http所有请求头在Console中打印

1.目标：将http中的请求头全部打印在Console中

2.基本语句

        //1.获得指定的头
        String header = response.getHeader("User-Agert");
        System.out.println(header);

        //2.获得所有头的名称
        Enumeration<String> headerNames = request.getHeaderNames();
        while(headerNames.hasMoreElements()) {//判断是否还有下一个元素
            String nextElement = headerNames.nextElement();//获取headerNames集合中的请求头
            String header2 = request.getHeader(nextElement);//通过请求头得到请求内容
            System.out.println(nextElement+":"+header2);

3.运行结果

4.完整代码

package com.hdh.requesd;

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

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

public class requestHead extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 1.获得指定的头
        String header = response.getHeader("User-Agert");
        System.out.println(header);

        // 2.获得所有头的名称
        Enumeration<String> headerNames = request.getHeaderNames();
        while (headerNames.hasMoreElements()) {// 判断是否还有下一个元素
            String nextElement = headerNames.nextElement();// 获取headerNames集合中的请求头
            String header2 = request.getHeader(nextElement);// 通过请求头得到请求内容
            System.out.println(nextElement + ":" + header2);

        }

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

}