回顾Servlet

1.新建一个Maven工程当做父工程！pom依赖！ 
<!-- 依赖 -->
<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.1.9.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <version>2.5</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.2</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>
</dependencies>
 
2. 建立一个Moudle：springmvc-01-servlet ， 添加Web app的支持！
 
3.导入servlet 和 jsp 的 jar 依赖 
<dependency>
   <groupId>javax.servlet</groupId>
   <artifactId>servlet-api</artifactId>
   <version>2.5</version>
</dependency>
<dependency>
   <groupId>javax.servlet.jsp</groupId>
   <artifactId>jsp-api</artifactId>
   <version>2.2</version>
</dependency>
4. 编写一个Servlet类，用来处理用户的请求
package com.min.servlet;


public class HelloServlet extends HttpServlet {
   @Override
   protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       //1.获取前端参数
        String method = req.getParameter("method");
        if (method.equals("add")) {
            req.getSession().setAttribute("msg", "执行了add方法");
        }
        if (method.equals("delete")) {
            req.getSession().setAttribute("msg", "执行了delete方法");
        }
        //2.调用业务层
        //3.视图转发或重定向
       req.getRequestDispatcher("/WEB-INF/jsp/test.jsp").forward(req,resp);
       //resp.sendRedirect();  //重定向
  }

   @Override
   protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
       doGet(req,resp);
  }
}
5. 编写test.jsp，在WEB-INF目录下新建一个jsp的文件夹，新建test.jsp 
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
   <title>hello!</title>
</head>
<body>
${msg}
</body>
</html>
6.在web.xml中注册Servlet 
<?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>hello</servlet-name>
        <servlet-class>com.min.servlet.HelloServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>hello</servlet-name>
        <url-pattern>/hello</url-pattern>
    </servlet-mapping>

   <!-- <session-config>
        <session-timeout>15</session-timeout>
    </session-config>-->

   <!-- <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>-->
</web-app>
7.配置Tomcat，并启动测试
 

  • localhost:8080/hello?method=add

  • localhost:8080/hello?method=delete

 

MVC框架要做哪些事情

  1. 将url映射到java类或java类的方法 .

  2. 封装用户提交的数据 .

  3. 处理请求--调用相关的业务处理--封装响应数据 .

  4. 将响应的数据进行渲染 . jsp / html 等表示层数据 .

说明：

常见的服务器端MVC框架有：Struts、Spring MVC、ASP.NET MVC、Zend Framework、JSF；常见前端MVC框架：vue、angularjs、react、backbone；由MVC演化出了另外一些模式如：MVP、MVVM 等等....

 

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原文地址：https://www.cnblogs.com/m987/p/12857419.html