restful httpclient request中文乱码解决办法

public static String getPostJson(HttpServletRequest request){
String s = "";
try{
request.setCharacterEncoding("UTF-8");
ServletInputStream in = request.getInputStream();
int len = request.getContentLength();
if (len <= 0) {
return "";
}
byte[] buffer = new byte[len];
in.read(buffer);
s = new String(buffer,"UTF-8");
}catch(Exception re){
re.printStackTrace();
}
return s;
}