1 String var = "userNameAndPassword";
2 Pattern humpPattern = Pattern.compile("[A-Z]");
3 Matcher matcher = humpPattern.matcher(var);
4 StringBuffer sb = new StringBuffer();
5 while (matcher.find()) {
6 matcher.appendReplacement(sb, "_" + matcher.group(0).toLowerCase());
7 }
8 matcher.appendTail(sb);
9 sb.toString()就是转换后小写的值
标签：下划线,驼峰,matcher,StringBuffer,小写,Pattern,sb From： https://www.cnblogs.com/wjz666/p/16712045.html