0057 Spring MVC如何获取HTTP请求头信息--URL中的动态参数--@RequestHeader--@CookieValue--@PathVariable

获取HTTP请求头信息

一个HTTP请求除了有参数和实体内容外还有HTTP请求头信息，Spring MVC也可以获取这部分信息

@RequestHeader解可以将请求头信息映射到处理方法的形参上

@CookieValue注解可以将Cookie映射到形参上

写个controller

package net.sonng.mvcdemo.controller;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.CookieValue;

import org.springframework.web.bind.annotation.RequestHeader;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.servlet.ModelAndView;

@Controller

public class HeaderController {

    @RequestMapping(value="/getHeader",method=RequestMethod.GET)

    public ModelAndView getHeader(

            @RequestHeader("Host") String host,

            @RequestHeader("User-Agent") String userAgent,

            @RequestHeader("Accept") String accept,

            @RequestHeader("Accept-Language") String acceptLanguage,

            @RequestHeader("Accept-Encoding") String acceptEncoding,

            @RequestHeader("Cookie") String cookie,

            @RequestHeader("Connection") String conn,

            @CookieValue("JSESSIONID") String cookie2){

        //@RequestHeader将http请求头信息赋值给形参

        //@CookieValue直接将请求头中的cookie的值赋值给形参

        ModelAndView mav=new ModelAndView();

        mav.addObject("host", host);

        mav.addObject("userAgent", userAgent);

        mav.addObject("accept", accept);

        mav.addObject("acceptLanguage", acceptLanguage);

        mav.addObject("acceptEncoding", acceptEncoding);

        mav.addObject("cookie", cookie);

        mav.addObject("conn", conn);

        mav.addObject("cookie2", cookie2);

        mav.setViewName("result");  //返回值是个字符串，就是视图名

        return mav;

    }

}

写个result.jsp作视图

<%@page pageEncoding="utf-8"

        contentType="text/html;charset=utf-8" %>

<html>

    <head>

        <title>返回结果</title>

    </head>

    <body style="color:blue;font-size:18px">

        您的请求头信息为：<br>

        Host: ${host }<br><br><br>

        User-Agent: ${userAgent }<br><br><br>

        Accept: ${accept }<br><br><br>

        Accept-Language: ${acceptLanguage }<br><br><br>

        Accept-Encoding: ${acceptEncoding }<br><br><br>

        Cookie: ${cookie }<br><br><br>

        Connection: ${conn }<br><br><br>

        cookie2:${cookie2 }<br><br><br>

    </body>

</html>

直接访问，可以看到jsp页面列出了这个http请求的头信息和cookie

您的请求头信息为：

Host: localhost:8080

User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:52.0) Gecko/20100101 Firefox/52.0

Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8

Accept-Language: zh-CN,zh;q=0.8,en-US;q=0.5,en;q=0.3

Accept-Encoding: gzip, deflate

Cookie: {JSESSIONID=javax.servlet.http.Cookie@3c915cc} //奇怪的是，输出的是个Cookie对象

Connection: keep-alive

cookie2:304FDCF278E823F2F2B8850BD7B8B8DC

获取请求URL中的动态参数

@PathVariable注解可以获取请求URL中的动态参数，这样就把url中“?”后面或者http实体中的部分参数，转移到了一个url中，多个url就映射到了一个方法上

写个Controller

package net.sonng.mvcdemo.controller;

import org.springframework.stereotype.Controller;

import org.springframework.ui.Model;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

@Controller

public class PathVariableTestController {

    @RequestMapping("/book/{isbn}") //@PathVariable把url中的动态参数传递给了形参，这里的{isbn}貌似还支持正则

    public String path(@PathVariable("isbn") String bookid,Model model){

         model.addAttribute("isbn", bookid);

         return "result";

    }

}

视图result.jsp

<%@page pageEncoding="utf-8"

        contentType="text/html;charset=utf-8" %>

<html>

    <head>

        <title>返回结果</title>

    </head>

    <body style="color:blue;font-size:18px">

        您请求的书籍的ISBN为：${isbn }

    </body>

</html>

直接请求：http://localhost:8080/mvcdemo/book/9787111336242 ，输出如下：

您请求的书籍的ISBN为：9787111336242