matcher.appendTail(sb);
        return sb.toString();
    }