我无法转换为资本的第一个字母的字符串：

I'm having trouble converting the first letter to Capital in a String:

rackingSystem.toLowerCase(); // has capitals in every word, so first convert all to lower case
StringBuilder rackingSystemSb = new StringBuilder();
rackingSystemSb.append(rackingSystem);
rackingSystemSb.setCharAt(0, Character.toUpperCase(rackingSystemSb.charAt(0))); 
rackingSystem = rackingSystemSb.toString();

似乎这不是工作..

This doesn't seem to work..

有什么建议？

推荐答案

试着做：

rackingSystem = rackingSystem.toLowerCase();

相反的：

rackingSystem.toLowerCase(); 

字符串是不可变的，你必须重新分配与toLowerCase的结果（）。

不过更简单，（只要你的字符串大于长度2大）：

Easier though, (as long as your String is larger than length 2):

rackingSystem = rackingSystem.substring(0,1).toUpperCase() + rackingSystem.substring(1).toLowerCase();