对post请求方式，我们需要明确表单内容的类型，一般情况下，直接提交data参数即可，但如果前端对此有所校验，就需要根据实际情况进行调整。

post form-data
这里我自己搭建了个简单的登陆界面
源码如下 login.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" import="java.util.*"  pageEncoding="utf-8" %>
<%
        String path = request.getContextPath();
        String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
        System.out.println(basePath);
%>


    




    
        
            
        
        用户名:
        密码:
        
            
                
            
        
    

运行界面:

用于处理登陆请求的loginServlet.java如下：

@WebServlet("/loginServlet")
public class loginServlet extends HttpServlet {
    //doGet实现页面转发
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.getRequestDispatcher("/login.jsp").forward(req,resp);
        System.out.println("访问了login.jsp");
    }
    //doPost处理post请求
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        System.out.println("username");
        req.getSession().setAttribute("username",username);
        String path = req.getContextPath();
        resp.sendRedirect(path + "/index/main.jsp");
    }
}

登陆成功后的main.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    


这是主页
welcome you ,${username}

我们填写账号，密码后点击登陆
同时打开dev-tools 看一下请求情况



接着用python模拟看看
python代码如下：

import requests

start_url = 'http://localhost:8080/loginServlet'
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36'
}
data = {
    'username': 'aaa',
    'password': 'aaa'
}
response = requests.post(start_url,headers=headers,data=data)
print(response.text)

响应结果:

可以看到成功了

首先我们来看一个例子
url:aHR0cHM6Ly93d3cua3VhaXNob3UuY29tL3Byb2ZpbGUvM3h4Ymt3ZDhta250ZWFj

先抓包分析接口

payload:

注意我这里圈起来的content-type:用于定义网络文件的类型和网页的编码，决定文件接收方将以什么形式、什么编码读取这个文件。这意味这我们直接以data的形式post，或许不行了。可以尝试一下

这里我们使用json = data进行post

response = session.post(self.start_url,headers=self.headers,json=self.data)

可以看到成功请求到了
请求代码如下:

class ksSpider(object):
    def __init__(self):
        self.start_url = "https://www.kuaishou.com/graphql"
        self.headers = {

            'Cookie': 'kpf=PC_WEB; kpn=KUAISHOU_VISION; clientid=3; did=web_74dfd4a4a602c0350b9d5a6715e61e87',
            'Referer': 'https://www.kuaishou.com/profile/3xxbkwd8mknteac',
            'User-Agent': random.choice(USER_AGENT_LIST)
        }
        self.data = {"operationName":"visionProfilePhotoList","variables":{"userId":"3xxbkwd8mknteac","pcursor":"1.637041162378E12","page":"profile"},"query":"fragment photoContent on PhotoEntity {n  idn  durationn  captionn  likeCountn  viewCountn  realLikeCountn  coverUrln  photoUrln  photoH265Urln  manifestn  manifestH265n  videoResourcen  coverUrls {n    urln    __typenamen  }n  timestampn  expTagn  animatedCoverUrln  distancen  videoRation  likedn  stereoTypen  profileUserTopPhoton  __typenamen}nnfragment feedContent on Feed {n  typen  author {n    idn    namen    headerUrln    followingn    headerUrls {n      urln      __typenamen    }n    __typenamen  }n  photo {n    ...photoContentn    __typenamen  }n  canAddCommentn  llsidn  statusn  currentPcursorn  __typenamen}nnquery visionProfilePhotoList($pcursor: String, $userId: String, $page: String, $webPageArea: String) {n  visionProfilePhotoList(pcursor: $pcursor, userId: $userId, page: $page, webPageArea: $webPageArea) {n    resultn    llsidn    webPageArean    feeds {n      ...feedContentn      __typenamen    }n    hostNamen    pcursorn    __typenamen  }n}n"}
    def parse_start_url(self):
        response = session.post(self.start_url,headers=self.headers,json=self.data)
        print(response.text)

这里我换个url:
aHR0cDovL3d3dy53aGdnenkuY29tL1BvbGljaWVzQW5kUmVndWxhdGlvbnMvaW5kZXguaHRtbD91dG09c2l0ZXNfZ3JvdXBfZnJvbnQuMmVmNTAwMWYuMC4wLmZkNGU1ODMwMDhiYjExZWQ5ZjIzYjUzNmUyN2YwNmFk

我们先传入data进行post

data = {"categoryCode": "GovernmentProcurement", "pageSize": 15, "pageNo": 1}
        response = session.post(self.start_url,headers=self.headers,data=data).text

当然失败了

接着我们复制api的资源路径 /front/search/category 添加xhr断点

触发请求
关注scope


在控制台输出一下s[“data”],很明显是字符串

那么我们把Headers补全，试试post 这个字符串
代码如下:

data2 = "{"categoryCode":"GovernmentProcurement","pageSize":"15","pageNo":"2"}"

response = session.post(self.start_url,headers=self.headers,data=data2).text

成功
完整代码:

class wSpider(object):
    def __init__(self):
        self.start_url = "http://www.whggzy.com/front/search/category"
        self.headers = {

            "Content-Type": "application/json",
            "X-Requested-With": "XMLHttpRequest",
            'Cookie': 'acw_tc=2f624a2b16583799791827338e7686367845620cecc4e2a1b7ed6f85bbdd0a',
            'Referer': 'http://www.whggzy.com/PoliciesAndRegulations/index.html',
            'user-agent' : random.choice(USER_AGENT_LIST)
        }

    def parse_start_url(self):
        data = {"categoryCode": "GovernmentProcurement", "pageSize": 15, "pageNo": 1}
        data2 = "{"categoryCode":"GovernmentProcurement","pageSize":"15","pageNo":"2"}"

        response = session.post(self.start_url,headers=self.headers,data=data2).text
        print(response)

if __name__ == '__main__':
    w = wSpider()
    w.parse_start_url()

post的时候需要根据具体情况 大致来说表单用data= 表单字典用 json=;同时还可以通过xhr断点来确定发送的数据。