HTTP请求中的是字符串数据：
//字符串读取
void charReader(HttpServletRequest request) {
BufferedReader br = request.getReader();
String str, wholeStr = "";while((str = br.readLine()) != null){
wholeStr += str;
}
System.out.println(wholeStr);
}
//二进制读取
void binaryReader(HttpServletRequest request) {
int len = request.getContentLength();
ServletInputStream iii = request.getInputStream();
byte[] buffer = new byte[len];
iii.read(buffer, 0, len);
}
注意：
request.getInputStream(); request.getReader();和request.getParameter("key");这三个函数中任何一个函数执行一次后（可正常读取body数据），之后再执行就无效了。