16.request获取请求头信息

 

package com.gyf.web.lesson16;

import java.io.IOException;
import java.io.OutputStream;
import java.util.Enumeration;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.sun.org.apache.regexp.internal.REUtil;

@WebServlet("/Lesson16Servlet1")
public class Lesson16Servlet1 extends HttpServlet{

    
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException {
   /*    request对象方法
        获得客户端请求头
        getHead(name)方法 
        getHeaders(String name)方法 
        getHeaderNames方法 */
        
        //获取请求头
        /*System.out.println(request.getHeader("User-Agent"));
        System.out.println(request.getHeader("Accept"));*/
        
        
        //获取所有请求头的名字
        /** Enumeration 集合*/
        Enumeration<String> e = request.getHeaderNames();
        
        //遍历元素
        while(e.hasMoreElements()){
            String headName = e.nextElement();
            System.out.println(headName + ":" + request.getHeader(headName));
        }
        
        response.getWriter().write("xxx");
    }
}