Request header data acquisition request

Data acquisition request header

Method:
the Enumeration getHeaderNames (): Get all request header name
String getHeader (String name): Gets the value of the request header request header by name

package com.web.request;

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

/**
 * @ClassName: ${NAME}
 * @Description: TODO
 * @author: Doge_fang
 * @date: 2020/3/3  18:50
 */
@WebServlet("/requestDemo2")
public class RequestDemo2 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.获取所有请求头名称
        Enumeration<String> headerNames = request.getHeaderNames();
        //2.遍历
        while(headerNames.hasMoreElements()){
            String name = headerNames.nextElement();
            //根据名称获取请求头的值
            String header = request.getHeader(name);
            System.out.println(name + "-----" + header);

        }

    }
}

Will get the user-agent request header data:

package com.web.request;

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 java.io.IOException;

/**
 * @ClassName: ${NAME}
 * @Description: TODO
 * @author: Doge_fang
 * @date: 2020/3/3  19:01
 */
@WebServlet("/requestDemo3")
public class RequestDemo3 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取请求头user-agent数据
        String header = request.getHeader("user-agent");
        //判断浏览器版本
        if(header.contains("Chrome")){
            System.out.println("是谷歌");
        }else if(header.contains("Firefox")){
            System.out.println("是火狐");
        }

    }
}

Will get the referer request header data:

package com.web.request;

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 java.io.IOException;

/**
 * @ClassName: ${NAME}
 * @Description: TODO
 * @author: Doge_fang
 * @date: 2020/3/3  19:11
 */
@WebServlet("/requestDemo4")
public class RequestDemo4 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //演示获取请求头数据:referer
        String referer = request.getHeader("referer");
        System.out.println(referer);

        //防盗链
        if(referer != null){
            if(referer.contains("/test")){
                //是从本网站点击电影链接
                response.setContentType("text/html;charset=utf-8");
                response.getWriter().write("马上为您播放电影");
            }else {
                //盗链，盗取本网站电影链接
                response.setContentType("text/html;charset=utf-8");
                response.getWriter().write("无法播放，请上正规网站观看");
            }

        }


    }
}