/*更正代码如下:
$replaceClass   = new replaceStringFolder;
$replaceClass->oldString =   "http://211.157.122.160:8282/";
$replaceClass->newString =   "http://www.XXXX.net/";
$replaceClass->varFolder =   "/opt/shtml";(这里最后没有“/”,切记)
$replaceClass->doReplaceFolder();
*/