尚硅谷2022版Java Web之Servlet入门笔记-CFANZ编程社区

先上代码

add.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="add" method="post">
        名称：<input type="text" name="fname"/><br/>
        价格：<input type="text" name="price"/><br/>
        库存：<input type="text" name="fcount"/><br/>
        备注：<input type="text" name="remark"/><br/>
        <input type="submit" value="添加"/>
    </form>
</body>
</html>

AddServlet.java

package com.shangguigu.servlets;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class AddServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String fname = request.getParameter("fname");
        String priceStr = request.getParameter("price");
        Integer price = Integer.parseInt(priceStr);
        String fcountStr = request.getParameter("fcount");
        Integer fcount = Integer.parseInt(fcountStr);
        String remark = request.getParameter("remark");

        System.out.println("fname =" + fname);
        System.out.println("price =" + price);
        System.out.println("fcount =" + fcount);
        System.out.println("remark =" + remark);
    }
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <servlet>
        <servlet-name>AddServlet</servlet-name>
        <servlet-class>com.shangguigu.servlets.AddServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>AddServlet</servlet-name>
        <url-pattern>/add</url-pattern>
        <!--
        1.用户发送请求，action=add
        2.项目中，web.xml中找到url-pattern = /add
        3.找servlet-name = AddServlet
        4.找和servlet-mapping中servlet-name一致的servlet
        5.找servlet-class -> com.shangguigu.servlets.AddServlet
        6.用户发送的是post请求（method = post），因此tomcat会执行AddServlet中doPost方法
        -->
    </servlet-mapping>
</web-app>

具体步骤

在src下新建java类com.shangguigu.servlet.AddServlet

让AddServlet继承HttpServlet

public class AddServlet extends HttpServlet{
    
}

HttpServlet类在servlet-api.jar中，要导包

方法一：把包导到library中

方法二：添加tomcat依赖

“文件”-“项目结构”然后“Modules”-“项目文件夹（例如hello）”-“Dependencies”-“+”-“Library”-“tomcat”

servlet-api.jar已经被导入成功

doPost帮助你响应post请求

直接doPost快捷打出