程序如下：这个header指的是什么啊？

Question

import java.io.*;import java.util.*;import javax.servlet.*;import javax.servlet.http.*;public class RequestHeaderExample extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws IOException, ServletException{response.setContentType("text/html");PrintWriter out = response.getWriter();Enumeration e = request.getHeaderNames();while (e.hasMoreElements()) {String name = (String)e.nextElement();String value = request.getHeader(name);out.println(name + " = " + value);}}}

Answer 1

getHeader("string")得到指定键值对里的值。getHeaderName()得到所有的键，并存在一个Enumeration枚举类型里。

Answer 2

getHeaderNames()
Returns an enumeration of all the header names this request contains.

刚查得API